Grandstream HT502 User Manual - Manual (Page 48)

FIRMWARE VERSION 1.0.14.1 HT502 USER MANUAL Page 46 of 54
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.

High (initial 200ms, min 40ms, max 600ms) Note: not all vocoders can meet
the high requirement

Medium (initial 100ms, min 20ms, max 200ms)

Low (initial 50ms, min 10ms, max 100ms)
SRTP Mode Secure RTP protocol used for media transmission over VoIP. Disabled by default.
Other modes are: enabled but not forced & enabled and forced.
Crypto Life Time Default is Enabled. Allows user to enable or disable Crypto life time when using SRTP.
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.
Play busy/reorder tone
before Loop Current
Disconnect
Default is No. If set to Yes, it will play busy/reorder tone before loop current disconnect
upon call fail.
Loop Current
Disconnect Duration
Here can be configured duration of such voltage drop described in topic above.
Enable Hook Flash Default is Yes . If set to “No”, FLASH button could only be used for terminating calls.
Hook Flash Timing Time period when the cradle is pressed (Hook Flash) to simulate FLASH. To prevent
unwanted activation of the Flash/Hold and automatic phone ring-back, adjust this time
value.
On Hook Timing On-hook timing is the minimum time for an on-hook event to be validated.
Gain Voice path volume adjustment.
• Rx is a gain level for signals transmitted by FXS
• Tx is a gain level for signals received by FXS.
Default = 0dB for both parameters. Loudest volume: +6dB Lowest volume: -6dB.
User can adjust volume of call on either end using the Rx Gain Level parameter and
the Tx Gain Level parameter located on the FXS Port Configuration page.