After a subscriber session ends, the MSAP is removed from the system and the historical data of the subscriber is deleted. Sticky MSAP allows the MSAP to remain even when the subscriber session ends. This feature is only recommended for service providers who do not oversubscribe MSAPs in the network.
Sticky MSAP provides the following benefits.
Because the sticky MSAP is never deleted, the subscriber can start a session faster; processing time is reduced because the MSAP does not have to be recreated.
The MSAP may contain valuable historical information for the service provider. Keeping the MSAP provides a means for the service provider to look up subscriber historical data.
The MSAP is only eligible for stickiness if it was successfully created. The sticky MSAP introduces a new state: idle. An idle MSAP indicates that the subscriber on the MSAP has disconnected and the MSAP is ready for a new subscriber connection. An example is shown below:
A:BNG> # show service sap-using
===============================================================================
Service Access Points
===============================================================================
PortId SvcId Ing. Ing. Egr. Egr. Adm Opr
QoS Fltr QoS Fltr
-------------------------------------------------------------------------------
[1/1/20:1841](I) 1000 1 none 1 none Up Up
1/1/1:4000 1000 1 none 1 none Up Up
-------------------------------------------------------------------------------
Number of SAPs : 20
-------------------------------------------------------------------------------
Number of Managed SAPs : 1, indicated by [<sap-id>]
Flags : (I) = Idle MSAP
-------------------------------------------------------------------------------
===============================================================================
There are two ways to remove sticky MSAPs from the system:
Manually
The clear service id id msap command removes MSAPs. This command can remove MSAPs with active subscribers. To clear only MSAPs without any active subscriber, use the keyword idle-only.
Automatically
Sticky MSAPs can be removed with the sticky-msaps-idle-timeout command if they are idle for longer than the specified time. This can be used to keep only MSAPs that are used by regular subscribers and free the system from consuming MSAPs resources used by occasional subscribers.
The clear service id id msap command removes MSAPs.
This command can remove MSAPs with active subscribers. To clear only MSAPs without any active subscriber, use the keyword idle-only.
Persistence restoration relies on configured msap-defaults parameters under capture SAP (config>service>vpls>sap>msap-defaults)
With persistence enabled, it is generally recommended to avoid changing the default after the system has created hosts with these msap-defaults values. The hosts are not restored by the system as the msap-defaults values are no longer the same.
The Sticky MSAP feature keeps the failed MSAPs on the system and consumes system resources. These MSAPs can be cleared with the clear>service>id service-id>msap command.