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We have an issue with the following. Any assistance would be greatly appreciated.

We have SIP trunks that terminate on our Call Manager which is 7.1.3.  We take the call from the SIP trunk (Remote DID) and then "translate" that number to a local 4 digit number that is associated with RIGHT FAX.  We can hear FAX tone, however RIGHT FAX shows that there are transmission errors.  I have setup a SIP profile and selected "Outgoing T.38 INVITE include audio mline".  I understand that this should causes the to switch the call from audio to T.38 fax.

David Hailey


I saw your post and just wanted to put this out there.  Things may have changed with RightFax supported deployment models but back a few years ago, I worked with a RightFax 9x deployment.  At the time, I had to do the RightFax 1 week training course as well as my own research on how to best deploy the product for the company I worked for at that time.  There were really only 3 supported deployment models that I remember:

1) T.38 fax relay where all communications with the fax server  is IP.  SIP comes into play here because a PSTN gateway is typically  configured to talk directly to the fax server and this communication is  SIP.  If you need to route calls to CCM and the fax server, then H.323 was used for CCM connectivity (presumably, this could become SIP now).

2) Direct T1 connection(s) to  RightFax.  No SIP. This doesn't apply to you.

3) MGCP Cisco Fax Relay.  Call signaling  for fax calls routes thru CCM via MGCP.  May not apply on the surface but could depending on the call flow (see below).

I will assume you are going to fall into the category of deployment model 1 where you have SIP trunks that come into a PSTN gateway.  So, my question would be are you translating the DID to a 4-digit pattern on the gateway or is the call routing thru the CUCM for translation and then back out to RightFax?  In the first model, the typical deployment is that patterns for faxing are routed directly from the gateway to RightFax via a SIP dial peer.  The CUCM is not involved in the fax process.

However, deployment 3 is a bit different.  This is where you want to route incoming fax calls to CUCM and then utlimately to/from RightFax.  At the time I worked on RightFax, you needed to use MGCP for this.

Now, SIP has come a long way since then and you may be doing most everything (if not everything) right.  My point is that you may need to verify if the deployment model is supported and then go from there.

For more details, go here:

and check out the Installation Guide supplement for Cisco Fax Server.


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