Have user is experiencing problems transferring a fax call from their Cisco 7965 handset to our Rightfax server. Call is passed via H.323 gateway. Both H.323 gateways include the following fax entries in their config;
There is an incoming call from the PSTN going through an H.323 gateway to CUCM to a user's IP phone. The user then transfers the call to the Rightfax server by transferring the call to an extension. This transfer results in a call being directed out the same or a different H.323 Gateway. So, we have PSTN -> H.323 GW -> CUCM -> H.323 GW -> Rightfax. Is this correct?
I think it would be helpful to see why it is failing. Can you turn on debug messages on the H.323 gateways? Specifically, the H.245 debug messages. It would be useful to see what each gateway is proposing and whether CUCM might be manipulating the capability negotiation in some way. If you cannot turn on debugs directly on the Gateway, an Ethereal trace would work fine.
With that information, perhaps we can get an indication as to what might be causing the failure. I'm curious to know if the switch to T.38 is really made or if perhaps the fax is transmitted over G.729.