Use the Codec Entry - Fax window to configure options for a selected Codec Entry that specify how to handle fax tones when they are detected.

On the SBC main screen, go to Configuration > Profile Management > Category: Media Profiles > Codec Entry > Fax or
All > Profiles > Media > Codec Entry > Fax

The Fax window opens. Select a Codec Entry from the drop-down list to view and edit its fax parameters. Be aware that not all codec entries are based on codecs that support fax parameters. 

Figure 1: Codec Entry - Fax Window

Use the following table to edit the fax parameters and then click Save.

Table 1: Codec Entry - Fax Parameters

Parameter

Description

Failure
Handing

Specifies the behavior when a fax tone is detected but the treatment fails for any reason. The behavior can be:
• Disconnect—Release the call.
• Continue (default)—Continue to process the call.

Tone Treatment

Specifies the treatment taken when fax tones are detected, which can be:

  • Disconnect—Disconnect the call when fax tones are detected. 
  • Fallback To G711—Fall back to G.711 when fax tones are detected.
  • Fallback To G711Allow Peer To Negotiate Fax Relay —On detecting fax tones, the SBC initiates signalling of  transcoded calls to transition to G.711. This happens when the current codec is not already G.711. After transitioning to G.711, the SBC allows the peer to re-INVITE to T.38.
  • Fax Relay—Switch to fax relay (T.38) when fax tones are detected.
  • Fax Relay Or Fallback To G711—Switch to fax relay (T.38) if supported, or fall back to G.711 when fax tones are detected.
  • Ignore Detection Allow Peer To Negotiate Fax Relay—Accept a T.38 re-INVITE (either from a calling party or a called party) without detecting the fax tone.
  • None (default)—Do nothing when fax tones are detected.
  • Notify Peer—For SIP signaling, notify the peer when fax tones are detected and let the peer decide the next action.


Honor Tone Detection

Enable this option for G.711 to G.711 transcoded calls to cause the SBC to initiate a fax re-INVITE upon fax tone detection when the  Tone Treatment configuration is either Fax Relay Or Fallback To G711 or Fallback To G711.

When disabled, the SBC ignores the fax tone.

  • Disable (default)
  • Enable

This option only applies to a G.711 codec without silence suppression.

Note:

For G.711 calls, Notify Peer, Disconnect, Fax Relay, and Fax Relay or Fallback to G.711 require a compression resource to be allocated.




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