Grandstream Networks HT503 User Manual

 

Grandstream Networks, Inc. 

Page 28 of 38  

 

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.

The minimum session expiration (in seconds).  The default value is 90 seconds.  

If selecting “Yes” the phone will use session timer when it makes outbound calls if 
remote party supports session timer. 

If selecting “Yes” the phone will use session timer when it receives inbound calls with 
session timer request.  

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.

As a Caller, select UAC to use the phone as the refresher, or UAS to use the Callee or 
proxy server as the refresher.  

As a Callee, select UAC to use caller or proxy server as the refresher, or UAS to use 
the phone as the refresher. 

Default is No, If set to “Yes”, device will send an INVITE with audio vocoders upon 
completition of Fax to continue session in audio only. 

Default is No. If set to “Yes”, device will include only the first match vocoder in its 
200OK response, otherwise it will include all match vocoders in same order received in 
INVITE. 

Session Timer can be refreshed using INVITE method or UPDATE method. Select 
“Yes” to use INVITE method to refresh the session timer.  

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”. 

 

This defines the encoding rate for G723 vocoder. Default setting is 6.3kbps. 

This sets the iLBC size in 20ms or 30ms 

This defines payload type for iLBC. Default value is 97. The valid range is between 96 
and 127. 

Defines payload type for AAL2-G726-16.  Default value is 100.  Range is from 96 to 
127. 

Defines payload type for AAL2-G726-24.  Default value is 99.  Range is from 96 to 127. 

Defines payload type for AAL2-G726-24. Default value is 104.  Range is from 96 to 
127. 

Defines payload type for AAL2-G726-40.  Default value is 103.  Range is from 96 to 
127. 

Defines payload type for G729E.  Default value is 102.  Range is from 96 to 127 

Default is No.  VAD allows detecting the absence of audio and conserves bandwidth by 
preventing the transmission of “silent packets” over the network. 

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. 

T.38 (Auto Detect) FoIP by default, or fax Pass-Through (must use PCMU/PCMA) 

Default is Callee.  This decides whether Caller or Callee sends out the re-invite for T.38 
or Fax Pass-Through. 

Select either Fixed or Adaptive based on network conditions. 

Select Low, Medium, or High based on network conditions.