Contents

1 Configuring GPON multicast 1-1

1.1 GPON multicast mode overview· 1-1

1.2 Restrictions and guidelines: GPON multicast configuration· 1-2

1.3 GPON multicast tasks at a glance· 1-2

1.4 Configuring basic multicast settings· 1-2

1.5 Configuring multicast in IGMP snooping mode· 1-3

1.6 Enabling unknown multicast packet transparent transmission for UNIs· 1-4

1.7 Enabling fast-leave processing for a UNI 1-4

1.8 Configuring static multicast MAC address entries· 1-5

1.9 Display and maintenance commands for ONUs· 1-6

1.10 GPON multicast configuration examples· 1-6

1.10.1 Example: Configuring multicast in IGMP snooping mode· 1-6

 

1 Configuring GPON multicast

1.1  GPON multicast mode overview

In a GPON network, multicast applications typically enable efficient distribution of services such as IPTV. GPON multicast technology enables an OLT to send data simultaneously to a group of users subscribing to a specific service, which is more efficient than unicast. GPON unicast technology sends the same data to each ONU separately, which wastes bandwidth.

An OLT supports remotely setting the multicast mode (including IGMP snooping mode and multicast control mode) for ONUs. For more information about IGMP snooping, see IP Multicast Configuration Guide.

1. Multicast in IGMP snooping mode

In IGMP snooping mode, the OLT and ONUs mainly use IGMP report, leave, and query messages to manage dynamic multicast group membership. The OLT can implement simple user multicast access control through the multicast VLAN configuration on UNIs of ONUs.

When an ONU receives an IGMP membership report from a multicast group member, the ONU forwards the message to the OLT. When multiple members of a multicast group are attached to the ONU, the OLT will receive duplicate IGMP reports from these members. To reduce IGMP reports, enable IGMP report suppression. Within each query cycle, the ONU forwards only the first IGMP report of a multicast group to the OLT. Subsequent IGMP reports from the same multicast group are not forwarded.

2. Multicast in multicast control mode

In multicast control mode, the OLT performs the following operations:

·     The OLT maintains an access control table for user multicast services to centrally manage user multicast service access rights.

·     The OLT identifies users based on the user LLID and the VLAN tag (same as the UNI number) carried in uplink IGMP report messages. The OLT also determines whether a user has the right to access the requested multicast service and determines the related parameters.

·     The OLT uses extended multicast control OAM packets to send the ONU a user's access right to a multicast channel. This allows the ONU to forward or shut off the multicast traffic for the user. The network management system on the OLT centrally manages multicast access control. Multicast right management is governed by the OLT and executed by ONUs. The OLT also supports the cooperation between IGMP proxy and upper-layer multicast routers to dynamically request and deliver multicast traffic.

In multicast control mode, an ONU performs the following operations:

·     The ONU maintains a table for multicast address filtering and multicast forwarding. The ONU performs flow control only for the current multicast service on the ONU.

·     The ONU adds VLAN tags to untagged IGMP report and leave messages to identify users and transparently sends the messages to the OLT. The VLAN tag ID is the same as the UNI number. For example, the packets received on UNI 1 are tagged with VLAN ID 1. The ONU adds or deletes the group address filtering and multicast forwarding entries on the ONU based on the multicast control OAM packets delivered by the OLT. The multicast control OAM packets contain a series of multicast control entries. Based on the action taken on the entries, the ONU forwards or shuts off multicast traffic.

3. Comparison of the two modes

The multicast control mode provides stricter and more secure multicast flow control, and is suitable for scenarios requiring identity authentication and authorization, such as paid IPTV services. The IGMP snooping mode is a lighter multicast flow management policy that mainly relies on monitoring IGMP protocol activities, and is suitable for internal networks that do not require strict authorization.

1.2  Restrictions and guidelines: GPON multicast configuration

GPON features are supported only on the default MDC. For more information about MDCs, see Virtual Technologies Configuration Guide.

In the current software version, the OLT supports only remotely setting the multicast mode to IGMP snooping mode for ONUs.

1.3  GPON multicast tasks at a glance

To configure GPON multicast, perform the following tasks:

Configuring basic multicast settings

Configuring multicast in IGMP snooping mode

(Optional.) Enabling unknown multicast packet transparent transmission for UNIs

(Optional.) Enabling fast-leave processing for a UNI

(Optional.) Configuring static multicast MAC address entries

1.4  Configuring basic multicast settings

1. Restrictions and guidelines

For more information about IGMP-related commands, see IGMP snooping commands in IP Multicast Command Reference.

2. Procedure

Enter system view.

system-view

Enter FTTH view.

ftth

Map multicast IP addresses to a multicast VLAN.

multicast vlan-id vlan-id ip ip-address-list

By default, no multicast IP addresses are mapped to a multicast VLAN.

A multicast IP address can be mapped to only one multicast VLAN.

When receiving an IGMP report message, the OLT verifies whether the multicast IP address in the message belongs to the multicast VLAN.

