Linksys SPA942 Sticky, If this feature is enabled, the IP telephony ignores further, select no

Customizing SPA9x2 Extensions

Network Settings and SIP Settings

Parameter	Description
SIP Transport	Select from UDP, TCP, or TLS.
	Defaults to UDP.
SIP Port	Port number of the SIP message listening and transmission port.
	Defaults to 5060.
SIP 100REL Enable	To enable the support of 100REL SIP extension for reliable
	transmission of provisional responses (18x) and use of PRACK
	requests, select yes. Otherwise, select no.
	Defaults to no.
EXT SIP Port	The external SIP port number.
Auth Resync-Reboot	If this feature is enabled, the SPA9x2 authenticates the sender when it
	receives the NOTIFY resync reboot (RFC 2617) message. To use this
	feature, select yes. Otherwise, select no.
	Defaults to yes.
SIP Proxy-Require	The SIP proxy can support a specific extension or behavior when it
	sees this header from the user agent. If this field is configured and the
	proxy does not support it, it responds with the message,
	unsupported. Enter the appropriate header in the field provided.
SIP Remote-Party-ID	To use the Remote-Party-ID header instead of the From header, select
	yes. Otherwise, select no.
	Defaults to yes.
Referor Bye Delay	Controls when the SPA9x2 sends BYE to terminate stale call legs upon
	completion of call transfers. Multiple delay settings (Referor, Refer
	Target, Referee, and Refer-To Target) are configured on this screen. For
	the Referor Bye Delay, enter the appropriate period of time in
	seconds.
	Defaults to 4.
Refer Target Bye Delay	For the Refer Target Bye Delay, enter the appropriate period of time in
	seconds.
	Defaults to 0.
Sticky 183	If this feature is enabled, the IP telephony ignores further 180
	SIP responses after receiving the first 183 SIP response for an
	outbound INVITE. To enable this feature, select yes. Otherwise,
	select no.
	Defaults to no.
Auth INVITE	When enabled, authorization is required for initial incoming
	INVITE requests from the SIP proxy.
Referee Bye Delay	For the Referee Bye Delay, enter the appropriate period of time in
	seconds.
	Defaults to 0.

Linksys SPA9x2 Phone Administration Guide 98