Session Timer - Yealink SIP-T4X Administration Manual

To configure session timer via web user interface:
1. Click on Account.
2. Select the desired account from the pull-down list of Account.
3. Click on Advanced.
4. Enter the desired value in the SIP Session Timer T1 (0.5~10s) field.
The default value is 0.5s.
5. Enter the desired value in the SIP Session Timer T2 (2~40s) field.
The default value is 4s.
6. Enter the desired value in the SIP Session Timer T4 (2.5~60s) field.
The default value is 5s.
7. Click Confirm to accept the change.
Session timer allows a periodic refresh of SIP sessions through a re-INVITE request, to
determine whether a SIP session is still active. Session timer is specified in RFC 4028. IP
phones support two refresher modes: UAC and UAS. The UAC mode means refreshing
the session from the client, while the UAS mode means refreshing the session from the
server. The session expiration and session refresher are negotiated via the
Session-Expires header in the INVITE message. The negotiated refresher will send a
re-INVITE request at or before the negotiated session expiration.
Procedure
Session timer can be configured using the configuration files or locally.
Configuration File <MAC>.cfg
Configuring Basic Features
Configure session timer.
For more information, refer to
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