Precision Time Protocol (PTP) provides time synchronization among devices with submicrosecond accuracy. It provides also precise frequency synchronization.

Basic concepts

PTP profile

PTP profiles (PTP standards) include:

· IEEE 1588 version 2—1588v2 defines high-accuracy clock synchronization mechanisms. It can be customized, enhanced, or tailored as needed. 1588v2 is the latest version.

· IEEE 802.1AS—802.1AS is introduced based on IEEE 1588. It specifies a profile for use of IEEE 1588-2008 for time synchronization over a virtual bridged local area network (as defined by IEEE 802.1Q). 802.1AS supports only point-to-point full-duplex Ethernet, IEEE 802.11, and IEEE 802.3 EPON links.

· SMPTE ST 2059-2—ST2059-2 is introduced based on IEEE 1588. It specifies a profile specifically for time synchronization of audio or video equipment in a professional broadcast environment. It includes a self-contained description of parameters, their default values, and permitted ranges.

· AES67-2015—AES67-2015 is introduced based on IEEE 1588. It specifies a profile specifically for time synchronization of professional equipment for broadcast, music production, and film and television post-production. It includes a self-contained description of parameters, their default values, and permitted ranges.

· ITU-T G.8275.1—G.8275.1 is introduced based on IEEE 1588. It is a precision time protocol telecom profile for phase and time synchronization with full timing support from the network.

· ITU-T G.8275.2—G.8275.2 is introduced based on IEEE 1588. It uses the client-server architecture, with the member clock nodes as clients and the master clock node as the server.

The clients and server first exchange Layer 3 unicast messages to establish clock links and then exchange PTP messages for the clients to be synchronized to the server.

The communication between the clients and server can traverse a Layer 2 network. Make sure a maximum of three Layer 2 devices exist on the communication path. The Layer 2 devices do not need to support PTP.

To ensure stable PTP message processing and time synchronization accuracy, do not use Layer 3 interfaces or Layer 2 interfaces converted from Layer 3 interfaces to connect the clients and server.

PTP domain

A PTP domain refers to a network or part of a network that is enabled with PTP. A PTP domain has only one reference clock called "grandmaster clock (GM)." All devices in the domain synchronize to the clock.

Clock node and PTP port (IEEE 1588 version 2, IEEE 802.1AS, SMPTE ST 2059-2, and AES67-2015)

A node in a PTP domain is a clock node. A port enabled with PTP is a PTP port. PTP defines the following types of basic clock nodes:

· Ordinary Clock (OC)—A PTP clock with a single PTP port in a PTP domain for time synchronization. It synchronizes time from its upstream clock node through the port. If an OC operates as the clock source, it sends synchronization time through a single PTP port to its downstream clock nodes.

· Boundary Clock (BC)—A clock with more than one PTP port in a PTP domain for time synchronization. A BC uses one of the ports to synchronize time from its upstream clock node. It uses the other ports to synchronize time to the relevant upstream clock nodes. If a BC operates as the clock source, such as BC 1 in Figure 1, it synchronizes time through multiple PTP ports to its downstream clock nodes.

· Transparent Clock (TC)—A TC does not keep time consistency with other clock nodes. A TC has multiple PTP ports. It forwards PTP messages among these ports and performs delay corrections for the messages, instead of performing time synchronization. TCs include the following types:

¡ End-to-End Transparent Clock (E2ETC)—Forwards all PTP packets in the network and supports calculation of the delay on the entire link.

¡ Peer-to-Peer Transparent Clock (P2PTC)—Forwards only Sync, Follow_Up, and Announce messages, terminates other PTP messages, and supports calculation of the delay on the entire link.

Figure 1 shows the positions of these types of clock nodes in a PTP domain.

Figure 1 Clock nodes in a PTP domain

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In addition to these basic types of clock nodes, PTP introduces hybrid clock nodes. For example, a TC+OC has multiple PTP ports in a PTP domain. One port is the OC type, and the others are the TC type.

A TC+OC forwards PTP messages through TC-type ports and performs delay corrections. In addition, it synchronizes time through its OC-type port. TC+OCs include these types: E2ETC+OC and P2PTC+OC.

Clock node and PTP port (ITU-T G.8275.1)

A node in a PTP domain is a clock node. A port enabled with PTP is a PTP port.

ITU-T G.8275.1 defines the following types of basic clock nodes:

· Telecom boundary clock (T-BC)—A clock node with more than one PTP port in a PTP domain for time synchronization. It uses one of the ports to synchronize time to its upstream clock node and uses the other ports to distribute time to the downstream clock nodes. If a T-BC operates as the clock source, it distributes time through multiple PTP ports to its downstream clock nodes.

· Telecom transparent Clock (T-TC)—A clock code that forwards non-P2P PTP messages in the network. The forwarding duration will be included in calculation of the entire link delay.

· Telecom time slave clock (T-TSC) —An OC clock node (as defined in IEEE 1588 version 2 and IEEE 802.1AS) that can act only as a member clock.

Figure 1 shows the positions of these basic clock nodes in a PTP domain.

Figure 2 Clock nodes and PTP ports in a PTP domain (ITU-T G.8275.1)

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Clock nodes and PTP ports (ITU-T G.8275.2)

ITU-T G.8275.2 defines the following types of basic clock nodes:

· Partial-support telecom boundary clock (T-BC-P)—A clock node with more than one PTP port in a PTP domain for time synchronization. It uses one of the ports to synchronize time to its upstream clock node and uses the other ports to distribute time to the downstream clock nodes. When a T-BC-P clock node is a clock source, it distributes time through multiple PTP ports to its downstream clock nodes.

· Partial-support telecom time slave clock (T-TSC-P)—A clock node with a single PTP port in a PTP domain for time synchronization. It synchronizes time from its upstream clock node through the port. It can operate only as a member clock.

Figure 3 shows the positions of these basic clock nodes in a PTP domain.

Figure 3 Clock nodes and PTP ports in a PTP domain (ITU-T G.8275.2)

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Technical standard

A PTP profile uses the parameters including time accuracy, time class, time source, and clock offset (log variance) to describe PTP clock source signals. Users can customize and supplement a PTP profile based on the network conditions to develop their own PTP technical standard.

Three PTP technical standards are available: the default technical standard, OAM technical standard, and Unicom technical standard. The default parameter values, the elected clock source, and PTP message processing vary by technical standard.

Master-member/subordinate relationship

The master-member/subordinate relationships between the clock nodes (except TCs) are automatically determined based on the Best Master Clock (BMC) algorithm. You can also manually specify a role for the clock nodes.

The master-member/subordinate relationship is defined as follows:

· Master/Member node—A master node sends a synchronization message, and a member node receives the synchronization message.

· Master/Member clock—The clock on a master node is a master clock (parent clock) The clock on a member node is a member clock.

· Master/Subordinate/Passive port—A master port sends a synchronization message, and a subordinate port receives the synchronization message. The master and subordinate ports can be on a BC or an OC. A port that neither receives nor sends synchronization messages is a passive port.

· Grant-port/request-port—A grant-port grants and provides PTP message service. A request-port requests and receives PTP message service. Typically, a grant-port is in master state. A request-port is in slave state when selected as the port for time synchronization and in listening state when not selected.

Clock source type

A clock node supports the following clock sources:

· Local clock source—38.88 MHz clock signals generated by a crystal oscillator inside the clock monitoring module.

· External clock source—Clock signals generated by an external clock device. The signals are received and sent by a 1PPS/ToD port on the MPU. It is also called a ToD clock source.

Grandmaster clock

As shown in Figure 1, the grandmaster clock (GM) is the ultimate source of time for clock synchronization in a PTP domain. It is elected automatically by the clock nodes in the PTP domain. The clock nodes exchange PTP messages and elect the GM by comparing the clock priority, time class, and time accuracy carried in the PTP messages.

You can also specify a GM manually.

Grandmaster clock selection and master-member/subordinate relationship establishment

IEEE 1588 version 2, IEEE 802.1AS, SMPTE ST 2059-2, and AES67-2015

A GM can be manually specified. It can also be elected through the BMC algorithm as follows:

1. The clock nodes in a PTP domain exchange announce messages and elect a GM by using the following rules in descending order:

a. Clock node with higher priority 1.

b. Clock node with higher time class.

c. Clock node with higher time accuracy.

d. Clock node with higher priority 2.

e. Clock node with a smaller port ID (containing clock number and port number).

The master nodes, member nodes, master ports, and subordinate ports are determined during the process. Then a spanning tree with the GM as the root is generated for the PTP domain.

2. The master node periodically sends announce messages to the member nodes. If the member nodes do not receive announce messages from the master node, they determine that the master node is invalid, and they start to elect another GM.

ITU-T G.8275.1

A GM can be manually specified. It can also be automatically elected through the BMC algorithm as follows:

1. The clock nodes in a PTP domain exchange announce messages and elect a GM by using the following rules in descending order of precedence:

a. Clock node with higher time class.

b. Clock node with higher time accuracy.

c. Clock node with higher priority 2.

d. Clock node with higher local priority.

You can use the ptp priority clock-source command to set the local priority for the local node.

To set a local priority for the peer node, use the ptp local-priority command to set a local priority for the PTP interface connected to the peer node. This priority will be used as the local priority of the peer node.

e. Whether the time class values of the clock nodes are smaller than or equal to 127.

- If the time class values of the clock nodes are smaller than or equal to 127, two or more clock nodes are elected GMs in the PTP domain. A member node selects the GM nearer to it as its master node. Two or more spanning trees are generated. No PTP messages are exchanged between the trees.

- If the time class values of the clock nodes are greater than 127, the clock node with a smaller port ID (containing clock number and port number) will be the GM.

The master nodes, member nodes, master ports, and subordinate ports are determined during the process.

ITU-T G.8275.2

This profile allows using two approaches to establish a synchronization tree.

· Specifying the grant-ports and request-ports—The request-ports request announce messages from a specific grant-port and the grant-port grants and provides announce messages to the request-ports, to quickly determine the GM. Plan in advance to ensure that the device where the grant-port resides has the best clock source. If the device does not have the best clock source, the request-ports will be in listening state, resulting in time synchronization failure.

· Dynamic election—All clock ports exchange announce messages to elect the GM and establish a synchronization tree.

In a PTP domain, use the same approach on the clock nodes to establish a synchronization tree as a best practice. If you apply the two approaches on the same device, both the announce messages requested by the request-port and received during dynamic election participate in Alternate BMC calculation for GM election. As a result, the request-ports might not be selected as the ports for clock synchronization.

Synchronization mechanism

After master-member relationships are established between the clock nodes, the master and member clock nodes exchange PTP messages and record the message transmit and receive time. Based on the timestamps, each member clock calculates the path delay and time offset between them and the master clock and adjusts their time accordingly for time synchronization with the master clock.

PTP defines two path delay measurement mechanisms: Request_Response_ and Peer Delay, both of which are based on network symmetry.

Request_Response

The Request_Response mechanism measures the average path delay between the master and member clock nodes by using the PTP messages as shown in Figure 4. A TC between master and member clock nodes does not calculate the path delay. It forwards PTP messages and carries the Sync message residence time on it to the downstream clock node.

This mechanism can be implemented in one of the following two modes:

· Two-step mode—t1 is carried in the Follow_Up message as shown in Figure 4.

· Single-step mode—t1 is carried in the Sync message, and no Follow_Up message is sent.

Figure 4 shows the Request_Response mechanism in two-step mode.

1. The master clock sends a Sync message to the member clock, and records the sending time t1. Upon receiving the message, the member clock records the receiving time t2.

