Cisco Systems SPA9000 manual SIP Timer Values sec section, SIP T2

SPA9000 Field Reference

Voice tab

B

RFC 2543 Call Hold	If set to yes, unit will include c=0.0.0.0 syntax in SDP when
	sending a SIP re-INVITE to the peer to hold the call. If set to
	no, unit will not include the c=0.0.0.0 syntax in the SDP. The
	unit will always include a=sendonly syntax in the SDP in
	either case.
	Default: yes
Mark All AVT Packets	If set to yes, all AVT tone packets (encoded for redundancy)
	have the marker bit set. If set to no, only the first packet has
	the marker bit set for each DTMF event.
	Default: yes
SIP TCP Port Min	The lowest TCP port number that can be used for SIP
	sessions.
	Default: 5060
SIP TCP Port Max	The highest TCP port number that can be used for SIP
	sessions.
	Default: 5080

Voice tab > SIP page

SIP Timer Values (sec) section

SIP T1	RFC 3261 T1 value (RTT estimate), which can range from 0 to
	64 seconds.
	Default: .5
SIP T2	RFC 3261 T2 value (maximum retransmit interval for non-
	INVITE requests and INVITE responses), which can range
	from 0 to 64 seconds.
	Default: 4
SIP T4	RFC 3261 T4 value (maximum duration a message remains in
	the network), which can range from 0 to 64 seconds.
	Default: 5
SIP Timer B	RFC 3261 INVITE transaction time-out value, which can range
	from 0 to 64 seconds.
	Default: 32
SIP Timer F	RFC 3261 Non-INVITE transaction time-out value, which can
	range from 0 to 64 seconds.
	Default: 32

SPA9000 Voice System Administration Guide 204