received fax is cut off

[bit101]

Hi togehter,

we have from time to time the situation that incoming faxes are cut off. The page is only half there and the rest is simply cut off.
I dont know at the moment if the faxes are coming in with G.711 or T.38. This i have to check but do you know what we can do?
The parameter FAX_PCMU_T38_FALLBACK_TIMEOUT is already set to 20 seconds and now to 30 seconds. But i dont think
that this would create a remedy.
The Siptrunk forwards unchanged the T.38 and G.711 protocols to 3CX.

regards
bit101

3CX Version 18.0.3.461

 

[VasilisV_3CX]

Hi @bit101,

Can you confirm if it is G.711 or T.38? It's important for us to know.

Also, who is your provider?

 

[bit101]

Hi Vasilis,

most of them comes via G.711 like you can see here, also the Sip Trunk Provider:

Invite-IN Recv Req INVITE from 195.185.37.60:5060 tid=zvNVeaSRMd0ty Call-ID=SBC5ea60c002629-624eedec-44c9df15-32329218-2713248-01_b2b-1:

INVITE sip:[email protected]:5060;rinstance=f23a32e887fdd336 SIP/2.0

Via: SIP/2.0/UDP 195.185.37.60;branch=z9hG4bKzvNVeaSRMd0ty;rport=5060

Max-Forwards: 68

Contact: <sip:[email protected];transport=udp>

To: <sip:[email protected]>

From: <sip:[email protected]>;tag=1EFEE228-624EEDED00002BE6-24AB5700

Call-ID: SBC5ea60c002629-624eedec-44c9df15-32329218-2713248-01_b2b-1

CSeq: 10 INVITE

Allow: ACK, BYE, CANCEL, INVITE, OPTIONS, PRACK

Content-Type: application/sdp

Supported: histinfo

Content-Length: 221



v=0

o=- 614114416 1331665342 IN IP4 195.185.37.60

s=-

c=IN IP4 195.185.37.60

t=0 0

m=audio 22168 RTP/AVP 8 101

a=rtpmap:8 PCMA/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

a=sendrecv

a=direction:both

 

[VasilisV_3CX]

Hi @bit101,

What is receiving the fax? Is it a fax machine?

I'm afraid the above doesn't tell me much as all Fax calls start as telephone calls. Can you get a Verbose capture of a fax that has a part of the page cut off as you described?

From the Dashboard >> Activity Log >> Settings >> switch to Verbose. Now go back to the Activity Log and change the interfaces (where it says eth0 next to Capture) to "All Interfaces". Start the Capture and send the fax. When it's finished, download the dump file and send it to me via PM (upload it to something like google drive).