AudioCodes 445HD - Configuring SIP Timers; Table 5-8: SIP Timers Parameters

Administrator's Manual 5. Configuring VoIP Settings
Version 3.4.3 71 400HD Series IP Phones
5.1.5 Configuring SIP Timers
SIP Timers can be configured.
 To configure SIP timer settings:
• Use the table as reference.
Table 5-8: SIP Timers Parameters
Parameter Description
voip/signalling/sip/sip_t1
The time interval (in msec) between the first
transmission of a SIP message and the first
retransmission of the same message (according to
RFC 3261).
The valid range is 100 to 60000. The default value is
500.
Note: The time interval between subsequent
retransmissions of the same SIP message starts with
SipT1Rtx and is multiplied by two until SipT2Rtx. For
example (assuming that SipT1Rtx = 500 and SipT2Rtx
= 4000):
 The first retransmission is sent after 500 msec.
 The second retransmission is sent after 1000
(2*500) msec.
 The third retransmission is sent after 2000 (2*1000)
msec.
 The fourth retransmission and subsequent
retransmissions until SIPMaxRtx are sent after 4000
(2*2000) msec.
Note also:
If dual registration / redundant Genesys server is
configured and the configuration file parameter
'voip/signalling/sip/redundant_proxy/dual_reg/t1' is then
configured, its value will override 'Retransmission Timer
T1'. See also Section A.3.12 and Section A.3.12.1.
voip/signalling/sip/redundant_proxy/dual
_reg/t1
Only relevant if dual registration / redundancy server is
configured. Allows quicker retransmission of SIP
messages. Default: 20 milliseconds. Range: 20-200.
voip/signalling/sip/sip_t2
The maximum interval (in msec) between
retransmissions of SIP messages (according to RFC
3261).
 The valid range is 4000 to 60000.
 The default value is 4000.
Note: The time interval between subsequent
retransmissions of the same SIP message starts with
SipT1Rtx and is multiplied by two until SipT2Rtx.
voip/signalling/sip/sip_t4
The SIP T4 retransmission timer according to RFC
3261.
 The valid range is 5000 to 60000.
 The default value is 5000.