Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Fax transmission problem

We have a PC with a modem that is connected to a VG248 port. This PC has the Symantec Winfax application to send faxes. Anyone has experience with this app, modem and VG? It is not possible to send fax through the WAN (G729 codec) and it is not able either to send fax to another fax in different company but also connected to a VG248.

Any idea?

The VG port configuration:

Fax Relay: Disable

Passthrough: automatic

The gateway configuration:

mgcp modem passthrough voip codec g711alaw

mgcp fax t38 inhibit

Super Bronze

Re: Fax transmission problem


Are you saying that you CAN fax other outside phones, but NOT one in another company (via the PSTN) that uses CallManager?

Also if it's a PC check the speed it is faxing at and cut it down to 14400 if possible...

I'd check these things first:


Set on the ports:

Fax Relay:Disable

Passthrough:passthru only ECAN disable

Advanced settings:

Signalling type - IOS

On your MGCP gateway:

no ccm-manager fax protocol cisco

mgcp fax t38 inhibit

mgcp modem passthrough voip mode NSE

mgcp modem passthrough voip codec g711a (or 711u if that's what you use)


please rate helpful posts

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!
New Member

Re: Fax transmission problem

Thank you for the suggestions. I will change the passthrough setting to only ECAN disable.

Signalling type is already IOS.

On the MGCP the only parameter I din´t have is

no ccm-manager fax protocol cisco

but I can´t add it as the rest of faxes use Cisco fax relay

CreatePlease login to create content