Grandstream Networks HT503 user manual Vad

Session Expiration	Grandstream implemented SIP Session Timer. The session timer extension enables
	SIP sessions to be periodically “refreshed” via a SIP request (UPDATE, or re-INVITE.
	Once the session interval expires, if there is no refresh via a UPDATE or re-INVITE
	message, the session will be terminated. Session Expiration is the time (in seconds) at
	which the session is considered timed out, if no successful session refresh transaction
	occurs beforehand. The default value is 180 seconds.
Min-SE	The minimum session expiration (in seconds). The default value is 90 seconds.
Caller Request Timer	If selecting “Yes” the phone will use session timer when it makes outbound calls if
	remote party supports session timer.
Callee Request Timer	If selecting “Yes” the phone will use session timer when it receives inbound calls with
	session timer request.
Force Timer	If selecting “Yes” the phone will use session timer even if the remote party does not
	support this feature. Selecting “No” will allow the phone to enable session timer only
	when the remote party support this feature.
	To turn off Session Timer, select “No” for Caller Request Timer, Callee Request Timer,
	and Force Timer.
UAC Specify Refresher	As a Caller, select UAC to use the phone as the refresher, or UAS to use the Callee or
	proxy server as the refresher.
UAS Specify Refresher	As a Callee, select UAC to use caller or proxy server as the refresher, or UAS to use
	the phone as the refresher.
Send Re-INVITE After	Default is No, If set to “Yes”, device will send an INVITE with audio vocoders upon
Fax	completition of Fax to continue session in audio only.
Use First Matching	Default is No. If set to “Yes”, device will include only the first match vocoder in its
Vocoder in 200OK SDP	200OK response, otherwise it will include all match vocoders in same order received in
	INVITE.
Force INVITE	Session Timer can be refreshed using INVITE method or UPDATE method. Select
	“Yes” to use INVITE method to refresh the session timer.
Preferred Vocoder	The HT503 supports up to 5 different Vocoder types including G.711 A-/U-law, G.726
	(Supports bit rates 16, 24, 32 and 40), G.723.1, G.729A/B/E and iLBC. The user can
	configure Vocoders in a preference list that will be included with the same preference
	order in SDP message. The first Vocoder is entered by choosing the appropriate
	option in “Choice 1”. The last Vocoder is entered by choosing the appropriate option in
	“Choice 8”.
G723 Rate:	This defines the encoding rate for G723 vocoder. Default setting is 6.3kbps.
iLBC Frame Size:	This sets the iLBC size in 20ms or 30ms
iLBC Payload Type:	This defines payload type for iLBC. Default value is 97. The valid range is between 96
	and 127.
AAL2-G726-16 Payload	Defines payload type for AAL2-G726-16.	Default value is 100.	Range is from 96 to
Type	127.
AAL2-G726-24 Payload	Defines payload type for AAL2-G726-24.	Default value is 99.	Range is from 96 to 127.
Type
AAL2-G726-32 Payload	Defines payload type for AAL2-G726-24. Default value is 104.		Range is from 96 to
Type	127.
AAL2-G726-40 Payload	Defines payload type for AAL2-G726-40.	Default value is 103.	Range is from 96 to
Type	127.
G729E Payload Type	Defines payload type for G729E. Default value is 102. Range is from 96 to 127
VAD	Default is No. VAD allows detecting the absence of audio and conserves bandwidth by
	preventing the transmission of “silent packets” over the network.
Symmetric RTP	Default is No. When set to “Yes” the device will change the destination to send RTP
	packets to the source IP address and port of the inbound RTP packet last received by
	the device.
Fax Mode	T.38 (Auto Detect) FoIP by default, or fax Pass-Through (must use PCMU/PCMA)
Fax Tone Detection	Default is Callee. This decides whether Caller or Callee sends out the re-invite for T.38
Mode	or Fax Pass-Through.
Jitter Buffer Type	Select either Fixed or Adaptive based on network conditions.
Jitter Buffer Length	Select Low, Medium, or High based on network conditions.
Grandstream Networks, Inc.	HT503 User Manual		Page 28 of 38
	Firmware 1.0.4.2		Last Updated: 06/2011