AudioCodes Mediant 800B MSBR User Manual page 342

Parameter
Web: Remote Renegotiate on Fax
Detection
CLI: sbc-rmt-renegotiate-on-fax-detect
[IPProfile_SBCRemoteRenegotiateOn
FaxDetection]
Mediant 800B MSBR
Description
Enables local handling of fax detection and negotiation by
the device on behalf of the SIP entity (to which the IP
Profile is assigned). This applies to faxes sent immediately
upon the establishment of a voice channel (i.e., after 200
OK).
The device attempts to detect the fax (CNG tone) from the
originating SIP entity within a user-defined interval (see
the SBCFaxDetectionTimeout parameter) immediately
after the voice call is established.
Once fax is detected, the device can handle the
subsequent fax negotiation by sending re-INVITE
messages to both SIP entities. The device also negotiates
the fax coders between the two SIP entities. The
negotiated coders are according to the list of fax coders
assigned to each SIP entity, using the IP Profile parameter
'Fax Coders Group ID'.

[0] Don't Care = (Default) Device does not interfere in
the fax transaction and assumes that the SIP entity
fully supports fax renegotiation upon fax detection.

[1] Only on Answer Side = The SIP entity supports fax
renegotiation upon fax detection only if it is the
terminating (answering) fax, and does not support
renegotiation if it is the originating fax.

[2] No = The SIP entity does not support fax re-
negotiation upon fax detection when it is the originating
or terminating fax.
Notes:

This feature is applicable only when both SIP entities
do not fully support fax detection (receive or send) and
negotiation: one SIP entity must be assigned an IP
Profile where this parameter is set to [1] or [2], while
the peer SIP entity must be assigned an IP Profile
where this parameter is set to [2].

This feature is supported only if at least one of the SIP
entities uses the G.711 coder.

This feature utilizes DSP resources. If there are
insufficient resources, the fax transaction fails.
342
Mediant 800B MSBR
Document #: LTRT-12813