Solved Fax Server Issues - 488 Not Acceptable Here

[Michael Menor]

Hi everyone,

We're pretty new to the 3CX Fax Server feature and we can't seem to get this (simple) feature to work. All we need is for Fax to Email to work. I opened up a support case with 3CX and they state that the trunk provider will need to support T.38 on their end. I've confirmed with two of the three providers that we've tested with that they are T.38 capable, so far we've tested with CallCentric, Voip.ms (not T.38 capable), and BabyTel.

We are on V15 SP3 (15.0.60903.0)

Each time I test a fax, this is what I get in the Activity Log:

12/30/2016 1:19:30 PM - L:235.2[Fax:888] Sending: OnSendResp Send 488/INVITE from 0.0.0.0:0 tid=3164b524a509d23d Call-ID=MqXqt7y2QxZ_NfOSDRU1Xw..: SIP/2.0 488 Not Acceptable Here Via: SIP/2.0/UDP 127.0.0.1:5483;branch=z9hG4bK-524287-1---3164b524a509d23d;rport=5483 To: <sip:[Incoming Fax Number]@[Our 3CX FQDN]:5060;nf=e>;tag=e81e812a From: <sip:888@[Internal 3CX IP]:5060;user=fax>;tag=f258bf33 Call-ID: MqXqt7y2QxZ_NfOSDRU1Xw.. CSeq: 2 INVITE Content-Length: 0

Any input in this matter would be greatly appreciated.

 

[leejor]

Check to see what Codecs are defined for use along the path. You should probably be using g711a/u, anything "low bit rate" is going to have a problem.

 

[Michael Menor]

We're just using the default bit rate "14400". I also have g.711a first, then g.711u in priority. I also tried swapping them. No joy.

 

[cobaltit]

So based on the build, you are on SP4 not SP3. This is important because 3CX changed the fax server in SP4. I have an open ticket with 3CX regarding the fax server as a customer that fax worked fine on SP3 broke with SP4. I rolled it back to SP3 for now but will be going back to SP4 to Wireshark so they can further troubleshoot

 

[Michael Menor]

@cobaltit Just curious, are you using the Linux version? We're using the Windows version. How did you roll it back to SP3?

 

[cobaltit]

I'm using the Linux version in my office, but the problem I'm troubleshooting was with the Windows version for one of my customers. To roll it back I just uninstalled and reinstalled from a download of SP3 I had and restored a backup.

 

[N_G]

You should check with your provider if fax is even enabled. Babytel definitely supports fax with 3cx

 

[Michael Menor]

@Nick Galea Babytel does support fax with 3CX. I have tested it on V14 SP3 with no issues, but it will not work in V15 (as noted above). So far, 3CX Support hasn't been much of a help in resolving the fax server issues that we've been having with V15.

 

[exevi]

Hi All,

I can confirm the same fax problem, “488 not acceptable here”, in v15 SP3 and SP4. Incoming calls finish after 1 second.
VoIP provider has confirmed T38 support.

Tested from different sources, such as physical fax machines, and some fax test providers in Internet.
Tested also changing Codec order priority g711a/u in SIP Trunk.

Any idea to solve the problem, or do you think is a 3CX bug?
Thanks in advance,

Partial Trace:


