I have a network design where the remote LAN / FAX machines are connected to the WAN router only by fibre. Hence it was proposed to use the ATA186 device to connect the analogue FAX machine to the IP network. Only problem is that the WAN access which has been dimensioned for 100kbps of G729a voice (24k per call) is busted by a single fax = 80kbps !!! the problem just gets worse for remote WAN sites which have more than one FAX device.
Question. Is there any other device Cisco or not that I can use inplace of the ATA186 which has G.711 codecs. I need FAX to be sent at 24kbps FOIP for transport over the MPLS WAN where 100kbps COS1 b/w is configured. I do not have the ability to connect the FAX via copper to the WAN router (1760-V) as its location is served by a fibre IP link hence why PSTN is not an option either. If a cheap extra router can perform the FAX integration this would be fine however it does need to be in the same ballpark as an ATA186
I am not sure If I can be much help here but you may want to check out vg248 or another cisco router which may have couple of fxs ports and able to support cisco fax-relay. Once you find a box that can do cisco fax-relay increase the payload to 40 Byte and set fax rate to 9600 this configuratioin would bring down bandwidth to 24Kbps or lower for single fax call.
Hope that helps..