Sip Session Timer; Sip Session Timer Configuration - Yealink SIP-T3 Administrator's Manual

SIP Session Timer

SIP session timers T1, T2 and T4 are SIP transaction layer timers defined in
configurable on the 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 doub-
ling 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-trans-
mitting interval in sequence is 0.5s, 1s, 2s, 4s, 4s, 4s, 4s, 4s, 4s and 4s.
Timer T4
Timer T4 represents that the network will take to clear messages between the SIP client and server.
Topic

SIP Session Timer Configuration

SIP Session Timer Configuration
The following table lists the parameters you can use to configure the SIP session timer.
Parameter sip.timer_t1
Description It configures the SIP session timer T1 (in seconds).
Permitted
Float from 0.5 to 10
Values
Default 0.5
Web UI Settings > SIP > SIP Session Timer T1 (0.5~10s)
Parameter sip.timer_t2
Description It configures the SIP session timer T2 (in seconds).
Permitted
Float from 2 to 40
Values
Default
4
Web UI
Settings > SIP > SIP Session Timer T2 (2~40s)
Parameter sip.timer_t4
Description It configures the SIP session timer T4 (in seconds).
Permitted
Float from 2.5 to 60
Values
Default
5
RFC 3261. These session timers are
<y0000000000xx>.cfg
<y0000000000xx>.cfg
<y0000000000xx>.cfg
General Features
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