Grandstream Networks HT502 - Manual (Page 26)

Grandstream Networks, Inc. HT-502 User Manual Page 26 of 31
Firmware Version 1.0.1.21 Last Updated: 12/2008
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.
Preferred Vocoder The HT502 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, iLBC and AAL2. 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 Default is 6.3kbps. Defines the encoding rate for G.723 vocoder.
iLBC Frame Size Sets the iLBC frame size in 20ms or 30ms
iLBC Payload type Defines payload type for iLBC. Default value is 97. The valid range is between 96 and
127.
AAL2-G726-16 Payload
type Default value is 100. Range is from 96 to 127.
AAL2-G726 - 24
Payload type Default value is 99. Range is from 96 to 127.
AAL2-G726 - 32
Payload type Default value is 104. Range is from 96 to 127.
AAL2-G726 - 40
Payload type Default value is 103. Range is from 96 to 127.
G729E payload type Default value is 102. Range is from 96 to 127.
VAD Default is No. VAD allows detecting the absence of audio and conserve 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 Pass-Through (must use codec PCMU/PCMA)
Fax Tone Detection
Mode Default is Callee. This decides whether Caller, Callee or both sends out the re-INVITE
for T.38 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.
SRTP Mode This option defines different implementation of support SRTP (squired RTP)
transmission mode.
SLIC Setting Dependent on standard phone type (and location)
Caller ID Scheme Bellcore/Telcordia, ETSI-FSK, ETSI-DTMF, SIN 227 – BT, & NTT Japan
Polarity Reversal Default is No. If set to “Yes”, polarity will be reversed upon call establishment and
termination.
Loop Current
Disconnect Default is No. Set it to Yes if the traditional PBX you are using with HT502 uses this
method for signaling call termination. Method initiates short voltage drop on the line
when remote (VoIP) side disconnects an active call.