Administrator’s Guide for SIP-T5 Series Smart Media Phones334Parameters Permitted Values Default60Description:Configures the SIP session timer of T4 (in seconds).T4 represents the maximum duration a message will remain in the network.Web User Interface:Settings->SIP->SIP Session Timer T4 (2.5~60s)Phone User Interface:NoneTo configure session timer via web user interface:1. Click on Settings->SIP.2. Enter the desired value in the SIP Session Timer T1 (0.5~10s) field.3. Enter the desired value in the SIP Session Timer T2 (2~40s) field.4. Enter the desired value in the SIP Session Timer T4 (2.5~60s) field.5. Click Confirm to accept the change.Session TimerSession timer allows a periodic refresh of SIP sessions through an UPDATE request, to determinewhether a SIP session is still active. Session timer is specified in RFC 4028. IP phones support tworefresher modes: UAC and UAS. Whether the endpoint functions as a UAC or a UAS depends onthe UA that initiates the SIP request. If the initiator is configured as UAC, the other client or theSIP server will function as a UAS. If the initiator is configured as UAS, the other client or the SIP
