User's Manual
FIRMWARE VERSION 1.0.7.6    HT502 USER MANUAL     Page 40 of 48  
inside dial plan feature and the Dial Plan should be: { *x+ }.  
Subscribe for MWI  Default is No. When set to “Yes” a SUBSCRIBE for Message Waiting Indication will be 
sent periodically. 
Send Anonymous 
If this parameter is set to “Yes”, the “From” header along with Privacy and P_ 
Asserted_Identity headers in outgoing INVITE message will be set to anonymous, 
blocking Caller ID. 
Anonymous Call 
Rejection 
Default is No. If set to Yes, incoming calls with anonymous Caller ID will be rejected 
with 486 Busy message. 
Special Feature  Default is Standard. Choose the selection to meet some special requirements from 
Softswitch vendors. 
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. 
Force INVITE 
Session Timer can be refreshed using INVITE method or UPDATE method. Select 
“Yes” to use INVITE method to refresh the session timer. 
Send Re-INVITE After 
Fax 
Default is No, If set to “Yes”, device will send an INVITE with audio vocoders upon 
completion of Fax to continue session in audio only. 
Enable Silence 
Detection for Fax 
Disconnect 
For fax machines that do not send a Disconnect when fax is done. This option 
Enables/Disables the detection of silence in order to know the fax has finished. The 
silence period is non-configurable and fixed to 7 seconds. 
Enable 100rel 
Enables the use of PRACK (Provisional Acknowledgment) method. 
Use First Matching  Default is No. If set to “Yes”, device will include only the first match vocoder in its 










