Dear Support,
We are testing new cisco ATAs - SPA112 to replace SPA2102 which is out of sale. We never had fax issues with SPA2102, but now can't get T.38 working on new SPA112. Tried different settings, including recommeded in admin guide (section: "Optimizing Fax Completion Rates"), but nothing helped.
There is difference in receiving and sending faxes, but with stable results - sending fails, receiving - success, but with retransmissions and at lower speed. This is how it look like:
1. Sending:
- T.38 negotiation successful
- receiving (PSTN) side sends T.38 DIS messages three times, but SPA112 does not send back DCS message and does not start fax transmission.
- fax transmission fails
2. Receiving:
- T.38 negotiation successful
- DIS-DCS-Training procedure successful (14400b)
- first page received, but after MPS (multipage signal ) from sending side, SPA112 sends back RTN (retrain negative) every time
- procedure continues at 12000b, fails again
- procedure continues at 9600b, and this time successfully
- next pages transmitted at 9600b successfully.
Upgraded to v1.2.1, but nothing is changed.
Please find attached call analyis from wireshark - two calls incoming and outgoing.
Also please find attached fax config screenshot.
Best regards
Ivo
