Hi, im new on this, and have no experience with fax operations.

I have a PBXIP and ATA FAXMachine, i set with G11a Alaw codec and making and receiving calls normally, when sending a fax, the machine does not send, it indicates that the process has failed.

Could you help me?
What information do you need my system?

Thank you.

Fax over IP is generally a terrible idea.
You should be using t.38 at a minimum. Other than that it is hours of tuning everything you can tune and you should expect 90% success if you get it perfect.

Are you using G.711 alaw all the way through from ATA to PBX and then to SIP service provider?

Yes, i using this configurations.
I can make a call normaly, but i can’t send a fax only.
The fax response is ‘comunication error’

what i making wrong?

I using Lixnux CentOS, and i have this versions and equipaments:

CentOS 6.5 (Final)
Asterisk 10.12.2, Copyright © 1999 - 2012 Digium, Inc. and others.
Khomp Model ebs channel 4.02
ATA - Linksys SPA
FaxMachine - Digital SPA

And i have a culpe of servers with ip’s: - PABX - DATABASE - Ringer - STORAGE - MEDIA GATEWAY

The ATA its set to PABX, and configured one RAMAL 1267.

Someone understand that?

Sorry I’m not with that at all. When you say:

ATA - Linksys SPA
FaxMachine - Digital SPA

I’m not sure if you mean the Fax is connected to a separate ATA or whether it’s connected to the Linksys ATA.

I’m not sure of the relevance of the different servers. And also I don’t know what RAMAL 1267 means.