2. After sending the Sync message, the master clock immediately sends a Follow_Up message that carries time t1.

3. The member clock sends a Delay_Req message to the master clock, and records the sending time t3. Upon receiving the message, the master clock records the receiving time t4.

4. The master clock returns a Delay_Resp message that carries time t4.

After this procedure, the member clock obtains all the four timestamps and can make the following calculations:

· Round-trip delay between the master and member clocks: (t2 – t1) + (t4 – t3)

· One-way delay between the master and member clocks: [(t2 – t1) + (t4 – t3)] / 2

· Offset between the member and master clocks: (t2 – t1) – [(t2 – t1) + (t4 – t3)] / 2 or [(t2 – t1) – (t4 – t3)] / 2

Figure 4 Request_Response mechanism (two-step node)

Peer Delay

The Peer Delay mechanism measures the average path delay between two clock nodes by using Pdelay messages. The two clock nodes (BC, TC, or OC) implementing this mechanism send Pdelay messages to each other, and calculate the one-way link delay between them independently. The message interaction process and delay calculation method are identical on the two nodes. TCs that exist between master and member clock nodes divide the synchronization path into multiple links and participate in delay calculation. The link delays and Sync message residence time on the TCs are carried to downstream nodes.

This mechanism can be implemented in one of the following two modes:

· Two-step mode

As shown in Figure 5, Pdelay messages include Pdelay_Req, Pdelay_Resp, and Pdelay_Resp_Follow_Up messages. t2 is carried in the Pdelay_Resp message, and t3 is carried in the Pdelay_Resp_Follow_Up message.

· Single-step mode:

Pdelay messages include Pdelay_Req and Pdelay_Resp messages. t3 – t2 is carried in the Pdelay_Resp, and no Pdelay_Resp_Follow_Up message is sent.

Figure 5 uses Clock node B as an example to describe the Peer Delay mechanism.

1. Clock node B sends a Pdelay_Req message to Clock node A, and records the sending time t1. Upon receiving the message, Clock node A records the receiving time t2.

2. Clock node A sends a Pdelay_Req message that carries t2 to Clock node B, and records the sending time t3. Upon receiving the message, Clock node B records the receiving time t4.

3. Clock node A immediately sends a Pdelay_Resp_Follow_Up message carrying t3 to Clock node B after sending the Pdelay_Req message.

After this procedure, Clock node B obtains all the four timestamps and can make the following calculations:

· Round-trip delay between Clock node A and Clock node B: (t2 – t1) + (t4 – t3)

· One-way delay between Clock node A and Clock node B: [(t2 – t1) + (t4 – t3)] / 2 = [(t4 – t1) – (t3 – t2)] / 2

· Time offset between the member clock and the master clock: Sync message receiving time on the member clock – Sync message sending time on the master clock – Total one-way delays on all links – Total Sync message residence time on all TCs.

Figure 5 Peer Delay mechanism (two-step mode)

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Protocols and standards

· IEEE Std 1588-2008, IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems, 2008

· IEEE 802.1AS, Timing and Synchronization for Time-Sensitive Applications in Bridged Local Area Networks

· SMPTE ST 2059-2, SMPTE Profile for Use of IEEE-1588 Precision Time Protocol in Professional Broadcast Applications

· AES67-2015, AES Standard for Audio Applications of Networks-High-Performance Streaming Audio-Over-IP Interoperability, 2015

· ITU-T G.8275.1, Precision time protocol telecom profile for phase/time synchronization with full timing support from the network

· ITU-T G.8275.2, Precision time protocol telecom profile for phase/time synchronization with partial timing support from the network

Restrictions and guidelines: PTP configuration

Before configuring PTP, determine the PTP profile and define the scope of the PTP domain and the role of every clock node.

In a PTP domain that runs the IEEE 1588 version 2 or IEEE 802.1AS PTP profile, specify the BC or OC clock node type for the devices in the domain as a best practice. A TC clock node is mainly used for forwarding PTP messages. When receiving a PTP message, a TC multicasts the message from all its PTP interfaces except the inbound interface of the PTP message. To deploy a TC in the domain, plan the TC location and number and location of PTP interfaces on the TC manually to prevent PTP forwarding loops.

PTP tasks at a glance

Configuring PTP (IEEE 1588 version 2)

1. Specifying PTP for obtaining the time

2. Specifying a PTP profile

Specify the IEEE 1588 version 2 PTP profile.

3. Configuring clock nodes

¡ Specifying a clock node type

¡ (Optional.) Configuring an OC to operate only as a member clock

4. Specifying a PTP domain

5. Enabling PTP on a port

6. Configuring PTP ports

¡ (Optional.) Configuring the role of a PTP port

¡ Configuring the mode for carrying timestamps

¡ Specifying a delay measurement mechanism for a BC or an OC

¡ Configuring one of the ports on a TC+OC clock as an OC-type port

7. (Optional.) Configuring PTP message transmission and receipt

¡ Setting the interval for sending announce messages and the timeout multiplier for receiving announce messages

¡ Setting the interval for sending Pdelay_Req messages

¡ Setting the interval for sending Sync messages

¡ Setting the minimum interval for sending Delay_Req messages

8. (Optional.) Configuring parameters for PTP messages

¡ Specifying the IPv4 UDP transport protocol for PTP messages

¡ Configuring a source IP address for multicast PTP messages transmitted over IPv4 UDP

¡ Configuring a destination IP address for unicast PTP messages transmitted over IPv4 UDP

¡ Configuring the MAC address for non-Pdelay messages

¡ Setting a DSCP value for PTP messages transmitted over UDP

¡ Specifying a VLAN tag for PTP messages

¡ Disabling PTP path tracing

9. (Optional.) Specifying the maximum number of removed steps (clock nodes) from the GM to the device

10. (Optional.) Enabling the device to notify the downstream nodes of its time synchronization state

11. (Optional.) Adjusting and correcting clock synchronization

¡ Setting the delay correction value

¡ Calculating the TAI based on the UTC time

¡ Configuring ToD input or output

12. (Optional.) Setting clock source parameters

13. (Optional.) Configuring a priority for a clock

14. (Optional.) Configuring PTP logging

Configuring PTP (IEEE 802.1AS)

1. Specifying PTP for obtaining the time

2. Specifying a PTP profile

Specify the IEEE 802.1AS PTP profile.

3. Configuring clock nodes

¡ Specifying a clock node type

¡ (Optional.) Configuring an OC to operate only as a member clock

4. (Optional.) Specifying a PTP domain

5. Enabling PTP on a port

6. Configuring PTP ports

¡ (Optional.) Configuring the role of a PTP port

¡ Specifying a delay measurement mechanism for a BC or an OC

7. (Optional.) Configuring PTP message transmission and receipt

¡ Setting the interval for sending announce messages and the timeout multiplier for receiving announce messages

¡ Setting the interval for sending Pdelay_Req messages

¡ Setting the interval for sending Sync messages

¡ Specifying a VLAN tag for PTP messages

¡ Disabling PTP path tracing

8. (Optional.) Specifying the maximum number of removed steps (clock nodes) from the GM to the device

9. (Optional.) Adjusting and correcting clock synchronization

¡ Setting the delay correction value

¡ Calculating the TAI based on the UTC time

¡ Configuring ToD input or output

10. (Optional.) Setting clock source parameters

11. (Optional.) Configuring a priority for a clock

Configuring PTP (SMPTE ST 2059-2)

1. Specifying PTP for obtaining the time

2. Specifying a PTP profile

Specify the SMPTE ST 2059-2 PTP profile.

3. Configuring clock nodes

¡ Specifying a clock node type

¡ (Optional.) Configuring an OC to operate only as a member clock

4. (Optional.) Specifying a PTP domain

5. Enabling PTP on a port

6. Configuring PTP ports

¡ (Optional.) Configuring the role of a PTP port

¡ Configuring the mode for carrying timestamps

¡ Specifying a delay measurement mechanism for a BC or an OC

7. (Optional.) Configuring PTP message transmission and receipt

¡ Setting the interval for sending announce messages and the timeout multiplier for receiving announce messages

¡ Setting the interval for sending Pdelay_Req messages

¡ Setting the interval for sending Sync messages

¡ Setting the minimum interval for sending Delay_Req messages

8. (Optional.) Configuring parameters for PTP messages

¡ Configuring a source IP address for multicast PTP messages transmitted over IPv4 UDP

¡ Configuring a destination IP address for unicast PTP messages transmitted over IPv4 UDP

¡ Setting a DSCP value for PTP messages transmitted over UDP

¡ Specifying a VLAN tag for PTP messages

¡ (Disabling PTP path tracing

9. (Optional.) Specifying the maximum number of removed steps (clock nodes) from the GM to the device

10. (Optional.) Adjusting and correcting clock synchronization

¡ Setting the delay correction value

¡ Calculating the TAI based on the UTC time

¡ Configuring ToD input or output

11. (Optional.) Setting clock source parameters

12. (Optional.) Configuring a priority for a clock

Configuring PTP (AES67-2015)

1. Specifying PTP for obtaining the time

2. Specifying a PTP profile

Specify the AES67-2015 PTP profile.

3. Configuring clock nodes

¡ Specifying a clock node type

¡ (Optional.) Configuring an OC to operate only as a member clock

4. (Optional.) Specifying a PTP domain

5. Enabling PTP on a port

6. Configuring PTP ports

¡ (Optional.) Configuring the role of a PTP port

¡ Configuring the mode for carrying timestamps

¡ Specifying a delay measurement mechanism for a BC or an OC

¡ Configuring one of the ports on a TC+OC clock as an OC-type port

7. (Optional.) Configuring PTP message transmission and receipt

¡ Setting the interval for sending announce messages and the timeout multiplier for receiving announce messages

¡ Setting the interval for sending Pdelay_Req messages

¡ Setting the interval for sending Sync messages

¡ Setting the minimum interval for sending Delay_Req messages

8. (Optional.) Configuring parameters for PTP messages

¡ Configuring a source IP address for multicast PTP messages transmitted over IPv4 UDP

¡ Configuring a destination IP address for unicast PTP messages transmitted over IPv4 UDP

¡ Setting a DSCP value for PTP messages transmitted over UDP

¡ Specifying a VLAN tag for PTP messages

¡ Disabling PTP path tracing

9. (Optional.) Specifying the maximum number of removed steps (clock nodes) from the GM to the device

10. (Optional.) Adjusting and correcting clock synchronization

¡ Setting the delay correction value

¡ Calculating the TAI based on the UTC time

¡ Configuring ToD input or output

11. (Optional.) Setting clock source parameters

12. (Optional.) Configuring a priority for a clock

Configuring PTP (ITU-T G.8275.1)

1. Specifying PTP for obtaining the time

2. Specifying a PTP profile

Specify the ITU-T G.8275.1 PTP profile.

3. Specifying a clock node type

4. Specifying a PTP domain

5. Enabling PTP on a port

6. Configuring PTP ports

¡ (Optional.) Configuring the role of a PTP port

¡ Configuring the mode for carrying timestamps

¡ Enabling NotSlave on a PTP port

7. (Optional.) Configuring PTP message transmission and receipt

¡ Setting the interval for sending announce messages and the timeout multiplier for receiving announce messages

¡ Setting the interval for sending Sync messages

¡ Setting the minimum interval for sending Delay_Req messages

8. (Optional.) Configuring parameters for PTP messages

¡ Configuring the MAC address for non-Pdelay messages

¡ Specifying a VLAN tag for PTP messages

¡ Disabling PTP path tracing

9. (Optional.) Specifying the maximum number of removed steps (clock nodes) from the GM to the device

10. (Optional.) Enabling the device to notify the downstream nodes of its time synchronization state

11. (Optional.) Adjusting and correcting clock synchronization

¡ Setting the delay correction value

¡ Calculating the TAI based on the UTC time

¡ Configuring ToD input or output

12. (Optional.) Setting clock source parameters

13. (Optional.) Configuring a priority for a clock

14. (Optional.) Configuring PTP logging

Configuring PTP (ITU-T G.8275.2)

1. Specifying PTP for obtaining the time

2. Specifying a PTP profile

Specify the ITU-T G.8275.2 PTP profile.

