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Protocol-based T.38 FoIP Integration

We are having the hardest time coming up with a GOOD solution to integrate our fax server into our CUCM 6.1 (will be 8.5 in the future) environment.

We are using Omtool's AccuRoute product for our network-based faxing solution.  For fax over IP, they recommend the Dialogic SR140 which supports T.38 (presumably protocol-based) and fax pass-through.  OmTool has not had good experience with fax pass-through so they will not support it.  This leaves us with protocol-based T.38 as the only integration option.

Our analog environment is made up of ~650 SCCP FXS endpoints (VG224s) spread across one large HQ site and a dozen smaller remote sites.  We chose SCCP for the call-control protocol to maintain as much feature parity with the Centrex that we migrated the HQ site away from, and because we wanted to re-use our analog conference sets.  These conference sets need to be able to initiate meet-me calls plus we have requirements to support call pickup groups for other analog endpoints.  We are currently using NSE-based fax passthrough as our FoIP standard but we are at a point where we could convert to NSE-based T.38.

Are there any good solutions for integrating a protocol-based T.38 fax server into this environment?  We would like to be able to maintain the ability to send/receive faxes between a SCCP-controlled FXS endpoint and our fax server.  Converting our analog environment to H.323, SIP, or MGCP are not options because we need the features provided by SCCP.  We approached our account team with this dilemna and they recommended a hybrid approach where only our fax ports would be converted to H.323, SIP, or MGCP.  However, they were not able to provide any official documentation for this approach which makes us and our client uneasy over its supportability.

Anyone have any thoughts or suggestions?

Daniele Giordano
Rising star

Cisco doesn't support the "T.38" to "G.711 pass through" transcode natively. The only way is T.38 -> TDM loop (e.g. T1 or E1 loop) -> G.711 NSE pass through.

I've implemented this solution many years ago without problem.

I've an H.323 T.38 fax server interconnected to a CISCO IAD 2431 with a E1 loop which converts faxes in SIP - G.711 NSE pass through.


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