¡     If the address belongs to the multicast VLAN, the OLT generates a multicast forwarding entry for the multicast VLAN.

¡     If the address does not belong to the multicast VLAN, the OLT drops the message.

Return to system view.

quit

Enable IGMP snooping globally.

igmp-snooping

By default, IGMP snooping is disabled globally.

Enable IGMP snooping in multicast VLANs.

¡     Enable IGMP snooping in multiple VLANs.

enable vlan vlan-list

¡     Execute the following commands in sequence to enable IGMP snooping in one VLAN.

quit

vlan vlan-id

igmp-snooping enable

By default, IGMP snooping is disabled in a VLAN.

Return to system view.

quit

Enter multicast VLAN view.

vlan vlan-id

Enable IGMP snooping querier.

igmp-snooping querier

By default, IGMP snooping querier is disabled.

If a network does not contain Layer 3 multicast devices, you must enable IGMP snooping querier on Layer 2 devices for them to generate and maintain multicast forwarding entries at the data link layer.

Configure the source IP address for IGMP packets.

Configure the source IP address for IGMP general queries.

igmp-snooping general-query source-ip ip-address

By default, the source IP address of IGMP general queries is the IP address of the current VLAN interface. If the current VLAN interface does not have an IP address, the source IP address is 0.0.0.0.

Configure the source IP address for IGMP group-specific queries.

igmp-snooping special-query source-ip ip-address

By default, the source IP address of IGMP group-specific queries is one of the following:

-     The source address of IGMP group-specific queries if the IGMP snooping querier of the VLAN has received IGMP general queries.

-     The IP address of the current VLAN interface if the IGMP snooping querier does not receive an IGMP general query.

-     0.0.0.0 if the IGMP snooping querier does not receive an IGMP general query and the current VLAN interface does not have an IP address.

The IGMP snooping querier might send IGMP general queries with the source IP address 0.0.0.0. The ONU PON interface that receives such queries will not be maintained as a dynamic router interface. This might prevent the associated dynamic IGMP snooping forwarding entry from being correctly created at the data link layer and eventually cause multicast traffic forwarding failures. To avoid this problem, you can configure a non-all-zero IP address as the source IP address of the IGMP queries on the IGMP snooping querier.

(Optional.) Enable dropping unknown multicast traffic.

igmp-snooping drop-unknown

1.5  Configuring multicast in IGMP snooping mode

1. Procedure

Enter system view.

system-view

Enter ONU configuration profile view.

onu config-profile profile-name

For more information about this command, see GPON Command Reference.

Assign a UNI to multicast VLANs.

uni uni-number multicast vlan vlan-id

By default, a UNI is not assigned to any multicast VLANs.

(Optional.) Configure a UNI to process downlink multicast flows. Choose one of the following options, which are mutually exclusive.

¡     Configure a UNI to remove the VLAN tags of downlink multicast flows.

uni uni-number multicast-strip-tag enable

¡     Configure a UNI to translate the VLAN IDs for downlink multicast flows.

uni uni-number multicast-translate-tag original-vlan-id to translated-vlan-id

By default, a UNI does not process VLAN tags of downlink multicast flows.

(Optional.) Configure advanced multicast parameters.

¡     Configure the number of multicast channels that users can access at the same time on a UNI.

uni uni-number multicast-group-number number

By default, the users on a UNI can access 64 multicast channels at the same time.

1.6  Enabling unknown multicast packet transparent transmission for UNIs

1. About this task

With this feature enabled, UNIs on an ONU process frames destined for the specified multicast MAC addresses as follows:

·     If the destination MAC address is 0100-ffff-ffff (referred to as global transparent transmission MAC address), the UNIs flood the multicast packets destined for the MAC addresses starting with 0x0100.

When this feature is configured, as a best practice, do not configure known multicast services.

2. Restrictions and guidelines

You can configure only global transparent transmission MAC addresses.

The global transparent transmission MAC address can be configured only by using the onu protocol transparent-multicast dest-mac mac-address command and does not support the vlan keyword.

3. Procedure

Enter system view.

system-view

Enter ONU configuration profile view.

onu config-profile profile-name

For more information about this command, see GPON Command Reference.

Enable unknown multicast packet transparent transmission for UNIs.

¡     Enable unknown multicast packet transparent transmission for all UNIs on the ONU:
onu protocol transparent-multicast dest-mac mac-address

By default, unknown multicast packet transparent transmission is disabled on UNIs. The ONU might drop unknown multicast packets.

1.7  Enabling fast-leave processing for a UNI

1. About this task

This feature immediately removes a UNI from the outgoing interface list of the forwarding table when the UNI receives an IGMP leave message for a multicast group. Then, when the ONU receives IGMP group-specific queries for that multicast group, the ONU does not forward them to that UNI.

If only one host is attached to a UNI, fast-leave processing helps improve bandwidth and resource usage. If multiple hosts in the same multicast group are attached to a UNI, when one host leaves the multicast group, the other hosts cannot receive multicast data.