3. Specifying a clock node type

4. Specifying a PTP domain

5. Enabling PTP on a port

6. Configuring PTP ports

¡ (Optional.) Configuring the role of a PTP port

¡ Configuring the mode for carrying timestamps

¡ Enabling NotSlave on a PTP port

¡ Enabling unicast negotiation on PTP ports

7. (Optional.) Configuring PTP message transmission and receipt

¡ Setting the interval for sending announce messages and the timeout multiplier for receiving announce messages

¡ Setting the interval for sending Sync messages

¡ Setting the minimum interval for sending Delay_Req messages

¡ Setting the interval for sending Delay-Resp messages

8. (Optional.) Configuring parameters for PTP messages

¡ Configuring the MAC address for non-Pdelay messages

¡ Specifying a VLAN tag for PTP messages

¡ Disabling PTP path tracing

9. (Optional.) Specifying the maximum number of removed steps (clock nodes) from the GM to the device

10. (Optional.) Adjusting and correcting clock synchronization

¡ Setting the delay correction value

¡ Calculating the TAI based on the UTC time

¡ Configuring ToD input or output

11. (Optional.) Setting clock source parameters

12. (Optional.) Configuring a priority for a clock

13. (Optional.) Configuring PTP logging

Specifying PTP for obtaining the time

1. Enter system view.

system-view

2. Specify PTP for obtaining the time.

clock protocol ptp

By default, the device uses NTP to synchronize the system time.

For more information about the clock protocol command, see device management commands in Fundamentals Command Reference.

Specifying a PTP profile

Restrictions and guidelines

You must specify a PTP profile before configuring PTP settings. Changing the PTP profile clears all settings under the profile.

Procedure

1. Enter system view.

system-view

2. Specify a PTP profile.

ptp profile { 1588v2 | 8021as | aes67-2015 | st2059-2 | g8275.1| g8275.2 }

By default, no PTP profile is configured, and PTP is not running on the device.

Configuring clock nodes

Specifying a clock node type

Restrictions and guidelines

· You can configure this command only after you have specified a PTP profile for the device.

· You can specify only one clock node type for the device.

· Changing or removing the clock node type will restore the default settings of the PTP profile.

Procedure

1. Enter system view.

system-view

2. Specify a clock node type for the device.

IEEE 1588v2 PTP profile:

ptp mode { bc | e2etc | e2etc-oc | oc | p2ptc | p2ptc-oc }

IEEE 802.1AS PTP profile:

ptp mode { bc | oc | p2ptc | p2ptc-oc }

AES67-2015 and SMPTE ST 2059-2 PTP profiles:

ptp mode { bc | e2etc | oc | p2ptc }

ITU-T G.8275.1 PTP profile:

ptp mode { t-bc | t-tc | t-tsc }

ITU-T G.8275.2 PTP profile:

ptp mode { t-bc-p | t-tsc-p }

By default, no clock node type is specified.

Configuring an OC to operate only as a member clock

About this task

An OC can operate either as a master clock to send synchronization messages or as a member clock to receive synchronization messages. This task allows you to configure an OC to operate only as a member clock.

If an OC is operating only as a member clock, you can use the ptp force-state command to configure its PTP port as a master port or passive port.

Restrictions and guidelines

This task is applicable only to OCs.

Procedure

1. Enter system view.

system-view

2. Configure the OC to operate only as a member clock.

ptp slave-only

By default, an OC operates as a master or member clock.

Specifying a PTP domain

About this task

Within a PTP domain, all devices follow the same rules to communicate with each other. Devices in different PTP domains cannot exchange PTP messages.

Procedure

1. Enter system view.

system-view

2. Specify a PTP domain for the device.

ptp domain value

By default, no PTP domain exists.

Do not configure the same domain on different PTP instances.

Enabling PTP on a port

About this task

A port enabled with PTP becomes a PTP port.

Restrictions and guidelines

You can enable PTP on only one port on an OC.

To enable PTP on a Layer 3 Ethernet interface that has been assigned to a VPN instance, you must specify this VPN instance in the ptp source ip-address vpn-instance vpn-instance-name command if PTP messages are to be transmitted in multicast mode over IPv4 UDP.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Enable PTP on the port.

ptp enable

By default, PTP is disabled on a port.

Configuring PTP ports

Configuring the role of a PTP port

About this task

You can configure the master, passive, or slave role for a PTP port.

For an OC that operates in slave-only mode, you can perform this task to change its PTP port role to master or slave.

Restrictions and guidelines

After you change the role of a PTP port, you must execute the ptp active force-state command to activate the port role configuration.

You can configure one subordinate port for a device.

· This task is not available for a T-TSC, T-TSC-P, or T-BC-P clock node.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

3. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

4. Configure the role of the PTP port.

ptp force-state { master | passive | slave }

By default, the PTP port role is automatically calculated through BMC.

5. Return to system view.

quit

6. Activate the port role configuration.

ptp active force-state

By default, the port role configuration is not activated.

Configuring the mode for carrying timestamps

‌About this task

Timestamps can be carried in either of the following modes:

· Single-step mode—The Sync message (in the Request_Response or Peer Delay mechanism) and Pdelay_Resp message (in the Peer Delay mechanism) carry their sending timestamps by themselves.

· Two-step mode—The Sync message (in the Request_Response or Peer Delay mechanism) and Pdelay_Resp message (in the Peer Delay mechanism) do not carry their sending timestamps by themselves. The subsequent messages carry their timestamps.

Restrictions and guidelines

The IEEE 802.1AS PTP profile supports only the two-step mode.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

3. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

4. Configure the mode for carrying timestamps.

ptp clock-step { one-step | two-step }

By default, the two-step mode is used for carrying timestamps.

Specifying a delay measurement mechanism for a BC or an OC

About this task

PTP defines two transmission delay measurement mechanisms: Request_Response and Peer Delay. For correct communication, ports on the same link must share the same delay measurement mechanism.

Restrictions and guidelines

When the PTP profile is IEEE 1588 version 2, SMPTE ST 2059-2, or AES67-2015, the following restrictions apply:

· This task is available only for a BC or OC clock node.

· This task is not available for an E2ETC, E2ETC+OC, P2PTC, or P2PTC+OC clock node. The E2ETC and E2ETC+OC clock nodes support both request-response and peer delay measurement mechanisms. A P2PTC clock node supports only the peer delay measurement mechanism.

The IEEE 802.1AS PTP profile supports only the peer delay measurement mechanism and does not support this task.

The ITU-T G.8275.1 PTP profile supports only the request-response delay measurement mechanism and does not support this task.

The ITU-T G.8275.2 PTP profile supports only the request-response delay measurement mechanism and does not support this task.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Specify a delay measurement mechanism for a BC or an OC.

ptp delay-mechanism { e2e | p2p }

The default delay measurement mechanism depends on the PTP profile.

¡ When the PTP profile is IEEE 1588 version 2, AES67-2015, or SMPTE ST 2059-2, the request-response delay measurement mechanism applies.

¡ When the PTP profile is IEEE 802.1AS, the peer delay measurement mechanism applies.

¡ When the PTP profile is ITU-T G.8275.1, the request-response delay measurement mechanism applies.

¡ When the PTP profile is ITU-T G.8275.2, the request-response delay measurement mechanism applies.

Configuring one of the ports on a TC+OC clock as an OC-type port

About this task

All ports on a TC+OC (E2ETC+OC or P2PTC+OC) are TC-type ports by default. This feature allows you to configure one of the ports on a TC+OC clock as an OC-type port.

Restrictions and guidelines

This task is applicable only to E2ETC+OCs and P2PTC+OCs.

This task is not available for the SMPTE ST 2059-2 PTP profile.

This task is not available for the ITU-T G.8275.1 or ITU-T G.8275.2 PTP profile.

For time synchronization accuracy, the OC-type port on an E2ETC+OC or P2PTC+OC must be specified as the master port.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Configure the port type as OC.

ptp port-mode oc

By default, the port type for all ports on a TC+OC is TC.

Enabling NotSlave on a PTP port

About this task

The NotSlave feature, supported only by the ITU-T G.8275.1 and ITU-T G.8275.2 PTP profiles, enables a PTP port to select the clock node where it resides as the master node. You can use this feature to control master/member role of the clock nodes. For automatic master/member clock node selection in a PTP domain under the ITU-T G.8275.1 or ITU-T G.8275.2 PTP profile, you must disable NotSlave on all PTP ports.

Restrictions and guidelines

Only the ITU-T G.8275.1 and ITU-T G.8275.2 PTP profiles support this task.

· When the PTP profile is ITU-T G.8275.1, you can configure this task only on a T-BC or T-TC clock node.

· When the PTP profile is ITU-T G.8275.1, you can configure this task only on a T-BC-P clock node.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Disable NotSlave.

ptp notslave disable.

Enabling unicast negotiation on PTP ports

About this task

The ITU-T G.8275.2 PTP profile allows establishing a PTP synchronization tree by specifying the request-ports and master-ports.

A request-port initiates a connection request to a specific grant-port. Then they negotiate PTP parameters and exchange PTP messages to synchronize the client time to the server. Plan the network in advance and specify the ports on the member (client) clock nodes as request-ports and the ports on the master (server) clock nodes as grant-ports.

Restrictions and guidelines

Only the ITU-T G.8275.2 PTP profile supports this task.

Procedure

1. Enter system view.

system-view

2. Enter Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Enable unicast negotiation and specify the port as a grant-port or request port.

ptp unicast-negotiate { grant-port | request-port }

Configuring PTP message transmission and receipt

Setting the interval for sending announce messages and the timeout multiplier for receiving announce messages

About this task

A master node sends announce messages to the member nodes at the specified interval. If a member node does not receive any announce message from the master node after the timeout expires, it determines that the master node is invalid. The timeout = timeout multiplier × interval at which the master node sends announce messages.

About this task

A master node periodically sends announce messages at the specified interval. If a member node does not receive any announce message from the master node after the timeout expires, it determines that the master node is invalid. The timeout = timeout multiplier × interval at which the master node sends announce messages.

The configuration of the interval at which the master node sends announce messages depends on the PTP profile in the PTP domain.

· PTP profile other than ITU-T G.8275.2, or ITU-T G.8275.2 PTP profile not using unicast negotiation—You must configure the interval on the master node.

· ITU-T G.8275.2 PTP profile using unicast negotiation—You must configure the interval on the request-port of the client. The request-port uses the configured interval to negotiate with the grant-port on the server for the interval at which the grant-port sends announce messages to the client. If the negotiation succeeds, the grant-port sends announce messages at the configured interval to the client. If the negotiation fails, the grant-port does not send announce messages to the client.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Set the interval for sending announce messages.

ptp announce-interval interval

The default settings vary by PTP profile.

¡ IEEE 1588 version 2 or AES67-2015—The interval argument value is 1 and the interval for sending announce messages is 2 (21) seconds.

¡ IEEE 802.1AS—The interval argument value is 0 and the interval for sending announce messages is 1 (20)second.

¡ SMPTE ST 2059-2—The interval argument value is –2 and the interval for sending announce messages is 1/4 (2-2) seconds.

