Grandstream Networks HT502 user manual Vad

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	Default is Callee. This decides whether Caller, Callee or both sends out the re-INVITE
Mode	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	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	Default is No. Set it to Yes if the traditional PBX you are using with HT502 uses this
Disconnect	method for signaling call termination. Method initiates short voltage drop on the line
	when remote (VoIP) side disconnects an active call.
Loop Current	Here can be configured duration of such voltage drop described in topic above.
Disconnect Duration
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.
	If call volume is too low when using the FXS port (ie. the ATA is at user site), adjust
	volume using the Rx Gain Level parameter under the FXS Port Configuration page.
	If voice volume is too low at the other end, user may increase the far end volume using
	the Tx Gain Level parameter under the FXS Port Configuration page.
Disable Line Echo	Default is No. If set to “Yes” LEC will be disabled per call base. Recommended for
Canceller (LEC)	FAX/Data calls.
Ring Tones	This function lets you configure ring tone cadence preferences. User has 10 choices.
	The configuration, completed in Distinctive Ring Tones block in the same page, applies
	to ring tones cadences configured here.

Grandstream Networks, Inc.	HT-502 User Manual	Page 28 of 32
	Firmware Version 1.0.4.2	Last Updated: 06/2011