Contents

Configuring WLAN ISSU·· 1

About WLAN ISSU· 1

Background· 1

Technical advantages· 1

Application scenarios· 1

Restrictions: Hardware compatibility with WLAN ISSU· 1

Restrictions and guidelines: WLAN ISSU configuration· 2

WLAN ISSU tasks at a glance· 2

Configuring WLAN ISSU· 2

Configuring WLAN ISSU maintenance· 5

Triggering ISSU rollback for APs· 5

Triggering ISSU migration for APs· 6

Terminating the ISSU process for APs· 7

Stopping the WLANISSU process· 7

Verifying and maintaining WLAN ISSU· 7

 

Configuring WLAN ISSU

About WLAN ISSU

WLAN In-Service Software Upgrade (ISSU) is a highly reliable method to upgrade the device startup software without disrupting services. Use WLAN ISSU to upgrade the system with minimal or no service disruption.

Background

With the widespread adoption of wireless network technologies, people rely significantly more on wireless networks. Wireless networks have become essential in daily life and work, covering personal devices, business applications, and industrial systems. However, administrators must upgrade the device software to fix bugs or add new features. This causes prolonged wireless network disruptions, which users increasingly find unacceptable.

To address this issue, the WLAN ISSU upgrade solution emerged. This solution minimizes or eliminates wireless service disruptions during device software version upgrades. It maximizes the continuity and stability of wireless networks, ensuring users enjoy a consistent and high-quality experience.

Technical advantages

WLAN ISSU offers the following technical advantages:

·     Uninterrupted or minimally disrupted wireless services: Upgrade APs in batches to maintain wireless operations during the process. It can minimize the downtime and maximize user experience with continuous network access.

·     Seamless switchover: Use multiple steering operations to enable wireless clients to switch between APs smoothly. Users will hardly notice the switchover process.

Application scenarios

During device operation, the current software may fail to meet network or user service requirements. Traditional software upgrades require a device reboot, which disrupts user services and degrades the experience. In this case, you can use WLAN ISSU to upgrade the software, ensuring minimal or no service disruption during the process.

Restrictions: Hardware compatibility with WLAN ISSU

Hardware series	Model	Product code	Feature compatibility
WX3500X series	·     WX3510X ·     WX3520X ·     WX3540X	·     EWP-WX3510X ·     EWP-WX3520X ·     EWP-WX3540X	Yes
WX3500X-E series	WX3508X-E	EWP-WX3508X-E	Yes
Access controller modules	LSEM1WBC120G0	LSEM1WBC120G0	No

 

Hardware series	Model	Product code	Feature compatibility
WX3500X-G series	WX3520X-G	EWP-WX3520X-G	Yes

 

Hardware series	Model	Product code	Feature compatibility
WX3800X series	·     WX3820X ·     WX3840X	·     EWP-WX3820X ·     EWP-WX3840X	Yes

 

Restrictions and guidelines: WLAN ISSU configuration

The master AC in this document refers to the AC with the higher AP connection priority in dual-link backup, and the backup AC refers to the one with the lower AP connection priority.

WLAN ISSU tasks at a glance

To configure WLAN ISSU, perform the following tasks:

1.     Configuring WLAN ISSU

2.     (Optional.) Configuring WLAN ISSU maintenance

¡     Triggering ISSU rollback for APs

¡     Triggering ISSU migration for APs

¡     Terminating the ISSU process for APs

¡     Stopping the WLANISSU process

Configuring WLAN ISSU

About this task

Application scenarios

Perform this task to upgrade device versions in a dual-link backup network.

Operating mechanism

The complete WLAN ISSU process is as follows:

1.     Use the boot-loader file command to preload the target image files for the master and backup ACs. Restart the backup AC to perform version upgrade and use the wlan ap-image-deploy command to deploy the files to the master AC and online APs.

2.     On the master AC, run the wlan system internal ap access-forbidden enable command to forbid AP access. This ensures APs automatically associate with the backup AC after rebooting and upgrading.

3.     Use the wlan issu ap-upgrade or wlan issu ap-upgrade apply-compute-result command to trigger the WLAN ISSU process.

 

NOTE: The wlan issu ap-upgrade apply-compute-result command can reference an existing ISSU calculation result and trigger AP ISSU. Recalculation of ISSU is not required.

 

4.     The system calculates the upgrade batches and the list of APs to upgrade per batch based on the specified upgrade range, upgrade percentage, or maximum number of APs to upgrade per batch.

