Hello,

the CANCEL is an own transaction, so you can not access AVPs from the INVITE transaction. Refer e.g., to RFC 3261, section 9.1.

Cheers,

Henning

From: Scherney Theodor <Theodor.Scherney@kontron.com>
Sent: Donnerstag, 23. März 2023 09:37
To: Kamailio (SER) - Development Mailing List <sr-dev@lists.kamailio.org>
Subject: [sr-dev] $avp(id) - AVPs - Problem

Hello,

http://www.kamailio.org/wiki/cookbooks/5.5.x/pseudovariables#avp_id_-_avps

AVPs are special variables that are attached to SIP transactions.

It is R/W variable (you can assign values to it directly in configuration file).

Call scenario:

Alice calls Bob.

Here I set the AVP:

route[REQINIT] {

if (is_method("INVITE")){

    $avp(ICID_AVP) = $hdr(P-Charging-Vector);

}

Receiving 200 Ok at onreply_route[term_reply] { } I can access the AVP.

Other scenario:

Alice calls Bob. Alice cancels the call. In this case I can’t access the AVP.

route[term_subsequent] {

   if (is_method("CANCEL")){

         if (t_lookup_cancel()) {

                xlog("L_INFO", "INVITE transaction exists");

                  xlog("L_INFO", "ICID_AVP [$avp(ICID_AVP)]\n");

        }                                     }

}

2023-03-23T09:11:56.332778+01:00 172.29.21.53 vict2-scscf[44536] - [logSDID@20306 resource="xlog"] INFO: <script>: INVITE transaction exists

2023-03-23T09:11:56.333292+01:00 172.29.21.53 vict2-scscf[44536] - [logSDID@20306 resource="xlog"] INFO: <script>: ICID_AVP [<null>]

What could be the problem?

Thanks!

BR

Theo