¡ ITU-T G.8275.1 and ITU-T G.8275.2—The interval argument value is –3 and the interval for sending announce messages is 1/8 (2-3) seconds.

4. Set the number of intervals before a timeout occurs.

ptp announce-timeout multiple-value

This command is not supported when the PTP profile is ITU-T G.8275.2.

Setting the interval for sending Pdelay_Req messages

Restrictions and guidelines

This task is not available under the ITU-T G.8275.1 or ITU-T G.8275.2 PTP profile.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Set the interval for sending Pdelay_Req messages.

ptp pdelay-req-interval interval

By default, the interval argument value is 0 and the interval for sending peer delay request messages is 1 (20) second.

As a best practice, set the interval argument to a value in the range of ptp syn-interval interval to ptp syn-interval interval plus 5 for the SMPTE ST 2059-2 or AES67-2015 PTP profile.

Setting the interval for sending Sync messages

About this task

This task allows you to configure the interval at which the master node sends Sync messages to the member nodes. You must configure this task on the master node.

About this task

This task allows you to configure the interval at which the master node sends Sync messages to the member nodes. The configuration of the interval depends on the PTP profile in the PTP domain.

· PTP profile other than ITU-T G.8275.2, or ITU-T G.8275.2 PTP profile not using unicast negotiation—You must configure this task on the master node.

· ITU-T G.8275.2 PTP profile using unicast negotiation—You must configure this task on the request-port of the client. The request-port uses the configured interval to negotiate with the grant-port on the server for the interval at which the grant-port sends Sync messages to the client. If the negotiation succeeds, the grant-port sends Sync messages at the configured interval to the client. If the negotiation fails, the grant-port does not send Sync messages to the client.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Set the interval for sending Sync messages.

ptp syn-interval interval

The default settings vary by PTP profile.

¡ IEEE 1588 version 2—The interval argument value is 0 and the interval for sending Sync messages is 1 (20) second.

¡ IEEE 802.1AS, AES67-2015, or SMPTE ST 2059-2—The interval argument value is –3 and the interval for sending Sync messages is 1/8 (2-3) seconds.

¡ ITU-T G.8275.1 or ITU-T G.8275.2—The interval argument value is –4 and the interval for sending Sync messages is 1/16 (2-4) seconds.

Setting the minimum interval for sending Delay_Req messages

About this task

When receiving a Sync or Follow_Up message, an interface can send Delay_Req messages only when the minimum interval is reached. This task allows you to set the minimum interval for sending Delay_Req messages.

Restrictions and guidelines

This setting is not available for the IEEE 802.1AS PTP profile.

In PTP multicast transport mode, this setting takes effect only when configured on the master clock. The master clock sends the value to a member clock through PTP messages to control the interval for the member clock to send Delay_Req messages. To view the interval, execute the display ptp interface command on the member clock.

In PTP unicast transport mode, this setting takes effect when configured on member clocks. It does not take effect when configured on the master clock.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Set the minimum interval for sending Delay_Req messages.

ptp min-delayreq-interval interval

For the IEEE 1588 version 2, SMPTE ST 2059-2, or AES67-2015 PTP profile, the value of the interval argument is 0 and the minimum interval for sending delay request messages is 1 (20) second by default.

When the PTP profile is ITU-T G.8275.1 or ITU-T G.8275.2, the value of the interval argument is –4 and the minimum interval for sending delay request messages is 1/16 (2-4) seconds by default.

Setting the interval for sending Delay-Resp messages

About this task

This task, configured on a request-port, specifies the interval at which the grant-port sends Delay_resp messages to the request-port. After receiving a Delay_req message from a request port, the grant-port responds by sending a Delay_resp message and starts a timer defined by this command. The grant-port will not send another Delay_resp message until it receives a Delay_req message after the timer expires.

Restrictions and guidelines

This task is available only for the ITU-T G.8275.2 PTP profile and is configured on request-ports.

Procedure

1. Enter system view.

system-view

2. Enter Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Set the interval for sending Delay_resp messages.

ptp delay-resp-interval interval

By default, the value of the interval argument is –4 and the minimum interval for sending Delay_resp messages is 1/16 (2-4) seconds.

Configuring parameters for PTP messages

Specifying the IPv4 UDP transport protocol for PTP messages

About this task

PTP messages can be encapsulated in IEEE 802.3/Ethernet packets or UDP packets.

Restrictions and guidelines

The IEEE 802.1AS PTP profile supports only IEEE 802.3/Ethernet transport of PTP messages and does not support this task.

The SMPTE ST 2059-2, AES67-2015, and ITU-T G.8275.2 PTP profiles support only UDP transport of PTP messages and do not support this task.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Configure the IPv4 UDP transport protocol for PTP messages.

ptp transport-protocol udp

The IEEE 1588 version 2, IEEE 802.1AS, and ITU-T G.8275.1 PTP profiles support IEEE 802.3/Ethernet transport of PTP messages.

The SMPTE ST 2059-2, AES67-2015, and ITU-T G.8275.2 PTP profiles support IPv4 UDP transport of PTP messages.

Configuring a source IP address for multicast PTP messages transmitted over IPv4 UDP

About this task

To transport multicast PTP messages over IPv4 UDP, you must configure a source IP address for the messages.

Restrictions and guidelines

If both a source IP address for multicast PTP messages transmitted over IPv4 UDP and a destination address for unicast PTP messages transmitted over IPv4 UDP are configured, the system unicasts the messages.

This task is not available for the IEEE 802.1AS, ITU-T G.8275.1, or ITU-T G.8275.2 PTP profile.

Procedure

1. Enter system view.

system-view

2. Configure a source IP address for multicast PTP messages transmitted over IPv4 UDP.

ptp source ip-address [ vpn-instance vpn-instance-name ]

By default, no source IP address is configured for multicast PTP messages transmitted over IPv4 UDP.

Configuring a destination IP address for unicast PTP messages transmitted over IPv4 UDP

About this task

To transport unicast PTP messages over IPv4 UDP, you must configure a destination IP address for the messages.

Restrictions and guidelines

If both a source IP address for multicast PTP messages transmitted over UDP and a destination address for unicast PTP messages transmitted over UDP are configured, the system unicasts the messages.

This task is not available for the IEEE 802.1AS or ITU-T G.8275.1 PTP profile.

You must configure this task when the PTP profile is ITU-T G.8275.2.

Prerequisites

Configure an IP address for the current interface, and make sure the interface and the peer PTP interface can reach each other.

Procedure

1. Enter system view.

system-view

2. Enter Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Configure a destination IP address for unicast PTP messages transmitted over IPv4 UDP.

ptp unicast-destination ip-address

By default, no destination IP address is configured for unicast PTP messages transmitted over IPv4 UDP.

Configuring the MAC address for non-Pdelay messages

About this task

Pdelay messages include Pdelay_Req, Pdelay_Resp, and Pdelay_Resp_Follow_Up messages. The destination MAC address of Pdelay messages is 0180-C200-000E by default, which cannot be modified. The destination MAC address of non-Pdelay messages is either 0180-C200-000E or 011B-1900-0000.

Restrictions and guidelines

This feature takes effect only when PTP messages are encapsulated in IEEE 802.3/Ethernet packets.

This task is not available for the IEEE 802.1AS, SMPTE ST 2059-2, or ITU-T G.8275.2 PTP profile.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Configure the destination MAC address for non-Pdelay messages.

ptp destination-mac mac-address

The default destination MAC address is 011B-1900-0000.

Setting a DSCP value for PTP messages transmitted over UDP

About this task

The DSCP value determines the sending precedence of PTP messages transmitted over UDP.

Restrictions and guidelines

This task is not available for the IEEE 802.1AS or ITU-T G.8275.1 PTP profile.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Set a DSCP value for PTP messages transmitted over IPv4 UDP.

ptp dscp dscp

By default, the DSCP value is 56.

Specifying a VLAN tag for PTP messages

About this task

Perform this task to configure the VLAN ID and the 802.1p precedence in the VLAN tag carried by PTP messages.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

3. Specify a VLAN tag for PTP messages.

ptp vlan vlan-id [ dot1p dot1p-value ]

By default, PTP messages do not have a VLAN tag.

Disabling PTP path tracing

About this task

PTP path tracing traces the clock nodes that the clock signals traverse from the GM to the device. The system can obtain complete path tracing information only when all clock nodes on the path are enabled with PTP path tracing. If a device on the path does not support PTP path tracing, disable this feature to prevent PTP intercommunication issues.

Procedure

1. Enter system view.

system-view

2. Disable PTP path tracing.

ptp path-trace disable

By default, PTP path tracing is enabled.

Specifying the maximum number of removed steps (clock nodes) from the GM to the device

About this task

If the number of removed steps from the GM to the device on the PTP synchronization path is too large, the time synchronization accuracy will decrease. After you specify the maximum number of removed steps from the GM to the device, the device cannot synchronize time through PTP if the number of the removed steps exceeds the maximum value.

Procedure

1. Enter system view.

system-view

2. Specify the maximum number of removed steps from the GM to the device.

ptp max-steps-removed step-removed-value

By default, the maximum number of removed steps from the GM to the device is 255.

Enabling the device to notify the downstream nodes of its time synchronization state

About this task

The task enables the device to notify its downstream nodes of its time synchronization state.

By default, the device transfers only the locked and unlocked status of the upstream node to the downstream nodes, and does not transfer its locked or unlocked status to the downstream nodes.

After this task is configured, the device notifies the downstream nodes of its locked and unlocked status through the synchronizationUncertain flag in the announce messages. The downstream nodes do not synchronize to the device when they receive information that the device time is unlocked and synchronize to the device when they receive information that the device time is locked.

Restrictions and guidelines

This task is available only for the IEEE 1588 version 2 and ITU-T G.8275.1 PTP profiles.

Procedure

1. Enter system view.

system-view

2. Enable the device to notify the downstream nodes of its time synchronization state.

ptp sync-uncertain enable

By default, the device does not notify the downstream nodes of its time synchronization state.

Adjusting and correcting clock synchronization

Setting the delay correction value

About this task

PTP performs time synchronization based on the assumption that the delays in sending and receiving messages are the same. However, this is not practical. If you know the offset between the delays in sending and receiving messages, you can set the delay correction value for more accurate time synchronization.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Set a delay correction value.

ptp asymmetry-correction { minus | plus } value

The default is 0 nanoseconds. Delay correction is not performed.

Calculating the TAI based on the UTC time

About this task

International Atomic Time (TAI) is a high-precision atomic coordinate time scale. Coordinated Universal Time (UTC) is based on TAI and adjusted by leap seconds for synchronization with astronomical time.

UTC is constantly compared with UT1 (astronomical time, reflecting the earth's rotation). The International Bureau of Weights and Measures (BIPM) will notify to add or subtract one second from the UTC time scale at the last minute on a specific date (typically June 30 or December 31) to ensure that the difference between UTC and UT1 is within one second.

The BIPM publishes the difference between UTC and TAI periodically. Till now, UTC is 37 seconds behind TAI.

Internet devices typically use the UTC time. To provide more accurate time, PTP also uses TAI. If the device acts as a subordinate clock node, it uses the UTC time and TAI time of the clock reference. If the device acts as the clock reference, it will calculate the TAI time based on the UTC time, and synchronize the UTC and TAI time to the subordinate clocks. This task is used to calculate the TAI time based on the UTC time.

TAI = UTC + cumulative offset. To get the correct TAI time from the UTC time:

· Set the accurate UTC time on the device.

· Use the ptp utc offset command to set the cumulative offset of UTC relative to TAI as published by BIPM. This command takes effect immediately.

