AudioCodes Mediant 2600 - Fax Negotiation and Transcoding; Limiting SBC Call Duration

Version 6.8 335 Mediant 2600 E-SBC
User's Manual 20. SBC Overview
20.5 Fax Negotiation and Transcoding
The device can allow fax transmissions to traverse transparently without transcoding or it
can handle the fax as follows:

Allow interoperability between different fax machines, supporting fax transcoding if
required.

Restrict usage of specific fax coders to save bandwidth, enhance performance, or
comply with supported coders. These coders include G.711 (A-Law or Mu-Law), VBD
(G.711 A-Law or G.711 Mu-Law), and T38.
Fax configuration is done in the IP Profile and Coder Group Settings tables. The IP Profile
table determines the supported fax coders and the negotiation method used between the
incoming and outgoing fax legs, using the following fax-related parameters:

SBCFaxBehavior: defines the offer negotiation method - pass fax transparently,
negotiate fax according to fax settings in IP Profile, or enforce remote UA to first
establish a voice channel before fax negotiation.

SBCFaxCodersGroupID: defines the supported fax coders (from the Coders Group
Settings table).

SBCFaxOfferMode: determines the fax coders sent in the outgoing SDP offer.

SBCFaxAnswerMode: determines the fax coders sent in the outgoing SDP answer.

IPProfile_SBCRemoteRenegotiateOnFaxDetection: You can also configure the device
to detect for faxes (CNG tone) immediately after the establishment of a voice channel
(i.e., after 200 OK) and within a user-defined interval. If detected, it can then handle
the subsequent fax renegotiation by sending re-INVITE messages to both SIP entities
(originating and terminating faxes). For more information, see the parameter in
Configuring IP Profiles on page
297.
Note: The voice-
related coder configuration (Allowed and Extended coders) is
independent of the fax-related coder configuration, with the exception of the G.711
coder. If the G.711 coder is restricted by the Allowed Coders Group table, it is not
used for fax processing even if it is listed in the Coders Group Settings table for faxes.
However, support for G.711 coders for voice is not dependent upon which fax coders
are listed in the Coders Group Settings table.
20.6 Limiting SBC Call Duration
You can define a maximum allowed duration (in minutes) for SBC calls. If an established
call reaches this user-defined limit, the device terminates the call. This feature ensures
calls are properly terminated, allowing available resources for new calls. This feature is
configured using the MaxCallDuration parameter.