Hello , is this on asterisk ?. Please mention issue clearly .
It could be from your trunk provider end . You have 2 options
1. Ask your provider to turn off session timer request .
2. In sip.conf fiel of your asterisk try to changing session-timers configuration . Below is the extracted information from this document
you can try session-timers=refuse .
The Session-Timers can be configured on a system-wide, per-user, or per-peer basis. The peruser/per-peer settings override the global settings. The following new parameters have been added to the sip.conf file.
session-timers=["accept", "originate", "refuse"]
session-timers: The session-timers parameter defines the mode of operation of SIP session-timers feature in Asterisk. The Asterisk can be configured in one of the following three modes:
1. accept: In the “accept” mode, the Asterisk honors session-timers request made by remote end-points. A remote end-point can request Asterisk to engage session-timers by either sending it an INVITE request with Supported: timer header in it or by responding to Asterisk’s INVITE with a 200 OK that contains Session-Expires: header in it. In this mode, the Asterisk does not request session-timers from remote end-points. This is the default mode in Asterisk. 2. originate: In the “originate” mode, the Asterisk requests the remote end-points to engage session-timers in addition to honoring such requests made by the remote end-points. In order to get as much protection as possible against SIP channel leaks due to network or end-point failures, in this mode the Asterisk runs session-timers and sends periodic RE-INVITEs even if a remote end-point does not support the session-timers feature. 3. refuse: In the “refuse” mode, the Asterisk acts as if it does not support sessiontimers for inbound or outbound requests. If a remote end-point requests Asterisk to engage session-timers in a dialog (by sending Supported: timer header) then Asterisk simply ignores that request. If a remote end-point requires Asterisk to engage session-timers (by sending Require: timer header in an INVITE) then Asterisk rejects that request with a 420 Bad Extension response.