· If the BIPM notifies to add or subtract one second from the UTC time scale on a specific data after you use the ptp utc offset command to configure the cumulative offset of TAI relative to UTC, use the ptp utc { leap59-date | leap61-date } date command to change the UTC time. The TAI time will be changed accordingly.

Restrictions and guidelines

This setting takes effect only when it is configured on the master clock node and the local clock of the master clock node is the GM.

Configure this feature on both the master and member nodes for the new master clock to provide accurate TAI time after a master/member node switchover.

Procedure

1. Enter system view.

system-view

2. Set the cumulative offset of UTC relative to TAI.

ptp utc offset utc-offset

The default is 0 seconds.

3. Add or subtract one second from the UTC time scale at the last minute on the specified date.

ptp utc { leap59-date | leap61-date } date

By default, no second is added or subtracted from the UTC time.

Configuring ToD input or output

About this task

To use a ToD clock, you must configure ToD input or output:

· ToD input—The device obtains clock signals from an external ToD clock and synchronizes ToD to all cards on the device.

· ToD output—The device operates as a ToD clock to synchronize ToD to other devices in the PTP network.

To implement more accurate time synchronization, you can specify a delay correction value.

When the device connects to a ToD clock source correctly and is configured with this setting

Restrictions and guidelines

The device automatically deletes the ToD clock configuration if all PTP domain configurations are deleted.

Procedure

1. Enter system view.

system-view

2. Configure ToD input or output.

ptp { tod0 | tod1 } { input [ delay input-delay-time ] | output [ delay output-delay-time ] }

The default settings for this command depend on the device model.

Setting clock source parameters

1. Enter system view.

system-view

2. Set clock source parameters. Choose the option to configure as needed:

¡ ptp clock-source local { accuracy acc-value | class class-value | time-source ts-value }

¡ ptp clock-source { tod0 | tod1 } { accuracy acc-value | class class-value | time-source ts-value | grandmaster-clockid clock-id | offsetscaled-logvariance value }

The default settings for clock source parameters vary by PTP profile and PTP technical standard.

· The clock ID of a GM clock is 000000-0000-000000.

· ITU-T G.8275.1 PTP profile

¡ T-TSC clock node type

- Local clock source—The accuracy value is 254, the time class value is 255, the offset (log variance) value is 65535, and the time source value is 160. The four values are fixed, not configurable.

- ToD clock source—The accuracy value is 254, the time class value is 255, the offset (log variance) value is 65535, and the time source value is 32.

¡ T-BC or T-TC clock node type

The default PTP technical standard is used.

- Local clock source—The accuracy value and the time class value depend on the device model. The offset (log variance) value is 65535 and the time source value is 160. The offset (log variance) value is not configurable.

- ToD clock source—The accuracy value is 32, the time class value is 6, the offset (log variance) value is 65535, and the time source value is 32.

· IEEE 1588 version 2 PTP profile

¡ Local clock source—The accuracy value and the time class value depend on the device model. The offset (log variance) value is 65535 and the time source value is 160. The offset (log variance) value not configurable.

¡ ToD clock source—The accuracy value is 32, the time class value is 6, the offset (log variance) is 65535, and the time source value is 32.

· IEEE 802.1AS PTP profile

¡ Local clock source—The accuracy value, the time class value, and the offset (log variance) value depend on the device model. The time source value is 160.

¡ ToD clock source—The accuracy value is 32, the time class value is 6, the offset (log variance) is 16640, and the time source value is 32.

· ITU-T G.8275.2 PTP profile

¡ T-TSC-P clock node type

- Local clock source—The accuracy value is 254, the time class value is 255, the offset (log variance) value is 65535, and the time source value is 160. The four values are not configurable.

- ToD clock source—The accuracy value is 254, the time class value is 255, the offset (log variance) value is 65535, and the time source value is 32.

¡ T-BC-P clock node type

- ToD clock source—The accuracy value is 32, the time class value is 6, the offset (log variance) value is 65535, and the time source value is 32.

Configuring a priority for a clock

Configuring a priority for a clock (IEEE 1588 version 2, SMPTE ST 2059-2, AES67-2015, and IEEE 802.1AS)

About this task

Priorities for clocks are used to elect the GM. The smaller the priority value, the higher the priority.

Procedure

1. Enter system view.

system-view

2. Configure the priority for the specified clock for GM election through BMC.

ptp priority clock-source { local | tod0 | tod1 } { priority1 priority1 | priority2 priority2 }

The default value varies by PTP profile:

¡ IEEE 1588 version 2, SMPTE ST 2059-2, or AES67-2015—The priority 1 and priority 2 values are both 128.

¡ IEEE 802.1AS—The priority 1 value is 246 and the priority 2 value is 248.

Configuring a priority for a clock (ITU-T G.8275.1 and ITU-T G.8275.2)

About this task

Under the ITU-T G.8275.1 or ITU-T G.8275.2 PTP profile, you can configure priorities for the local clock node and the peer clock node.

Priorities for clocks affect the GM election. The smaller the priority value, the higher the priority.

Restrictions and guidelines

This task is available only under the ITU-T G.8275.1 and ITU-T G.8275.2 PTP profiles.

Configuring priorities for the local clock node

1. Enter system view.

system-view

2. Configure the priority for a clock.

ptp priority clock-source { local | tod0 | tod1 } { priority2 priority2 | local-priority local-priority }

By default, the priority 2 value is 128 for T-BC, T-TC, and T-BC-P clock nodes and 255 for T-TSC and T-TSC-P clock nodes. The local priority value is 128.

Configuring a priority for the peer clock node

An announce message does not carry the local priority of the clock node. Each PTP interface on a clock node has a local priority. You can use the ptp local-priority command to configure a local priority for a PTP interface. This priority will be used as the local priority of the peer node in BMC selection and is one of the factors that determine whether the peer node can be elected as the GM.

To configure a priority for the peer clock node:

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view or Layer 3 Ethernet interface view.

interface interface-type interface-number

3. Configure a priority for the peer clock node.

ptp local-priority local-priority

By default, the clock priority of the peer clock node is 128.

Configuring PTP logging

About this task

PTP logs help monitor the clock source status. The following PTP logs are available:

· PTP log that indicates a lower time class

Each PTP clock source has a class value. For a ToD clock source, you can set its class value by using the ptp clock-source command. The higher the value, the lower the class. When the class value of the clock source crosses the class threshold, the system outputs a log for notification.

· PTP log that indicates a higher time offset between the external reference clock and the PTP clock

If the device uses an external reference clock, it periodically calculates the time offset between the external reference clock and the PTP clock. When the offset exceeds the threshold, the device outputs a log for notification

· PTP logs that indicate a higher time-offset-sum peak-to-peak value

The PTP module calculates the time-offset-sum peak-to-peak value at specific intervals and compares the value with the threshold configured by this command. If the value is larger than the threshold, the system outputs a log for notification.

· PTP logs that indicate the time-locked or time-unlocked state

When the time offset of the PTP reference clock crosses the PTP time locking threshold, the PTP time is put into unlocked state. The system outputs a time-unlocked log for notification. When the time offset of the PTP reference clock drops to or below the PTP time locking threshold, the PTP time is put into locked state. The system outputs a time-locked log for notification.

Restrictions and guidelines

Only the IEEE 1588 version 2, ITU-T G.8275.1, and ITU-T G.8275.2 PTP profiles support this task.

Procedure

1. Enter system view.

system-view

2. Configure the class threshold for the clock source.

ptp alarm-threshold clock-source-class class-value

By default, the class threshold for the clock source is 6.

3. Configure the time-offset threshold between the external reference clock and the PTP clock.

ptp alarm-threshold time-offset time-offset-value

By default, the time-offset threshold is 500 ns between the external reference clock and the PTP clock.

4. Set the time-offset-sum peak-to-peak threshold.

ptp alarm-threshold time-offset-sum pk-pk threshold-value

By default, the time-offset-sum peak-to-peak threshold is 500 ns.

Display and maintenance commands for PTP

Execute display commands in any view and the reset command in user view.

Task	Command
Display PTP clock information.	display ptp clock
Display the delay correction history.	display ptp corrections
Display information about foreign master nodes.	display ptp foreign-masters-record [ interface interface-type interface-number ]
Display PTP information on an interface.	display ptp interface [ interface-type interface-number \| brief ]
Display brief PTP information on all interfaces.	display ptp interface brief
Display parent node information for the PTP device.	display ptp parent
Display PTP statistics.	display ptp statistics [ interface interface-type interface-number ]
Display PTP clock time properties.	display ptp time-property
Clear PTP statistics.	reset ptp statistics [ interface interface-type interface-number ]

‌

PTP configuration examples

Example: Configuring PTP (IEEE 1588 version 2, IEEE 802.3/Ethernet transport, multicast transmission)

Network configuration

As shown in Figure 6, a PTP domain contains Device A, Device B, and Device C.

· Configure all devices to use the IEEE 1588 version 2 PTP profile.

· Configure PTP messages to be encapsulated in IEEE 802.3/Ethernet packets.

· Specify the OC clock node type for Device A and Device C, and E2ETC clock node type for Device B. All clock nodes elect a GM through BMC based on their respective default GM attributes.

· Use the default Request_Response delay measurement mechanism on Device A and Device C.

Figure 6 Network diagram

‌

Procedure

1. Configure Device A:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceA> system-view

[DeviceA] ptp profile 1588v2

# Specify the OC clock node type.

[DeviceA] ptp mode oc

# Create a PTP domain.

[DeviceA] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceA] clock protocol ptp

# Enable PTP on Twenty-FiveGigE 1/0/1.

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] ptp enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

2. Configure Device B:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceB> system-view

[DeviceB] ptp profile 1588v2

# Specify the E2ETC clock node type.

[DeviceB] ptp mode e2etc

# Create a PTP domain.

[DeviceB] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceB] clock protocol ptp

# Enable PTP on Twenty-FiveGigE 1/0/1.

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] ptp enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

# Enable PTP on Twenty-FiveGigE 1/0/2.

[DeviceB] interface twenty-fivegige 1/0/2

[DeviceB-Twenty-FiveGigE1/0/2] ptp enable

[DeviceB-Twenty-FiveGigE1/0/2] quit

3. Configure Device C:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceC> system-view

[DeviceC] ptp profile 1588v2

# Specify the OC clock node type.

[DeviceC] ptp mode oc

# Create a PTP domain.

[DeviceC] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceC] clock protocol ptp

# Enable PTP on Twenty-FiveGigE 1/0/1.

[DeviceC] interface twenty-fivegige 1/0/1

[DeviceC-Twenty-FiveGigE1/0/1] ptp enable

[DeviceC-Twenty-FiveGigE1/0/1] quit

Verifying the configuration

When the network is stable, perform the following tasks to verify that Device A is elected as the GM, Twenty-FiveGigE1/0/1 on Device A is the master port, and Device B has synchronized to Device A:

· Use the display ptp clock command to display PTP clock information.

· Use the display ptp interface brief command to display brief PTP running information for all PTP interfaces.

# Display PTP clock information on Device A.

[DeviceA] display ptp clock

PTP profile : IEEE 1588 Version 2

PTP mode : OC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0000

Clock type : Local

Clock domain : 0

Number of PTP ports : 1

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 0 (ns)

Mean path delay : 0 (ns)

Steps removed : 0

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device A.

[DeviceA] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Master E2E Two 0 WGE1/0/1

# Display PTP clock information on Device B.

[DeviceB] display ptp clock

PTP profile : IEEE 1588 Version 2

PTP mode : E2ETC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0001

Clock type : Local

Clock domain : 0

Number of PTP ports : 2

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : N/A

Mean path delay : N/A

Steps removed : N/A

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device B.

