Getting Hangup on Fax Line - Help with log entry

Distro Discussion & Help
1

Fax seems to not connect. One item, notice comment re G729.

2

You cannot receive nor send Faxes over g729, it needs 64kbs uncompressed (g711), even then it relies on the robustness of both your and your VSP’s network

3

Trying to figure out why it is trying to use G729, Is it the trunk using 729 or am I missing some setting. I don’t have 729 checked under SIP Settings.

4

Check the trunk,'s allow/disallow, if not a problem call the provider.

5

You nailed it. I had forgotten that setting exists. Now, since we may want to use G729 on a trunk and we may have fax calls over that trunk in addition to voice calls, should the fax feature be capable of coping and switching to ulaw or whatever to coexist? Should I post this as a bug/request?

6

Also, what is the relationship between the SIP Setting of G729 and the trunk setting of G729? Are the independent?

7

Asterisk will negotiate the first mutually acceptable codec on both legs, by the sequence of your ordered list on both devices. I believe that FAX detection in SIP will re-request g711 if it is available. but for reliable transmission I suggest you use use T38.

8

Oh. I just looked for info on setting up T38 and wasn’t able to discover how to set it up.
Do I add T38 to the Trunk list or what?

9

Given that you self admitted that you “touch Linux so seldom that we forget most of what little we ever knew about Linux.” you probably need to go with a commercial solution. I believe the Sangoma FaxPRO will cover basic FAX to email and vice versa needs.

10

Fax, for our business, is a dying technology. We just use the PBX so we can avoid paying for a dedicated line. I am happy with the functionality, just want it to work. It has been working.

I still wonder how to mix FAX and voice on the same trunk if we want to use G729.

11

Asterisk will negotiate the first mutually acceptable codec on both legs, by the sequence of your ordered list on both devices. I believe that FAX detection in SIP will re-request g711 if it is available. but for reliable transmission I suggest you use use T38.

and

Given that you self admitted that you “touch Linux so seldom that we forget most of what little we ever knew about Linux.” you probably need to go with a commercial solution. I believe the Sangoma FaxPRO will cover basic FAX to email and vice versa needs.

No dedicated line involved, but you gotta read the manual (Sangoma is the new Schmooze if you missed that bit). . . .