Peer Optimization

Upon getting a CSR/MBR/Echo Request from a peer over S8 interface, the SMF marks the peer as Roaming SGW and uses the path management-related configuration done for the S8 interface.

There is no difference in path failure detection logic for partner SGWs. Upon detecting the session as roaming session via the S5 interface, SMF marks the peer as Roaming SGW and updates the path management-related configuration done for the S8 interface.

SMF provides an option to disable the path management by disabling the Echo for S8 interface. Disabling Echo can be done by configuring the Echo Interval as 0. In this case, no Echo would be initiated from the SMF for the roaming SGWs.

SMF, by default, adds a route for roaming SGW, if there is no VRF association at the VIP interface. If the VRF association exists, then SMF will not install the routes.

Note

A smaller cp-idle/up-idle timeout for roamer sessions is recommended so that peer restart impact can be minimized. It can minimize the (stale session) non-detection of peer path failure or peer restart.