[DeviceB] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

N/A E2E Two 0 WGE1/0/1

N/A E2E Two 0 WGE1/0/2

Example: Configuring PTP (IEEE 1588 version 2, IPv4 UDP transport, multicast transmission)

Network configuration

As shown in Figure 7, a PTP domain contains Device A, Device B, and Device C.

· Configure all devices to use the IEEE 1588 version 2 PTP profile.

· Configure the source IP address for multicast PTP messages transmitted over IPv4 UDP.

· Specify the OC clock node type for Device A and Device C, and the P2PTC clock node type for Device B. All clock nodes elect a GM through BMC based on their respective default GM attributes.

· Configure the peer delay measurement mechanism (p2p) for Device A and Device C.

Figure 7 Network diagram

‌

Procedure

1. Configure Device A:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceA> system-view

[DeviceA] ptp profile 1588v2

# Specify the OC clock node type.

[DeviceA] ptp mode oc

# Create a PTP domain.

[DeviceA] ptp domain 0

# Configure the source IP address for multicast PTP messages transmitted over IPv4 UDP.

[DeviceA] ptp source 10.10.1.1

# Specify PTP for obtaining the time.

[DeviceA] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, specify the IPv4 UDP transport protocol for PTP messages, specify the delay measurement mechanism as p2p, and enable PTP.

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] ptp transport-protocol udp [DeviceA-Twenty-FiveGigE1/0/1] ptp delay-mechanism p2p

[DeviceA-Twenty-FiveGigE1/0/1] ptp enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

2. Configure Device B:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceB> system-view

[DeviceB] ptp profile 1588v2

# Specify the P2PTC clock node type.

[DeviceB] ptp mode p2ptc

# Create a PTP domain.

[DeviceB] ptp domain 0

# Configure the source IP address for multicast PTP messages transmitted over UDP.

[DeviceB] ptp source 10.10.2.1

# Specify PTP for obtaining the time.

[DeviceB] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, specify the IPv4 UDP transport protocol for PTP messages and enable PTP.

[DeviceB] interface twenty-fivegige 1/0/1

DeviceB-Twenty-FiveGigE1/0/1] ptp transport-protocol udp

[DeviceB-Twenty-FiveGigE1/0/1] ptp enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

# On Twenty-FiveGigE 1/0/2, specify the IPv4 UDP transport protocol for PTP messages and enable PTP.

[DeviceB] interface twenty-fivegige 1/0/2

[DeviceB-Twenty-FiveGigE1/0/2] ptp transport-protocol udp

[DeviceB-Twenty-FiveGigE1/0/2] ptp enable

[DeviceB-Twenty-FiveGigE1/0/2] quit

3. Configure Device C:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceC> system-view

[DeviceC] ptp profile 1588v2

# Specify the OC clock node type.

[DeviceC] ptp mode oc

# Create a PTP domain.

[DeviceC] ptp domain 0

# Configure the source IP address for multicast PTP messages transmitted over UDP.

[DeviceC] ptp source 10.10.3.1

# Specify PTP for obtaining the time.

[DeviceC] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, specify the IPv4 UDP transport protocol for PTP messages, specify the delay measurement mechanism as p2p, and enable PTP.

[DeviceC] interface twenty-fivegige 1/0/1

[DeviceC-Twenty-FiveGigE1/0/1] ptp transport-protocol udp [DeviceC-Twenty-FiveGigE1/0/1] ptp delay-mechanism p2p

[DeviceC-Twenty-FiveGigE1/0/1] ptp enable

[DeviceC-Twenty-FiveGigE1/0/1] quit

Verifying the configuration

When the network is stable, perform the following tasks to verify that Device A is elected as the GM, Twenty-FiveGigE1/0/1 on Device A is the master port, and Device B has synchronized to Device A:

· Use the display ptp clock command to display PTP clock information.

· Use the display ptp interface brief command to display brief PTP running information for all PTP interfaces.

# Display PTP clock information on Device A.

[DeviceA] display ptp clock

PTP profile : IEEE 1588 Version 2

PTP mode : OC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0000

Clock type : Local

Clock domain : 0

Number of PTP ports : 1

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 0 (ns)

Mean path delay : 0 (ns)

Steps removed : 0

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device A.

[DeviceA] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Master P2P Two 0 WGE1/0/1

# Display PTP clock information on Device B.

[DeviceB] display ptp clock

PTP profile : IEEE 1588 Version 2

PTP mode : P2PTC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0001

Clock type : Local

Clock domain : 0

Number of PTP ports : 2

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : N/A

Mean path delay : N/A

Steps removed : N/A

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device B.

[DeviceB] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

N/A P2P Two 0 WGE1/0/1

N/A P2P Two 0 WGE1/0/2

Example: Configuring PTP (IEEE 1588 version 2, IPv4 UDP transport, unicast transmission)

Network configuration

As shown in Figure 8, configure PTP (IEEE 1588 version 2, IPv4 UDP transport, unicast transmission) to enable Device A, Device B, Device C, and the base station to synchronize the time with the ToD clock source.

· Specify the IEEE 1588 version 2 PTP profile and unicast IPv4 UDP transport of PTP messages for Device A, Device B, and Device C.

· Assign Device A, Device B, Device C, and the base station to PTP domain 0. Specify the BC clock node type for Device A, Device B, and Device C.

· Connect Device A to the ToD clock source and Device C to the base station.

· Use the default Request_Response delay measurement mechanism on all clock nodes in the PTP domain.

Figure 8 Network diagram

‌

Procedure

1. Assign IP addresses to the interfaces, and make sure the devices can reach each other, as shown in Figure 8. (Details not shown.)

2. Configure Device A:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceA> system-view

[DeviceA] ptp profile 1588v2

# Specify the BC clock node type.

[DeviceA] ptp mode bc

# Create a PTP domain.

[DeviceA] ptp domain 0

# Configure the delay time correction as 1000 nanoseconds for receiving ToD 0 clock signals.

[DeviceA] ptp tod0 input delay 1000

# Set priority 1 to 0 for the ToD 0 clock.

[DeviceA] ptp priority clock-source tod0 priority1 0

# On Twenty-FiveGigE 1/0/1, configure the destination IP address for unicast PTP messages transmitted over IPv4 UDP, and enable PTP.

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] ptp transport-protocol udp

[DeviceA-Twenty-FiveGigE1/0/1] ptp unicast-destination 10.10.10.2

[DeviceA-Twenty-FiveGigE1/0/1] ptp enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

3. Configure Device B:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceB> system-view

[DeviceB] ptp profile 1588v2

# Specify the BC clock node type.

[DeviceB] ptp mode bc

# Create a PTP domain.

[DeviceB] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceB] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, configure the destination IP address for unicast PTP messages transmitted over IPv4 UDP, and enable PTP.

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] ptp transport-protocol udp

[DeviceB-Twenty-FiveGigE1/0/1] ptp unicast-destination 10.10.10.1

[DeviceB-Twenty-FiveGigE1/0/1] ptp enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

# On Twenty-FiveGigE 1/0/2, configure the destination IP address for unicast PTP messages transmitted over IPv4 UDP, and enable PTP.

[DeviceB] interface twenty-fivegige 1/0/2

[DeviceB-Twenty-FiveGigE1/0/2] ptp transport-protocol udp

[DeviceB-Twenty-FiveGigE1/0/2] ptp unicast-destination 11.10.10.1

[DeviceB-Twenty-FiveGigE1/0/2] ptp enable

[DeviceB-Twenty-FiveGigE1/0/2] quit

4. Configure Device C:

# Specify the IEEE 1588 version 2 PTP profile.

<DeviceC> system-view

[DeviceC] ptp profile 1588v2

# Specify the BC clock node type.

[DeviceC] ptp mode bc

# Create a PTP domain.

[DeviceC] ptp domain 0

# Configure the delay time correction as 100 nanoseconds for sending ToD 0 clock signals.

[DeviceC] ptp tod0 output delay 100

# Specify PTP for obtaining the time.

[DeviceC] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, configure the destination IP address for unicast PTP messages transmitted over IPv4 UDP, and enable PTP.

[DeviceC] interface twenty-fivegige 1/0/1

[DeviceC-Twenty-FiveGigE1/0/1] ptp transport-protocol udp

[DeviceC-Twenty-FiveGigE1/0/1] ptp unicast-destination 11.10.10.2

[DeviceC-Twenty-FiveGigE1/0/1] ptp enable

[DeviceC-Twenty-FiveGigE1/0/1] quit

# On Twenty-FiveGigE1/0/2, specify IPv4 UDP transport of PTP messages, configure the destination IP address for unicast PTP messages, and enable PTP.

[DeviceC] interface twenty-fivegige 1/0/2

[DeviceC-Twenty-FiveGigE1/0/2] ptp transport-protocol udp

[DeviceC-Twenty-FiveGigE1/0/2] ptp unicast-destination 12.10.10.1

[DeviceC-Twenty-FiveGigE1/0/2] ptp enable

[DeviceC-Twenty-FiveGigE1/0/2] quit

5. Configure the base station.

# Specify PTP domain 0.

# Specify IPv4 UDP transport of PTP messages.

# Set the destination IP address of unicast PTP messages to 12.10.10.2.

# Specify the Request_Response delay measurement mechanism.

For more information, see the configuration guide for the base station.

Verifying the configuration

When the network is stable, perform the following tasks:

· Use the display ptp clock command to display PTP clock information.

· Use the display ptp interface brief command to display brief PTP running information for all PTP interfaces.

# Display PTP clock information on Device A.

[DeviceA] display ptp clock

PTP profile : IEEE 1588 Version 2

PTP mode : BC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0000

Clock type : ToD0

ToD direction : In

ToD delay time : 1000 (ns)

Clock domain : 0

Number of PTP ports : 1

Priority1 : 0

Priority2 : 128

Clock quality :

Class : 6

Accuracy : 32

Offset (log variance) : 65535

Offset from master : 0 (ns)

Mean path delay : 0 (ns)

Steps removed : 0

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Active 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device A.

[DeviceA] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Master E2E Two 0 WGE1/0/1

# Display PTP clock information on Device C.

[DeviceC] display ptp clock

PTP profile : IEEE 1588 Version 2

PTP mode : BC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0001

Clock type : Local

Clock domain : 0

Number of PTP ports : 2

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 50 (ns)

Mean path delay : 6800 (ns)

Steps removed : 2

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device C.

[DeviceC] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Slave E2E Two 0 WGE1/0/1

Master E2E Two 0 WGE1/0/2

Example: Configuring PTP (IEEE 802.1AS, IEEE 802.3/Ethernet transport, multicast transmission)

Network configuration

As shown in Figure 9, a PTP domain contains Device A, Device B, and Device C.

· Configure all devices to use the IEEE 802.1AS PTP profile.

· Specify the OC clock node type for Device A and Device C, and the P2PTC clock node type for Device B. All clock nodes elect a GM through BMC based on their respective default GM attributes.

· Use the default peer delay measurement mechanism on all clock nodes in the PTP domain.

Figure 9 Network diagram

‌

Procedure

IMPORTANT:

The IEEE 802.1AS PTP profile transports PTP messages over IEEE 802.3/Ethernet rather than IPv4 UDP and in multicast rather than unicast mode.

