Grandstream Networks HT801 Administration Manual page 37

iLBC Payload type Determines payload type for iLBC. Valid range is between 96 and 127. Default is 97.
OPUS Payload Type Determines payload type for OPUS. Valid range is between 96 and 127. Default is 123.
VAD Allows detecting the absence of audio and conserves bandwidth by preventing the
transmission of "silent packets" over the network. Default is No.
Symmetric RTP Changes the destination to send RTP packets to the source IP address and port of the
inbound RTP packet last received by the device. Default is No.
Fax Mode Specifies the fax mode : T.38 (Auto Detect) FoIP by default, or Pass-Through (must use
codec PCMU/PCMA)
Permits the unit to send out the re-INVITE for T.38 or Fax Pass Through if a fax tone is
Re-Invite after Fax
Tone Detection detected. Default is Enabled
Mode
Jitter Buffer Type Selects jitter buffer type (Fixed or Adaptive) based on network conditions.
Jitter Buffer Length
SRTP Mode Selects SRTP mode to use ("Disabled", "Enabled but not forced", or "Enabled and
forced"). Default is Disabled.
It uses SDP Security Description to exchange key. Please refer to
SDES:
Crypto Life Time Adds crypto life time header to SRTP packets. Default is Yes.
SLIC Setting Depends on standard phone type (and location).
Selects the caller id scheme, for example : Bellcore/Telcordia, ETSI-FSK ...
Caller ID Scheme
Defines the start and stop tones.
DTMF Caller ID
Polarity Reversal Reverses the polarity upon call establishment and termination. Default is No.
Loop Current Allows the traditional PBX used with HT801 to apply this method for signaling call
termination. Method initiates short voltage drop on the line when remote (VoIP) side
Disconnect
disconnects an active call. Default is No.
Configures the duration of voltage drop described in topic above. HT801 supports a
Loop Current
Disconnect duration range from 100 to 10000 ms. Default value is 200.
Duration

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).
https://tools.ietf.org/html/rfc4568
HT801 Administration Guide
/ SRTP: https://www.ietf.org/rfc/rfc3711.txt
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