01/02/2017 3:39:13 PM - [CM503008]: Call(C:6): Call is terminated
01/02/2017 3:39:13 PM - L:6.2[Fax:888]: Terminating targets, reason: SIP ;cause=200 ;text="Call terminated on user request"
01/02/2017 3:39:13 PM - Reported(Delete): SE:6.2{OnHook}
01/02/2017 3:39:13 PM - StatusNotification: SE:6.2{OnHook}; Skip=0
01/02/2017 3:39:13 PM - Blocking refers for the Call(C:6)
01/02/2017 3:39:13 PM - Call(C:6) is terminated
01/02/2017 3:39:13 PM - Call(C:6): Legs count: 1
01/02/2017 3:39:13 PM - Stop call record for leg L:6.1[Line:10000<<anonymous]
01/02/2017 3:39:13 PM - Removing leg L:6.1[Line:10000<<anonymous]
01/02/2017 3:39:13 PM - L:6.1[Line:10000<<anonymous]: Terminating targets, reason: SIP ;cause=200 ;text="User hangup"
01/02/2017 3:39:13 PM - Leg L:6.1[Line:10000<<anonymous] is terminated: Cause: BYE from local
01/02/2017 3:39:13 PM - Reported(Delete): SE:6.1{OnHook}
01/02/2017 3:39:13 PM - StatusNotification: SE:6.1{OnHook}; Skip=0
01/02/2017 3:39:13 PM - L:6.1[Line:10000<<anonymous] got Terminated Send Req BYE from 0.0.0.0:0 tid=b273b6224e78ca7a Call-ID=cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000:
BYE sip:[email protected]:5060;transport=udp SIP/2.0
Via: SIP/2.0/ ;branch=z9hG4bK-524287-1---b273b6224e78ca7a;rport
Max-Forwards: 70
Route: <sip:195.42.6.32;lr>
Route: <sip:195.42.3.17;lr;ftag=4if2x3g0-CC-34>
Route: <sip:195.42.6.32;lr>
Contact: <sip:[email protected]:5060>
To: Anonymous <sip:[email protected]>;tag=4if2x3g0-CC-34
From: <sip:[email protected];user=phone>;tag=b5792c47
Call-ID: cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000
CSeq: 3 BYE
User-Agent: 3CXPhoneSystem 15.0.60903.0 (60821)
Reason: SIP;text=Application Rejected Sdp(usually no common codec)
Content-Length: 0

01/02/2017 3:39:13 PM - L:6.1[Line:10000<<anonymous] Sending: OnSendReq Send Req BYE from 0.0.0.0:0 tid=2d30c76030440b58 Call-ID=cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000:
BYE sip:[email protected]:5060;transport=udp SIP/2.0
Via: SIP/2.0/ ;branch=z9hG4bK-524287-1---2d30c76030440b58;rport
Max-Forwards: 70
Route: <sip:195.42.6.32;lr>
Route: <sip:195.42.3.17;lr;ftag=4if2x3g0-CC-34>
Route: <sip:195.42.6.32;lr>
Contact: <sip:[email protected]:5060>
To: Anonymous <sip:[email protected]>;tag=4if2x3g0-CC-34
From: <sip:[email protected];user=phone>;tag=b5792c47
Call-ID: cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000
CSeq: 3 BYE
Reason: SIP;text=Application Rejected Sdp(usually no common codec)
Content-Length: 0

01/02/2017 3:39:13 PM - Offer is rejected on Leg L:6.1[Line:10000<<anonymous];
OnOfferRejected Recv 488/INVITE from 195.42.6.32:5060 tid=e919f6051052c229 Call-ID=cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000:
SIP/2.0 488 Not Acceptable Here
Via: SIP/2.0/UDP 192.168.1.10:5060;received=214.1.12.22;branch=z9hG4bK-524287-1---e919f6051052c229;rport=5060
To: Anonymous <sip:[email protected]>;tag=4if2x3g0-CC-34
From: <sip:[email protected];user=phone>;tag=b5792c47
Call-ID: cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000
CSeq: 2 INVITE
Content-Length: 0

01/02/2017 3:39:13 PM - L:6.1[Line:10000<<anonymous] Sending: OnSendReq Send Req INVITE from 0.0.0.0:0 tid=487b314fd514324d Call-ID=cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000:
INVITE sip:[email protected]:5060;transport=udp SIP/2.0
Via: SIP/2.0/ ;branch=z9hG4bK-524287-1---487b314fd514324d;rport
Max-Forwards: 70
Route: <sip:195.42.6.32;lr>
Route: <sip:195.42.3.17;lr;ftag=4if2x3g0-CC-34>
Route: <sip:195.42.6.32;lr>
Contact: <sip:[email protected]:5060>
To: Anonymous <sip:[email protected]>;tag=4if2x3g0-CC-34
From: <sip:[email protected];user=phone>;tag=b5792c47
Call-ID: cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000
CSeq: 2 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE
Content-Type: application/sdp
Supported: replaces
Content-Length: 344