5.     The upgrade process for each batch is as follows:

a.     The master AC issues a command to the upgrade APs to block new client access.

b.     Based on the configured power increase and decrease values, the master AC increases the transmit power of non-upgrade neighbor APs and decreases the transmit power of upgrade APs. This encourages clients to roam to non-upgrade neighbor APs.

c.     The system waits for the duration configured by the wlan issu power-adjust roam-wait-time command.

d.     The system sends 802.11v BTM Request packets based on the configured quantity and interval to guide 802.11v clients to roam from the upgrade APs to non-upgrade neighbor APs.

e.     After setting the transmit power of upgrade APs to 1 dBm, the system waits a period of time set by the wlan issu power-adjust min-power roam-wait-time command. This allows both 802.11v-capable and 802.11v-incapable clients to detect weak signals and proactively roam to non-upgrade neighbor APs.

f.     After wlan issu stop-beacon enable is configured, the upgrade APs stop sending Beacon frames and wait for the duration configured by the wlan issu stop-beacon roam-wait-time command. This allows clients to proactively roam to non-upgrade neighbor APs.

g.     After wlan issu kick-client enable is configured, the system logs off any remaining clients on the upgrade APs.

h.     The system restarts and upgrades the upgrade APs and make the APs come online from the backup AC.

i.     After the waiting time set by the wlan issu reboot-result-check time command expires, the system checks whether all APs in the current batch have successfully connected to the backup AC.

-     If all APs are online, the system restores the power of these APs and their non-upgrade neighbors to the original values, and then proceed to upgrade the next batch of APs.

-     If not all APs are online, the system keeps waiting. It retries up to 3 times. If some APs still fail to come online, the system proceeds to upgrade the next batch of APs.

j.     The system upgrades all batches of APs and brings them online on the backup AC.

6.     Then, the system restarts the master AC to complete the version upgrade.

7.     Make sure master CAPWAP tunnel preemption is enabled on the master AC, so that all APs on the backup AC can reconnect to the master AC.

 

NOTE: The process for all APs to switch back from the backup AC to the master AC is similar to the one described above. It follows the upgrade batches and the AP list per batch.

 

The optimized upgrade process ensures batch upgrades for APs. At the same time, the system adjusts the transmit power and sends 802.11v BTM Request packets to guide clients to roam to non-upgrade neighbor APs. This significantly reduces the impact of device upgrades on user experience.

Restrictions and guidelines

·     To use WLAN ISSU, you must enable SmartMC, specify the master AC as the TM, and the backup AC as the TC. Before enabling SmartMC, make sure the WLANISSU process is running.

·     WTs and WTUs do not support WLAN ISSU.

Prerequisites

Before configuring WLAN ISSU, complete the following tasks first:

1.     Preload the image files on the master and backup ACs. Restart the backup AC for version upgrade. Then, distribute the image files from the master AC to online APs.

2.     On the master AC, run the wlan system internal ap access-forbidden enable command to forbid AP access. This ensures APs automatically associate with the backup AC after rebooting and upgrading.

Procedure

1.     Enter system view.

system-view

2.     Trigger an AP ISSU. Choose the options to configure as needed:

¡     Trigger an AP ISSU.

wlan issu ap-upgrade { all | ap-group group-name } [ compute-only ]

¡     Reference an existing ISSU calculation result and trigger an AP ISSU.

wlan issu ap-upgrade apply-compute-result result-id

3.     (Optional.) Configure the upgrade batches and the list of the APs to upgrade in each batch. Choose the options to configure as needed:

¡     Specify the percentage of APs for each batch.

wlan issu ap-upgrade percent percent

By default, the system upgrades 15% APs per batch.

¡     Set the maximum number of APs to upgrade per batch.

wlan issu ap-upgrade per-batch-max max-number

By default, the system upgrades up to 1000 APs per batch.

4.     (Optional.) Configure the power adjustment values for upgrade APs and non-upgrade neighbor APs.

wlan issu power-adjust { down | up } value

By default, the system increases the power of non-upgrade neighbor APs by 3 dBm and decreases the power of upgrade APs by 3 dBm.

5.     (Optional.) Specify the waiting time for clients to roam to non-upgrade neighbor APs after the power adjustment.

wlan issu power-adjust roam-wait-time value

By default, the system waits 60 seconds for clients to roam to non-upgrade neighbor APs after the power adjustment.

6.     (Optional.) Set the interval for upgrade APs to send BTM Request packets.

wlan issu btm-request-interval interval

By default, an upgrade AP sends a BTM Request packet every 3 seconds.

7.     (Optional.) Specify the number of BTM Request packets sent by an upgrade AP.

wlan issu btm-request-count count

By default, an upgrade AP sends 10 BTM Request packets.

8.     (Optional.) Set the waiting time for clients to roam proactively after the transmit power of upgrade APs is reduced to 1 dBm.

wlan issu power-adjust min-power roam-wait-time value

By default, the system waits 5 seconds for clients to roam proactively after reducing the transmit power of upgrade APs to 1 dBm.

9.     (Optional.) Enable upgrade APs to stop sending Beacon frames.

wlan issu stop-beacon enable

By default, upgrade APs do not stop sending Beacon frames.

10.     (Optional.) Set the waiting time after upgrade APs stop sending Beacon frames.

wlan issu stop-beacon roam-wait-time value

By default, the system waits 5 seconds after upgrade APs stop sending Beacon frames.

