GTP-U - How the restarts in GTP-U entity are detected if no break in receiving Echo Rsp from peer GTP-U entity?

Question

This is regarding the scenario where GTP-U peer got restarted and again came to service. However,the other GTP-U entity could not detect the restart of peer GTP-U entiity as it keep receving Echo Response. I had read the Restart Counter/(Recovery IE), is used to detect such restarts. But, as per spec 29.281, Restart counter is no longer use and ignored. In such case how such quick GTP-U restarts are detected by peer GTP-U? Is it so that in this case no recovery action needed for User Plane ?

I do see that we have Private Extension IE but again that is vendor specific so that can not be used for interconnection with devices with other Vendors.

Comments

Let me read I was in the impression that restart counter is used for such purpose.

Answer 1

Yes you are right it is very clearly saying -

"The Restart Counter value in the Recovery information element shall not be used, i.e. it shall be set to zero by the sender and shall be ignored by the receiver. The Recovery information element is mandatory due to backwards compatibility reasons."

So if we read the last sentence we can deduce that recovery is not needed. Now I assume this as that peer is restarted the local will either detect the peer failure by the way of path management or if it comes up well within the time local will not require any action.

Comments are welcome.