CUCM How to modify Session-Expires

[gozzita]

Hello, team!

I am attempting to modify or remove the Session-Expires field from an Invite message. I also wish to adjust the re-Invite timer across CUCM, CMS, and MRA Jabber.

To achieve this, I have developed several Lua scripts which successfully modify the Session-Expires timer for outbound Invites. However, I have encountered an issue where CUCM continues to send re-Invite messages every 15 minutes, regardless of the SE timer setting. Even if I have set to 3600.

Is there a way to adjust the re-Invite timer for CUCM?

[b.winter]

About the LUA script: You are just removing something from the message, that CUCM has already sent out. But the "mechnism" of the session refresh is still ongoing. So you effort is worth nothing.

Check the service parameter for the Callmanager service to change the value of "SIP Session Expires Timer", it's default 1800s (15min).

[gozzita]

I tried changing the "SIP Session Expires Timer" setting. If set it to 900, then we get every 450 re-invites for MRA Jabber. But every 900 CUCM sends re-invite to CMS.

[b.winter]

And where is the problem now? Sounds as "works as designed" to me.
Completely normal to send the Re-Invite after 450s, if you set the timer to 900s. --> Always half of the time in the Session Expires header. Check the RFC for it.

About CMS: Have you reset the SIP-Trunk? It cannot be, that CUCM uses 2 different timers.

[M02@rt37]

Hello @gozzita,

In CUCM, the re-INVITE timer behavior is controlled by the Session Timer setting in the SIP profile associated with the specific SIP trunk or device. This setting determines the frequency at which CUCM sends re-INVITE messages for session refresh.

The re-INVITE timer behavior might also be influenced by other devices in the call flow, such as CMS and MRA Jabber. Make sure to review and adjust the session timer settings on these devices as well, if necessary, to ensure consistent behavior across the entire call path.

[b.winter]

About which value in the SIP profile are you talking? AFAIK, there is no parameter for that in the SIP-profile.

[M02@rt37]

@b.winter 

Then, I will double check.

Thanks 

[M02@rt37]

@gozzita 

Here:

https://community.cisco.com/t5/ip-telephony-and-phones/cucm-sip-trunk-disabling-sip-session-timer/td-p/3702991

[gozzita]

I tried this way. Same thing. CUCM send re-invite at 900 seconds.

[Ibrahim AlQumairi]

You can increase the re-invite from cucm service parameters > cisco callmanager service >  SIP Expires Timer which will take effect globally. The default value is 180000 msec 

otherwise, if you want to remove the session expiration value from the sip invite message use  SIP Normalization Script and assign it to point sip-trunk, but in this way, I think that the CUCM will still expire the sip session within 180000 msec.

[b.winter]

Hi, this was already written in my answer down below. Why do you answer with the same information again? And no, "SIP Expires Timer" is something different.