T38 setup issue

FreePBX
1

Hi all. First time trying to get T38 working with a Canon ADV-4545 with the T38 board and although it register to the extension I created just fine, trying to send a t38 fax results in nothing happening. According to tcpdump the printer doesn’t even try. The only communication I see is the following error. Is this a compatibility issue or is there more I need to do with Asterisk?

Reliably Transmitting (no NAT) to 192.168.2.116:5060:
OPTIONS sip:192.168.2.116:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.2.11:5060;branch=z9hG4bK1fbedab5
Max-Forwards: 70
From: “Unknown” sip:[email protected];tag=as3a5f71fc
To: sip:192.168.2.116:5060
Contact: sip:[email protected]:5060
Call-ID: [email protected]:5060
CSeq: 102 OPTIONS
User-Agent: FPBX-13.0.195.26(13.21.1)
Date: Thu, 21 Feb 2019 20:42:58 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH, MESSAGE
Supported: replaces, timer
Content-Length: 0

<— SIP read from UDP:192.168.2.116:5060 —>
SIP/2.0 405 Method Not Allowed
Via: SIP/2.0/UDP 192.168.2.11:5060;branch=z9hG4bK1fbedab5
Call-ID: [email protected]:5060
From: “Unknown” sip:[email protected];tag=as3a5f71fc
To: sip:192.168.2.116:5060;tag=774106469
CSeq: 102 OPTIONS
Content-Length: 0
Allow: INVITE,ACK,CANCEL,BYE,PRACK,UPDATE

<------------->
— (8 headers 0 lines) —
Really destroying SIP dialog ‘[email protected]:5060’ Method: OPTIONS

2

Your device doesn’t support the OPTIONS method. Those are the only ones it supports. So you’ll need to turn off Qualify to stop that.

3

Ok thanks. That was simple enough. Of course now all’s quiet from the printer… except for a successful registration.

4

So I found that the printer requires “VOIP Gateway Priority” to be set before it will decide how to route the job. Added that and now it attempts to send via Asterisk but the request is rejected as unauthorized. Does a special context have to be defined to allow a t38 call?

16:36:22.872574 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto UDP (17), length 628)
192.168.2.116.5060 > 192.168.2.11.5060: SIP, length: 600
INVITE sip:[email protected] SIP/2.0
Via: SIP/2.0/UDP 192.168.2.116:5060;branch=z9hG4bKs1ec2b681f
Max-Forwards: 70
Call-ID: [email protected]
From: sip:[email protected];tag=2861519808
To: sip:[email protected]
CSeq: 1 INVITE
Allow: INVITE,ACK,CANCEL,BYE,PRACK
Contact: sip:192.168.2.116:5060
Supported: 100rel,timer
Min-SE: 300
Session-Expires: 300
Content-Type: application/sdp
Content-Length: 135

    v=0
    o=- 2025817460 2025817460 IN IP4 192.168.2.116
    s=-
    c=IN IP4 192.168.2.116
    t=0 0
    m=audio 5004 RTP/AVP 0
    a=rtpmap:0 PCMU/8000

16:36:22.872952 IP (tos 0x60, ttl 64, id 63816, offset 0, flags [none], proto UDP (17), length 565)
192.168.2.11.5060 > 192.168.2.116.5060: SIP, length: 537
SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP 192.168.2.116:5060;branch=z9hG4bKs1ec2b681f;received=192.168.2.116
From: sip:[email protected];tag=2861519808
To: sip:[email protected];tag=as4015072c
Call-ID: [email protected]
CSeq: 1 INVITE
Server: FPBX-13.0.195.26(13.21.1)
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH, MESSAGE
Supported: replaces, timer
WWW-Authenticate: Digest algorithm=MD5, realm=“asterisk”, nonce=“1cd0d4d2”
Content-Length: 0

5

To follow up, after disabling the qualify option, setup was relatively easy. Fact is the device was not attempting to send due to the VoIP Gateway Priority not being setup. Seems kind of stupid with only one server but this device, the Canon iR-ADV 4545 and probably all ImageRunners, requires it. RTFM to the rescue! After that, it was a matter of reading the SIP responses and adjusting my config accordingly. The final issue was having to set insecure=invite before a fax was successfully transmitted. Thanks and catch ya later!

6

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