Sip Session Timer - Yealink SIP-T54S Administrator's Manual

Select the desired value from the pull-down list of Use Outbound Proxy In Dialog.
2.
Click Confirm to accept the change.
3.

SIP Session Timer

SIP session timers T1, T2 and T4 are SIP transaction layer timers defined in
session timers are configurable on IP phones.
Timer T1
Timer T1 is an estimate of the Round Trip Time (RTT) of transactions between a SIP client and
SIP server.
Timer T2
Timer T2 represents the maximum retransmitting time of any SIP request message. The re-
transmitting and doubling of T1 will continue until the retransmitting time reaches the T2 value.
Example:
The user registers a SIP account for the IP phone and then set the value of Timer T1, Timer T2
respectively (Timer T1: 0.5, Timer T2: 4). The SIP registration request message will be re-
transmitted between the IP phone and SIP server. The re-transmitting and doubling of Timer T1
(0.5) will continue until the retransmitting time reaches the Timer T2 (4). The total registration
request retry time will be less than 64 times of T1 (64 * 0.5 = 32). The re-transmitting interval in
sequence is: 0.5s, 1s, 2s, 4s, 4s, 4s, 4s, 4s, 4s and 4s.
Timer T4
Timer T4 represents the time the network will take to clear messages between the SIP client
and server.
Configuring Basic Features
RFC 3261. These
433