Yealink SIP-T27P [291/841] Procedure

Configuring Basic Features

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The default value is 4.

4. Enter the desired value in the SIP Session Timer T4 (2.5~60s) field.

The default value is 5.

5. 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/UPDATE request at or before the negotiated session expiration.

Procedure

Session timer can be configured using the configuration files or locally.

Configuration File

<MAC>.cfg

Configure session timer.

Parameters:

account.X.session_timer.enable

account.X.session_timer.expires

account.X.session_timer.refresher

Local

Web User Interface

Configure session timer.

Navigate to:

http://<phoneIPAddress>/servlet