Configuring Rerouting Of Calls To Fax Destinations - AudioCodes Mediant 4000 SBC User Manual

User's Manual
Parameter

25.2.1 Configuring Rerouting of Calls to Fax Destinations

You can configure the device to reroute incoming SBC calls identified as fax calls to a new
IP destination. The device identifies a fax call if it detects, within a user-defined interval, a
calling (CNG) tone on the originator side (incoming IP leg). If the device detects a fax call, it
terminates the call and reroutes it using a new INVITE to the new fax destination (new IP
Group). If the initial INVITE that was used to establish the voice call was already sent, the
device sends a CANCEL (if not connected yet) or a BYE (if already connected) to release
the call (with the internal disconnect reason RELEASE_BECAUSE_FAX_REROUTING,
translated to Q.850 reason GWAPP_NORMAL_UNSPECIFIED 31).
Note:
•
You must configure the originating fax to use the G.711 coder.
•
If the remote side replies with T.38 or G.711 VBD, fax rerouting is not done.
•
If both fax rerouting and fax re-INVITE are configured, only fax rerouting is done.
The following procedure describes how to configure fax rerouting, using an example
consisting of three IP Groups.

To configure fax rerouting:
1. Configure the fax detection interval:
a. Open the Fax/Modem/CID Settings page (Setup menu > Signaling & Media tab
> Media folder > Fax/Modem/CID Settings).
b. In the 'Fax Detection Timeout' field (SBCFaxDetectionTimeout), enter the
duration (in seconds) for which the device attempts to detect fax (CNG tone):
2. Configure three IP Groups in the IP Groups table (see Configuring IP Groups on page
349):
•
IP Group #0 "HQ": This is the source IP Group, sending voice calls and fax calls.
•
IP Group #1 "Voice": This is the destination for voice calls sent from IP Group #0.
•
IP Group #2 "Fax": This is the destination for fax calls sent from IP Group #0.
3. For the fax destination (IP Group #2), do the following:
a. Configure a Coder Group with T.38, which allows fax transmission over IP (see
Configuring Coder Groups on page 409).
b. Configure an IP Profile (see Configuring IP Profiles on page 418):
♦
♦
Version 7.2
Server (SRS):
Redirect(response='302',contact='sip:'+header.to.ur
l.user+'@siprecording.com')
Note:

The parameter can be used for normal and alternative routing.

The response code for redirect messages can only be 3xx.
Assign it the Coder Group.
Configure the 'Fax Rerouting Mode' parameter to Rerouting without delay:
Description
511
25. Routing SBC
Mediant 4000 SBC