Cisco Fax Server (Captaris) and Cisco Fax Relay

Unanswered Question
May 19th, 2009

Hello all!

i know that Captaris Cisco Fax Server works well with T.38 Fax Relay...and what about Cisco Fax Relay? Is it compatible?



I have this problem too.
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Overall Rating: 4 (2 ratings)
testeven Tue, 05/19/2009 - 10:13


Please check the following link, specially Pg. 9 "ISDN/MGCP Cisco Fax Relay Mode" . You'll see the deployment models of the Cisco Fax server: IP T.38 Fax Relay, ISDN E1/T1 Direct Connection and ISDN/MGCP Cisco Fax Relay Mode:

*** Installation Guide Supplement for Cisco Fax Server ***

Hope this helps!



If it helps, please rate! :)

Nicholas Matthews Tue, 05/19/2009 - 12:34

Hi Met,

Cisco fax relay is a proprietary fax method, and while Cisco Fax Server has the word Cisco in it, it is designed/maintained by RightFax. Thus, it does not support Cisco Fax Relay.

It's a legacy method anyhow, and T38 is much more preferred.


metalium2007 Tue, 05/19/2009 - 13:21


So can't I send faxes from FXS connected normal fax machines using fax relay in the gateways to the fax server?


Nicholas Matthews Tue, 05/19/2009 - 21:19

Hi Met,

You can, you just use T38:

voice service voip

fax protocol t38 fallback none

The only restriction is you can't fax to SCCP controlled FXS ports. MGCP will have:

no mgcp fax t38 inhibit

mgcp package fxr




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