Before you enable fast-leave processing, make sure the ONU is operating in IGMP snooping mode. This feature takes effect only for IGMPv2 or IGMPv3 clients.

2. Procedure

Enter system view.

system-view

Enter ONU configuration profile view.

onu config-profile profile-name

For more information about this command, see GPON Command Reference.

 (Optional.) Set the multicast mode to IGMP snooping.

multicast mode igmp-snooping

By default, the multicast mode of an ONU is IGMP snooping.

Enable fast-leave processing for UNIs.

¡     Enable fast-leave processing for all UNIs.

onu multicast fast-leave enable

¡     Enable fast-leave processing for a UNI.

uni uni-number igmp-snooping fast-leave

By default, fast-leave processing is disabled for a UNI.

You cannot use both commands.

1.8  Configuring static multicast MAC address entries

1. About this task

In Layer 2 multicast, multicast MAC address entries can be dynamically created through Layer 2 multicast protocols (such as IGMP snooping). You can also manually configure static multicast MAC address entries by binding multicast MAC addresses and ports to control the destination ports of the multicast data.

2. Restrictions and guidelines

You must specify an unused multicast MAC address when configuring a static multicast MAC address entry. A multicast MAC address is the MAC address in which the least significant bit of the most significant octet is 1.

3. Configuring static multicast MAC address entries

Enter system view.

system-view

Enter ONU subinterface view.

interface onu interface-number.subnumber

Configure a static multicast MAC address entry.

mac-address multicast mac-address vlan vlan-id

By default, no static multicast MAC address entries exist.

1.9  Display and maintenance commands for ONUs

1.10  GPON multicast configuration examples

1.10.1  Example: Configuring multicast in IGMP snooping mode

1. Network configuration

As shown in 图1-1, the ONU has been bound to ONU 1/0/1:1.

Configure multicast in IGMP snooping mode on the ONU for User 1 to access channels 225.1.2.1 through 225.1.2.255 and User 2 to access channels 225.1.3.1 through 225.1.3.255.

图1-1 Network diagram

 

2. Procedure

# Map the multicast IP addresses to multicast VLANs.

<OLT> system-view

[OLT] ftth

[OLT-ftth] multicast vlan-id 1002 ip 225.1.2.1 to 225.1.2.255

[OLT-ftth] multicast vlan-id 1003 ip 225.1.3.1 to 225.1.3.255

[OLT-ftth] quit

# Enable IGMP snooping globally.

[OLT] igmp-snooping

[OLT-igmp-snooping] quit

# Enable IGMP snooping and IGMP snooping querier and set the source IP addresses of IGMP general queries and group-specific queries to a valid IP address on the device in VLAN 1002 and VLAN 1003.

[OLT] vlan 1002

[OLT-vlan1002] igmp-snooping enable

[OLT-vlan1002] igmp-snooping querier

[OLT-vlan1002] igmp-snooping general-query source-ip 10.1.1.1

[OLT-vlan1002] igmp-snooping special-query source-ip 10.1.1.1

[OLT-vlan1002] quit

[OLT] vlan 1003

[OLT-vlan1003] igmp-snooping enable

[OLT-vlan1003] igmp-snooping querier

[OLT-vlan1003] igmp-snooping general-query source-ip 10.1.1.1

[OLT-vlan1003] igmp-snooping special-query source-ip 10.1.1.1

[OLT-vlan1003] quit

# Set the multicast mode to IGMP snooping.

[OLT] onu config-profile 1

[OLT-onu-cfgprofile-1] multicast mode igmp-snooping

# Assign UNI 1 and UNI 2 of the ONU to multicast VLANs 1002 and 1003, respectively.

[OLT-onu-cfgprofile-1] uni 1 multicast vlan 1002

[OLT-onu-cfgprofile-1] uni 2 multicast vlan 1003

# Configure UNI 1 and UNI 2 to remove the VLAN tag of downlink multicast flows.

[OLT-onu-cfgprofile-1] uni 1 multicast-strip-tag enable

[OLT-onu-cfgprofile-1] uni 2 multicast-strip-tag enable

[OLT-onu-cfgprofile-1] quit

# Configure OLT 1/0/1 as a hybrid port, and assign it to VLAN 1002 and VLAN 1003 as a tagged member.

[OLT] interface olt 1/0/1

[OLT-Olt1/0/1] port link-type hybrid

[OLT-Olt1/0/1] port hybrid vlan 1002 1003 tagged

[OLT-Olt1/0/1] quit

# Configure GigabitEthernet 1/0/1 as a trunk port that permits VLAN 1002 and VLAN 1003.

[OLT] interface gigabitethernet 1/0/1

[OLT-GigabitEthernet1/0/1] port link-type trunk

[OLT-GigabitEthernet1/0/1] port trunk permit vlan 1002 1003

[OLT-GigabitEthernet1/0/1] quit