Faxing over the WAN

[kevin.sullivan]

I am running centralized callmanagers supporting about 40 locations. I would like to fax between locations using the WAN. What is the best way to accomplish this?

We are running g.729 site to site for voice calls. What is the best way to accomplish this?

Callmangers are running 3.3.3

We are using 2651 router using frame relay as Primary route

We are using 3745 router using T1 as secondary route

Any help would be appreciated

[Aaron Harrison]

Basically you could use any router with spare capacity for DSPs/VICs and add some FXS ports, or you could use some ATA devices... there's lots of choices that will depend how many fax machines you require etc...

In terms of configuration you will definately need to be using G711 for fax calls or they will fail so your WAN/CAC must be able to accomodate the extra bandwidth.

Depending on your endpoints the support for the various fax-over-ip methods will vary but fax passthru support seems to be fairly universal. This basically just sets up a G711 call with any fancy features disabled (i.e. VAD etc) - aside from this you'll want to disable ECM mode on your fax machines.

There are lots of documents around outlining various configurations for fax... this doc lists the various devices you can use (the choice will is yours)...

http://www.cisco.com/en/US/tech/tk652/tk777/tech_tech_notes_list.html