EP-44SIP(H) WEBSERVER
3.3.1.3. SIP Timers
The SIP timer service allows SIP applications to schedule and manage timers and receive
notifications when timers expire. Timers are events that can be scheduled to run once at a specific
time, or to repeat at configurable intervals. Normally these parameters are not modified.
Retransmission Timer T1: The valid numeric range is 100 to 60000 and the default value is 500. T1
is the time interval (in ms) between the first transmission of a SIP message and the answer of the
same message (RTT round‐trip time established in RFC 3261).
Retransmission Timer T2: The valid numeric range is 4000 to 60000 and the default value is 4000.
T2 is the maximum interval (in ms) between SIP message retransmissions (according to RFC 3261).
Retransmission Timer T4: The valid range is 5000 o 60000 and the default value is 5000. T4 is the
maximum time that a message could stay in network (TTL) according to RFC 3261.
INVITE Timer: The SIP INVITE timer according to RFC 3261 and the valid numeric range is 0 to
65535. The default number is 32000.
Session‐Expires: Establish the time (in seconds) in which the call will be timed out if a successful
INVITE transaction does not occur. The valid numeric range is 0 to 65535. The typical value is 1800.
Min‐SE: The minimum value for the session interval. The valid numeric range is 0 to 65535.
Normally it is set to 90.
Configure the SIP timer parameters and then click Submit, but normally these parameters are left
unchanged.
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