As I can see a lot of people have problems with mgcp fax relay unfortunately none of the suggeted configs helped till now.
I have a CM 7 , 2x3845 12.4(24)T, 2xVg224 12.4(24)T. The gateways are registered in CM as MGCP.
My current config looks like this:
ccm-manager redundant-host 10.xx.xx.x 10.xx.x.x
no ccm-manager fax protocol cisco
ccm-manager config server 10.xx.xx.x 10.xx.xx.x
mgcp call-agent 10.xx.xx.x 2427 service-type mgcp version 0.1
mgcp dtmf-relay voip codec all mode cisco
mgcp modem passthrough voip mode nse
mgcp package-capability rtp-package
mgcp package-capability sst-package
mgcp package-capability pre-package
mgcp default-package fxr-package
no mgcp timer receive-rtcp
mgcp sdp simple
mgcp fax rate 14400
mgcp fax t38 ecm
mgcp fax-relay ans-disable
Thank you for your help.
Normally the 'latest and greatest' is a good idea. The problem is sometimes there are new bugs in those versions that are not fixed yet. This is one of those cases.
I would download 12.4(15)T9 onto your MGCP gateway and try this again. The configuration looks correct.
Also, please check 'show controller t1' (or e1) and check for slips. If you have slips you have likely forgotten to use the 'network-clock-select 1 t1 0/0/0' command. If you have slips and that command present, you may have a wiring/provider issue.