I have two voice gateways (2811 and VG224), both configured with MGCP. I am not using the "ccm-manager config server" command, to stop CM from configuring the gateway.
I placed a fax call between both gateways, controlled with a CM 5.1(2)b. The fax call completes successful everytime and under "show voice call sum" it indicates that the fax protocol is T.38.
---- Update
Gateway to Gateway MGCP T.38 is supported... according to this link:
http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1839/products_feature_guide09186a0080106902.html