1. Configure Device A:

# Specify the IEEE 802.1AS PTP profile.

<DeviceA> system-view

[DeviceA] ptp profile 802.1AS

# Specify the OC clock node type.

[DeviceA] ptp mode oc

# Create a PTP domain.

[DeviceA] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceA] clock protocol ptp

# Enable PTP on Twenty-FiveGigE 1/0/1.

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] ptp enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

2. Configure Device B:

# Specify the IEEE 802.1AS PTP profile.

<DeviceB> system-view

[DeviceB] ptp profile 802.1AS

# Specify the P2PTC clock node type.

[DeviceB] ptp mode p2ptc

# Create a PTP domain.

[DeviceB] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceB] clock protocol ptp

# Enable PTP on Twenty-FiveGigE 1/0/1.

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] ptp enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

# Enable PTP on Twenty-FiveGigE 1/0/2.

[DeviceB] interface twenty-fivegige 1/0/2

[DeviceB-Twenty-FiveGigE1/0/2] ptp enable

[DeviceB-Twenty-FiveGigE1/0/2] quit

3. Configure Device C:

# Specify the IEEE 1588 802.1AS PTP profile.

<DeviceC> system-view

[DeviceC] ptp profile 802.1AS

# Specify the OC clock node type.

[DeviceC] ptp mode oc

# Create a PTP domain.

[DeviceC] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceC] clock protocol ptp

# Enable PTP on Twenty-FiveGigE 1/0/1.

[DeviceC] interface twenty-fivegige 1/0/1

[DeviceC-Twenty-FiveGigE1/0/1] ptp enable

[DeviceC-Twenty-FiveGigE1/0/1] quit

Verifying the configuration

When the network is stable, perform the following tasks to verify that Device A is elected as the GM, Twenty-FiveGigE1/0/1 on Device A is the master port, and Device B has synchronized to Device A:

· Use the display ptp clock command to display PTP clock information.

· Use the display ptp interface brief command to display brief PTP running information for all PTP interfaces.

# Display PTP clock information on Device A.

[DeviceA] display ptp clock

PTP profile : IEEE 802.1AS

PTP mode : OC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0000

Clock type : Local

Clock domain : 0

Number of PTP ports : 1

Priority1 : 246

Priority2 : 248

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 16640

Offset from master : 0 (ns)

Mean path delay : 0 (ns)

Steps removed : 0

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device A.

[DeviceA] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Master P2P Two 0 WGE1/0/1

# Display PTP clock information on Device B.

[DeviceB] display ptp clock

PTP profile : IEEE 802.1AS

PTP mode : P2PTC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0001

Clock type : Local

Clock domain : 0

Number of PTP ports : 2

Priority1 : 246

Priority2 : 248

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 16640

Offset from master : N/A

Mean path delay : N/A

Steps removed : N/A

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device B.

[DeviceB] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

N/A P2P Two 0 WGE1/0/1

N/A P2P Two 0 WGE1/0/2

Example: Configuring PTP (SMPTE ST 2059-2, IPv4 UDP transport, multicast transmission)

Network configuration

As shown in Figure 10, Device A, Device B, and Device C are in a PTP domain. Configure PTP (SMPTE ST 2059-2, multicast transmission) on the three devices as follows for time synchronization:

· Configure the devices to use the SMPTE ST 2059-2 PTP profile.

· Configure the source IP address for multicast PTP messages transmitted over IPv4 UDP.

· Specify the OC clock node type for Device A and Device C, and the P2PTC clock node type for Device B. All clock nodes elect a GM through BMC based on their respective default GM attributes.

· Use the peer delay measurement mechanism on all clock nodes in the PTP domain.

Figure 10 Network diagram

‌

Procedure

IMPORTANT:

The SMPTE ST 2059-2 PTP profile transports PTP messages over IPv4 UDP rather than IEEE 802.3/Ethernet and in multicast rather than unicast mode.

1. Configure Device A:

# Specify the SMPTE ST 2059-2 PTP profile.

<DeviceA> system-view

[DeviceA] ptp profile st2059-2

# Specify the OC clock node type.

[DeviceA] ptp mode oc

# Create a PTP domain.

[DeviceA] ptp domain 0

# Configure the source IP address for multicast PTP messages transmitted over IPv4 UDP.

[DeviceA] ptp source 10.10.1.1

# Specify PTP for obtaining the time.

[DeviceA] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, specify the delay measurement mechanism as p2p and enable PTP.

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] ptp transport-protocol udp [DeviceA-Twenty-FiveGigE1/0/1] ptp delay-mechanism p2p

[DeviceA-Twenty-FiveGigE1/0/1] ptp enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

2. Configure Device B:

# Specify the SMPTE ST 2059-2 PTP profile.

<DeviceB> system-view

[DeviceB] ptp profile st2059-2

# Specify the P2PTC clock node type.

[DeviceB] ptp mode p2ptc

# Create a PTP domain.

[DeviceB] ptp domain 0

# Configure the source IP address for multicast PTP messages transmitted over IPv4 UDP.

[DeviceB] ptp source 10.10.2.1

# Specify PTP for obtaining the time.

[DeviceB] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, enable PTP.

[DeviceB] interface twenty-fivegige 1/0/1

DeviceB-Twenty-FiveGigE1/0/1] ptp transport-protocol udp

[DeviceB-Twenty-FiveGigE1/0/1] ptp enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

# On Twenty-FiveGigE 1/0/2, enable PTP.

[DeviceB] interface twenty-fivegige 1/0/2

[DeviceB-Twenty-FiveGigE1/0/2] ptp transport-protocol udp

[DeviceB-Twenty-FiveGigE1/0/2] ptp enable

[DeviceB-Twenty-FiveGigE1/0/2] quit

3. Configure Device C:

# Specify the SMPTE ST 2059-2 PTP profile.

<DeviceC> system-view

[DeviceC] ptp profile st2059-2

# Specify the OC clock node type.

[DeviceC] ptp mode oc

# Create a PTP domain.

[DeviceC] ptp domain 0

# Configure the source IP address for multicast PTP messages transmitted over IPv4 UDP.

[DeviceC] ptp source 10.10.3.1

# Specify PTP for obtaining the time.

[DeviceC] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, specify the delay measurement mechanism as p2p and enable PTP.

[DeviceC] interface twenty-fivegige 1/0/1

[DeviceC-Twenty-FiveGigE1/0/1] ptp delay-mechanism p2p

[DeviceC-Twenty-FiveGigE1/0/1] ptp enable

[DeviceC-Twenty-FiveGigE1/0/1] quit

Verifying the configuration

When the network is stable, perform the following tasks to verify the PTP configuration:

· Use the display ptp clock command to display PTP clock information.

· Use the display ptp interface brief command to display brief PTP running information for all PTP interfaces.

# Display PTP clock information on Device A.

[DeviceA] display ptp clock

PTP profile : SMPTE ST 2059-2

PTP mode : OC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0000

Clock type : Local

Clock domain : 0

Number of PTP ports : 1

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 106368539000 (ns)

Mean path delay : 2791000 (ns)

Steps removed : 1

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device A.

[DeviceA] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Master P2P Two 0 WGE1/0/1

# Display PTP clock information on Device B.

[DeviceB] display ptp clock

PTP profile : SMPTE ST 2059-2

PTP mode : P2PTC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0001

Clock type : Local

Clock domain : 0

Number of PTP ports : 2

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : N/A

Mean path delay : N/A

Steps removed : N/A

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all PTP interfaces on Device B.

[DeviceB] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

N/A P2P Two 0 WGE1/0/1

N/A P2P Two 0 WGE1/0/2

The output shows that Device A is elected as the GM and Twenty-FiveGigE1/0/1 on Device A is the master port.

Example: Configuring PTP (SMPTE ST 2059-2, IPv4 UDP transport, unicast transmission)

Network configuration

As shown in Figure 11, configure PTP (SMPTE ST 2059-2, IPv4 UDP transport, unicast transmission) to enable Device A, Device B, Device C, and the base station to synchronize time with the ToD clock source .

· Specify the SMPTE ST 2059-2 PTP profile and unicast IPv4 UDP transport of PTP messages for Device A, Device B, and Device C.

· Assign Device A, Device B, Device C, and the base station to PTP domain 0. Specify the BC clock node type for Device A, Device B, and Device C.

· Connect Device A to the ToD clock source and Device C to the base station.

· Use the default Request_Response delay measurement mechanism on all clock nodes in the PTP domain.

Figure 11 Network diagram

‌

Procedure

IMPORTANT:

The SMPTE ST 2059-2 PTP profile transports PTP messages over IPv4 UDP rather than IEEE 802.3/Ethernet and in multicast rather than unicast mode.

1. Assign IP addresses to the interfaces, and make sure the devices can reach each other, as shown in Figure 11. (Details not shown.)

2. Configure Device A:

# Specify the SMPTE ST 2059-2 PTP profile.

<DeviceA> system-view

[DeviceA] ptp profile st2059-2

# Specify the BC clock node type.

[DeviceA] ptp mode bc

# Create a PTP domain.

[DeviceA] ptp domain 0

# Configure the device to receive ToD 0 clock signals and set the delay correction value to 1000 nanoseconds.

[DeviceA] ptp tod0 input delay 1000

# Set priority 1 to 0 for the ToD 0 clock.

[DeviceA] ptp priority clock-source tod0 priority1 0

# On Twenty-FiveGigE 1/0/1, configure the destination IP address for unicast PTP messages and enable PTP. (The SMPTE ST 2059-2 PTP profile uses IPv4 UDP transport of PTP messages by default.)

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] ptp transport-protocol udp

[DeviceA-Twenty-FiveGigE1/0/1] ptp unicast-destination 10.10.10.2

[DeviceA-Twenty-FiveGigE1/0/1] ptp enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

3. Configure Device B:

# Specify the SMPTE ST 2059-2 PTP profile.

<DeviceB> system-view

[DeviceB] ptp profile st2059-2

# Specify the BC clock node type.

[DeviceB] ptp mode e2etc

# Create a PTP domain.

[DeviceB] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceA] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, configure the destination IP address for unicast PTP messages and enable PTP. (The SMPTE ST 2059-2 PTP profile uses IPv4 UDP transport of PTP messages by default.)

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] ptp unicast-destination 10.10.10.1

[DeviceB-Twenty-FiveGigE1/0/1] ptp enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

# On Twenty-FiveGigE 1/0/2, configure the destination IP address for unicast PTP messages and enable PTP. (The SMPTE ST 2059-2 PTP profile uses IPv4 UDP transport of PTP messages by default.)

[DeviceB] interface twenty-fivegige 1/0/2

[DeviceB-Twenty-FiveGigE1/0/2] ptp unicast-destination 11.10.10.1

[DeviceB-Twenty-FiveGigE1/0/2] ptp enable

[DeviceB-Twenty-FiveGigE1/0/2] quit

4. Configure Device C:

# Specify the SMPTE ST 2059-2 PTP profile.

<DeviceC> system-view

[DeviceC] ptp profile st2059-2

# Specify the BC clock node type.

[DeviceC] ptp mode bc

# Create a PTP domain.

[DeviceC] ptp domain 0

# Specify PTP for obtaining the time.

[DeviceC] clock protocol ptp

# On Twenty-FiveGigE 1/0/1, configure the destination IP address for unicast PTP messages and enable PTP.

[DeviceC] interface twenty-fivegige 1/0/1

[DeviceC-Twenty-FiveGigE1/0/1] ptp transport-protocol udp

[DeviceC-Twenty-FiveGigE1/0/1] ptp unicast-destination 11.10.10.2

[DeviceC-Twenty-FiveGigE1/0/1] ptp enable

[DeviceC-Twenty-FiveGigE1/0/1] quit

# On Twenty-FiveGigE1/0/2, configure the destination IP address for unicast PTP messages and enable PTP. (The SMPTE ST 2059-2 PTP profile uses IPv4 UDP transport of PTP messages by default.)