11.     (Optional.) Enable forced logoff of clients.

wlan issu kick-client enable

By default, forced logoff of clients is enabled.

12.     (Optional.) Set the waiting time before the system checks the association status of upgrade APs on the backup AC.

wlan issu reboot-result-check time value

By default, the system waits 180 seconds and then checks the association status of upgrade APs after the APs restart.

Configuring WLAN ISSU maintenance

Triggering ISSU rollback for APs

About this task

Application scenarios

Use this function when a dual-link backup network experiences disruption during an ISSU. Perform this task to perform a rollback on the APs that have completed the upgrade and are online on the backup AC, and then switch them back to the master AC through ISSU. This restores the device environment to its initial pre-upgrade state.

Operating mechanism

1.     First, the system performs ISSU calculation on the backup AC for the APs that need rollback to obtain the AP rollback list. If the AP upgrade list on the backup AC remains uncleared when the ISSU process is interrupted, the backup AC uses the upgrade list as the rollback list.

2.     Then, the system rolls back the APs in batches, and finally switches them over to the master AC for reconnection.

The AP rollback and switchover process is similar to the batch upgrade process triggered by wlan issu ap-upgrade.

Restrictions and guidelines

·     Use this function only to roll back partial ISSU processes on the backup AC after an ISSU is interrupted. Do not perform this task on the master AC.

·     To perform this task, follow these restrictions and guidelines:

¡     If the master AC has completed the upgrade and reboot process when the ISSU is interrupted, first roll back the version on the master AC.

¡     On the backup AC, deploy the rollback version to online APs.

¡     Enable SmartMC. Specify the backup AC as the TM and the master AC as the TC. Before enabling SmartMC, make sure the WLANISSU process is running.

¡     Make sure you have executed the undo wlan system internal ap access-forbidden enable command on the master AC to remove the AP access limit. This ensures APs can automatically reconnect to the master AC after the rollback and reboot.

·     WTs and WTUs do not support WLAN ISSU.

Procedure

1.     Enter system view.

system-view

2.     Trigger ISSU rollback for APs.

wlan issu ap-rollback { all | ap-group group-name }

Triggering ISSU migration for APs

About this task

Application scenarios

Use this function when a dual-link backup network experiences disruption during an ISSU. Perform this task to trigger ISSU migration for APs that have completed the upgrade and are online on the backup AC but have not finished the batch switchback process. This completes all steps of ISSU interruption.

Operating mechanism

1.     First, the system performs ISSU calculation on the backup AC for the APs that need switchback to obtain the AP migration list. If the AP upgrade list on the backup AC remains uncleared when the ISSU process is interrupted, the backup AC uses the upgrade list as the migration list.

2.     Then, the system migrates the APs in batches, and finally switches them over to the master AC for reconnection.

The AP migration and switchover process is similar to the batch upgrade process triggered by wlan issu ap-upgrade.

Restrictions and guidelines

·     Use this function only to trigger ISSU migration for APs with incomplete batch rollback processes on the backup AC after an ISSU is interrupted. Do not perform this task on the master AC.

·     To trigger ISSU migration for an aborted ISSU process using this function, make sure the master AC has completed the upgrade and reboot process.

·     Enable SmartMC. Specify the backup AC as the TM and the master AC as the TC. Before enabling SmartMC, make sure the WLANISSU process is running.

·     WTs and WTUs do not support WLAN ISSU.

Procedure

1.     Enter system view.

system-view

2.     Trigger ISSU migration for APs.

wlan issu ap-move { all | ap-group group-name }

Terminating the ISSU process for APs

Restrictions and guidelines

You cannot perform this task at the scanning, calculation, waiting for switchback, or switchback stages. This task is available only at the AP upgrade phase. This task cannot stop the ongoing upgrade. It can only stop the upgrade of subsequent batches.

As a best practice, do not terminate an ISSU process. Before performing this task, make sure you understand the impact.

Procedure

1.     Enter system view.

system-view

2.     Terminate the AP ISSU process.

wlan issu ap-upgrade abort

Stopping the WLANISSU process

Restrictions and guidelines

If the WLANISSU upgrade process encounters an exception, you can use this function to terminate the process. Make sure this feature is used only for the maintenance personnel to locate issues.

Procedure

1.     Enter system view.

system-view

2.     Stop the WLANISSU process.

undo wlan issu enable

By default, the WLANISSU process is not started.

Verifying and maintaining WLAN ISSU

Perform display tasks in any view.

·     Display the calculation results for AP batch upgrades.

display wlan issu ap-upgrade compute-result { all | result-id result-id }

·     Display the history of the most recent AP ISSU operations.

display wlan issu ap-upgrade history { all | record-id record-id }

·     Display real-time statistics for the ongoing AP ISSU operation.

display wlan issu ap-upgrade in-process statistics