Our customer is using CUCM 6.1 with ATA186 and 2811 H.323 (12.4(9)T) Gateways with ISDN BRI. Now they have installed a Super G3 FAX which can not be reconfigured to G3 speeds. Calls from that Super G3 FAX to other Super G3 FAXes don't work as the ATA186 does not support Super G3. Hence we inserted a VIC2-2FXS card in the gateway and configured it for SCCP with the CUCM and T.38 with "fax-relay sg3-to-g3". The FAX calls from the Super G3 FAX to other Super G3 FAXes still fail (calls are disconnected after approx. 8 sec). I think the fax relay configuration is not really used because when the call is established there is no VoIP call leg, just the 2 POTS call legs.
Has anyone successfully connected a Super G3 FAX to an FXS port an was able to fax with other Super G3 FAXes over a ISDN interface on the same gateway?
If so, please let me now.
Many thanks in advance
My understanding is that SG3 is not supported under fax-relay/T38 only under passthrough. As SG3 uses special tones standard fax pass-through doesn't recognise the setup so you need modem passthrough. I hope that this helps. There is a very good fax book produced by Cisco Press - do you have Safari?