[DeviceC] interface twenty-fivegige 1/0/2

[DeviceC-Twenty-FiveGigE1/0/2] ptp unicast-destination 12.10.10.1

[DeviceC-Twenty-FiveGigE1/0/2] ptp enable

[DeviceC-Twenty-FiveGigE1/0/2] quit

5. Configure the base station.

# Specify PTP domain 0.

# Specify IPv4 UDP transport of PTP messages.

# Set the destination IP address of unicast PTP messages to 12.10.10.2.

# Specify the Request_Response delay measurement mechanism.

For more information, see the configuration guide for the base station.

Verifying the configuration

When the network is stable, perform the following tasks to verify the PTP configuration:

· Use the display ptp clock command to display PTP clock information.

· Use the display ptp interface brief command to display brief PTP running information.

# Display PTP clock information on Device A.

[DeviceA] display ptp clock

PTP profile : SMPTE ST 2059-2

PTP mode : BC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0000

Clock type : ToD0

ToD direction : In

ToD delay time : 1000 (ns)

Clock domain : 0

Number of PTP ports : 1

Priority1 : 0

Priority2 : 128

Clock quality :

Class : 6

Accuracy : 32

Offset (log variance) : 65535

Offset from master : 0 (ns)

Mean path delay : 0 (ns)

Steps removed : 0

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Active 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information on Device A.

[DeviceA] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Master E2E Two 0 WGE1/0/1

# Display PTP clock information on Device C.

[DeviceC] display ptp clock

PTP profile : SMPTE ST 2059-2

PTP mode : BC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 000FE2-FFFE-FF0001

Clock type : Local

Clock domain : 0

Number of PTP ports : 2

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 50 (ns)

Mean path delay : 6800 (ns)

Steps removed : 2

Local clock time : Sun Jan 15 20:57:29 2019

Clock source info:

Clock Pri1 Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information on Device C.

[DeviceC] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Slave E2E Two 0 WGE1/0/1

Master E2E Two 0 WGE1/0/2

Example: Configuring PTP (ITU-TG.8275.1, IEEE 802.3/Ethernet encapsulation, multicast transmission)

Network configuration

As shown in Figure 9, Device A and Device B are in a PTP domain.

· Specify the ITU-TG.8275.1 PTP profile for Device A and Device B.

· Specify the T-BC clock node type for Device A and T-TSC clock node type for Device B.

· Use the default Request_Response delay measurement mechanism on Device A and Device B.

Figure 12 Network diagram

‌

Procedure

IMPORTANT:

The ITU-TG.8275.1 PTP profile transports PTP messages over IEEE 802.3/Ethernet rather than IPv4 UDP and in multicast rather than unicast mode.

1. Configure Device A:

# Specify the ITU-T G.8275.1 PTP profile.

<DeviceA> system-view

[DeviceA] ptp profile g8275.1

# Specify a PTP domain.

[DeviceA] ptp domain 24

# Specify the T-BC clock node type.

[DeviceA] ptp mode t-bc

# Specify PTP for obtaining the time.

[DeviceA] clock protocol ptp

# Enable PTP on Twenty-FiveGigE 1/0/1.

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] ptp enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

2. Configure Device B:

# Specify the ITU-T G.8275.1 PTP profile.

<DeviceB> system-view

[DeviceB] ptp profile g8275.1

# Specify a PTP domain.

[DeviceB] ptp domain 24

# Specify the T-TSC clock node type.

[DeviceB] ptp mode t-tsc

# Specify PTP for obtaining the time.

[DeviceB] clock protocol ptp

# Enable PTP on Twenty-FiveGigE 1/0/1.

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] ptp enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

Verifying the configuration

When the network is stable, perform the following tasks:

· Use the display ptp clock command to display PTP clock information.

· Use the display ptp interface brief command to display brief PTP running information for all interfaces.

# Display PTP clock information on Device A.

[DeviceA] display ptp clock

PTP profile : ITU-T G.8275.1

PTP mode : T-BC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 24881D-FFFE-F20100

Clock type : Local

Clock domain : 24

Number of PTP ports : 1

Priority1 : 128

Priority2 : 128

Local priority : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 0 (ns)

Mean path delay : 0 (ns)

Steps removed : 0

Local clock time : Fri Dec 7 00:59:44 2019

Clock source info:

Clock LP Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

-------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 In Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information for all interfaces on Device A.

[DeviceA] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Master E2E Two 0 WGE1/0/1

# Display PTP clock information on Device B.

[DeviceB] display ptp clock

PTP profile : ITU-T G.8275.1

PTP mode : T-TSC

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 2461E3-FFFE-A20200

Clock type : Local

Clock domain : 24

Number of PTP ports : 1

Priority1 : 128

Priority2 : 255

Local priority : 128

Clock quality :

Class : 255

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 50 (ns)

Mean path delay : 5000 (ns)

Steps removed : 1

Local clock time : Fri Dec 7 14:52:54 2019

Clock source info:

Clock LP Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

-------------------------------------------------------------------

Local 128 255 254 255 160 N/A N/A 65535

ToD0 128 255 254 255 32 In Inactive 65535

ToD1 128 255 254 255 32 N/A Inactive 65535

# Display brief PTP running information for all interfaces on Device B.

[DeviceB] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Slave E2E Two 0 WGE1/0/1

The output shows that Device A is elected as the GM, and Twenty-FiveGigE1/0/1 on Device A is the master port.

Example: Configuring PTP (ITU-TG.8275.2, IPv4 UDP encapsulation, unicast transmission)

Network configuration

As shown in Figure 13, Device A and Device B are in a PTP domain. The switch is a Layer 2 switch that does not support PTP. Configure PTP (ITU-TG.8275.2, IPv4 UDP encapsulation, unicast transmission) to enable Device B to synchronize to Device A.

· Specify the ITU-TG.8275.2 PTP profile for Device A and Device B.

· Use the default Request_Response delay measurement mechanism on Device A and Device B.

Figure 13 Network diagram

‌

Prerequisites

Configure IP addresses and routing protocols for the devices. Make sure the devices are reachable to each other.

Procedure

IMPORTANT:

The ITU-T G.8275.2 PTP profile transports PTP messages over IPv4 UDP rather than IEEE 802.3/Ethernet and in unicast rather than multicast mode.

1. Configure IP address and routing settings. Make sure the devices are reachable to each other.

2. Configure Device A:

# Specify the ITU-T G.8275.2 PTP profile.

<DeviceA> system-view

[DeviceA] ptp profile g8275.2

# Specify the T-BC-P clock node type.

[DeviceA] ptp mode t-bc-p

# Specify a PTP domain.

[DeviceA] ptp domain 44

# Specify PTP for obtaining the time.

[DeviceA] clock protocol ptp

# Enable PTP and configure PTP parameters on Twenty-FiveGigE1/0/1.

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] ptp unicast-destination 1.1.1.2

[DeviceA-Twenty-FiveGigE1/0/1] ptp unicast-negotiate grant-port

[DeviceA-Twenty-FiveGigE1/0/1] ptp notslave disable

[DeviceA-Twenty-FiveGigE1/0/1] ptp enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

3. Configure Device B:

# Specify the ITU-T G.8275.2 PTP profile.

<DeviceB> system-view

[DeviceB] ptp profile g8275.2

# Specify the T-TSC-P clock node type.

[DeviceB] ptp mode t-tsc-p

# Specify a PTP domain.

[DeviceB] ptp domain 44

# Specify PTP for obtaining the time.

[DeviceB] clock protocol ptp

# Enable PTP on Twenty-FiveGigE1/0/1.

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] ptp unicast-destination 1.1.1.1

[DeviceB-Twenty-FiveGigE1/0/1] ptp unicast-negotiate request-port

[DeviceB-Twenty-FiveGigE1/0/1] ptp enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

Verifying the configuration

When the network is stable, perform the following tasks:

· Use the display ptp clock command to display PTP clock information.

· Use the display ptp interface brief command to display brief PTP running information for all interfaces.

# Display PTP clock information on Device A.

[DeviceA] display ptp clock

PTP profile : ITU-T G.8275.2

PTP mode : T-BC-P

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 140570-FFFE-930100

Clock type : Local

Clock domain : 44

Number of PTP ports : 1

Priority1 : 128

Priority2 : 128

Clock quality :

Class : 248

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 0 (ns)

Mean path delay : 0 (ns)

Steps removed : 0

Local clock time : Sat May 9 10:38:42 2020

Clock source info:

Clock LP Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

-------------------------------------------------------------------

Local 128 128 254 248 160 N/A N/A 65535

ToD0 128 128 32 6 32 N/A Inactive 65535

ToD1 128 128 32 6 32 N/A Inactive 65535

# Display brief PTP running information on Device A.

[DeviceA] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Master E2E Two 0 WGE1/0/1

# Display PTP clock information on Device B.

[DeviceB] display ptp clock

PTP profile : ITU-T G.8275.2

PTP mode : T-TSC-P

Slave only : No

Sync uncertain : Disabled

Clock state : Disabled

Sync uncertain : Disabled

Clock state : Disabled

Clock ID : 147405-FFFE-E30200

Clock type : Local

Clock domain : 44

Number of PTP ports : 1

Priority1 : 128

Priority2 : 255

Clock quality :

Class : 255

Accuracy : 254

Offset (log variance) : 65535

Offset from master : 50 (ns)

Mean path delay : 2169 (ns)

Steps removed : 1

Local clock time : Sat May 9 10:40:04 2020

Clock source info:

Clock LP Pri2 Accuracy Class TimeSrc Direction In-Status Offset(log variance)

-------------------------------------------------------------------

Local 128 255 254 255 160 N/A N/A 65535

ToD0 128 255 254 255 32 N/A Inactive 65535

ToD1 128 255 254 255 32 N/A Inactive 65535

# Display brief PTP running information on Device B.

[DeviceB] display ptp interface brief

State Delay mechanism Clock step Asymmetry correction Name

Slave E2E Two 0 WGE1/0/1

The output shows that Device A has been elected as the GM, and Twenty-FiveGigE1/0/1 on Device A is the master port.

13-Network Management and Monitoring Configuration Guide

Basic concepts

PTP profile

PTP domain

Clock node and PTP port (IEEE 1588 version 2, IEEE 802.1AS, SMPTE ST 2059-2, and AES67-2015)

Clock node and PTP port (ITU-T G.8275.1)

Clock nodes and PTP ports (ITU-T G.8275.2)

Technical standard

Master-member/subordinate relationship

Clock source type

Grandmaster clock

ITU-T G.8275.1

ITU-T G.8275.2

Specifying PTP for obtaining the time

Specifying a PTP profile

Restrictions and guidelines

Procedure

Restrictions and guidelines

Configuring an OC to operate only as a member clock

About this task

Restrictions and guidelines

Procedure

About this task

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

‌About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

Enabling NotSlave on a PTP port

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

Configuring PTP message transmission and receipt

Setting the interval for sending announce messages and the timeout multiplier for receiving announce messages

About this task

About this task

Procedure

Restrictions and guidelines

Procedure

About this task

About this task

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

Specifying the IPv4 UDP transport protocol for PTP messages

About this task

Restrictions and guidelines

Procedure

Configuring a source IP address for multicast PTP messages transmitted over IPv4 UDP

About this task

Restrictions and guidelines

Procedure

Configuring a destination IP address for unicast PTP messages transmitted over IPv4 UDP

About this task

Restrictions and guidelines

Prerequisites

Procedure

About this task

Restrictions and guidelines

Procedure

Setting a DSCP value for PTP messages transmitted over UDP

About this task