I am fairly new to Kamailio and had a question regarding how to use Kamailio to enable Session refresh functionality when Kamailio is acting as Sip Stateful Proxy. 

Kamailio Version used: 5.3.2 with Call Load based routing using the dispatcher module.

* From what i understand from the documentation, Kamailio will probably not be acting as a session refresher, but Kamailio can tear down the call in case session refresh is negotiated, between the caller and the callee(via Kamailio Sip Proxy), and no message exchange happens in the duration set in Session-Expires header. Is my understanding correct?

* I believe the above functionality is possible by using the sst and dialog module. I have set the same according to the documentation but I keep getting the following error:

"dialog [dlg_handlers.c:681]: get_dlg_timeout(): invalid AVP value, using default timeout"

Can someone share a working example?

* When i tried hardcoding the timeout value by setting the timeout_avp to a specific value, Kamailio did sense a timeout and hence sent a BYE towards the caller and the Callee side both(which is what the requirement is), however, i do see the dialog is still not cleared in the "kamcmd dispatcher.list". Output excerpt below for reference:

[root@CPaaSVM ~]# kamcmd dispatcher.list
{
        NRSETS: 1
        RECORDS: {
                SET: {
                        ID: 1
                        TARGETS: {
                                DEST: {
                                        URI: sip:172.27.44.121:5080;transport=tcp
                                        FLAGS: AP
                                        PRIORITY: 0
                                        ATTRS: {
                                                BODY: duid=sample-cas;maxload=1000
                                                DUID: sample-cas
                                                MAXLOAD: 1000
                                                WEIGHT: 0
                                                RWEIGHT: 0
                                                SOCKET:
                                        }
                                        LATENCY: {
                                                AVG: 111.304000
                                                STD: 1042.193000
                                                EST: 2.385000
                                                MAX: 9999
                                                TIMEOUT: 1
                                        }
                                        RUNTIME: {
                                                DLGLOAD: 1
                                        }
                                }
                        }
                }
        }
}

It is noteworthy that in case the BYE is initiated by either the caller or the callee, the dialog is cleared properly and the DLGLOAD is set to 0 on call termination. 

Any pointers for the above questions would be highly appreciated. 

Regards,

Harneet

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