v=0
o=3cxPS 543061704704 350056611842 IN IP4 214.1.12.22
s=3cxPS Audio call
c=IN IP4 214.1.12.22
t=0 0
m=image 9014 udptl t38
c=IN IP4 214.1.12.22
a=T38FaxVersion:0
a=T38FaxRateManagement:transferredTCF
a=T38MaxBitRate:14400
a=T38FaxMaxBuffer:1800
a=T38FaxMaatagram:150
a=T38FaxMaxIFP:40
a=T38FaxUdpEC:t38UDPRedundancy
01/02/2017 3:39:12 PM - L:6.1[Line:10000<<anonymous] Sending: OnSendResp Send 200/INVITE from 0.0.0.0:0 tid=7cf3.d64055f5649208b6ae290f2e357cfb78.0 Call-ID=cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000:
SIP/2.0 200 OK
Via: SIP/2.0/UDP 195.42.6.32;branch=z9hG4bK7cf3.d64055f5649208b6ae290f2e357cfb78.0
Via: SIP/2.0/UDP 195.42.3.17;rport=5060;branch=z9hG4bK7cf3.ba58738fd4e02d9d513b0e09e80226b3.0
Via: SIP/2.0/UDP 195.42.6.32;rport=5060;branch=z9hG4bK7cf3.9466f2ffd96517ac3be2520857283c51.0
Via: SIP/2.0/UDP 212.106.213.5:5060;rport=5060;branch=z9hG4bKr1bkp930e820s01mj710.1
Record-Route: <sip:195.42.6.32;lr>
Record-Route: <sip:195.42.3.17;lr;ftag=4if2x3g0-CC-34>
Record-Route: <sip:195.42.6.32;lr>
Contact: <sip:[email protected]:5060>
To: <sip:[email protected];user=phone>;tag=b5792c47
From: Anonymous <sip:[email protected]>;tag=4if2x3g0-CC-34
Call-ID: cggc20ca0k1xadiei3xxgdb4e03c103c@SoftX3000
CSeq: 1 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE
Content-Type: application/sdp
Supported: replaces
User-Agent: 3CXPhoneSystem 15.0.60903.0 (60821)
Content-Length: 297

v=0
o=3cxPS 543061704704 350056611841 IN IP4 214.1.12.22
s=3cxPS Audio call
c=IN IP4 214.1.12.22
t=0 0
m=audio 9012 RTP/AVP 8 0 18 97
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=yes
a=rtpmap:97 telephone-event/8000
a=fmtp:97 0-15
a=sendrecv
01/02/2017 3:39:12 PM - Providing SDP for L:6.1[Line:10000<<anonymous]
01/02/2017 3:39:12 PM - Reneg. from L:6.2[Fax:888], offer
01/02/2017 3:39:12 PM - Leg L:6.2[Fax:888] raised event RecvdRemoteSdp
01/02/2017 3:39:12 PM - Remote SDP is set for leg L:6.2[Fax:888]
01/02/2017 3:39:12 PM - Offer SDP arrived on Leg L:6.2[Fax:888];
OnOffer Recv Req INVITE from 127.0.0.1:5483 tid=de30f34ccb7fd20a Call-ID=PYUNIumqFzz104ggTnM42A..:
INVITE sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 127.0.0.1:5483;branch=z9hG4bK-524287-1---de30f34ccb7fd20a;rport=5483
Max-Forwards: 70
Contact: <sip:[email protected]:5483;rinstance=2f14986c9560a069>
To: "Anonymous:Entrada FAX"<sip:[email protected]:5060;nf=e>;tag=eb54e86a
From: <sip:[email protected]:5060;user=fax>;tag=a7114f7b
Call-ID: PYUNIumqFzz104ggTnM42A..
CSeq: 2 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE
Content-Type: application/sdp
Supported: replaces
User-Agent: 3CX Fax
Content-Length: 325

 

[nb]

We have made a test with Babytel on V15 Sp4 and it works.. (for us it worked - I received a fax)

Look from the logs 3CX rejects the call because of SDP (no matching codec). So the reason is pretty clear - no matching codec. More details require a wireshark capture of the flow.. Fax is very low level and not all logs are dumped because if we do this, there will be pages of logs for a single fax page.

So what I would normally do, is to go to the persons that have the COMPLETE RECORD of the call - in this negotiation you should go to the provider and ASK them why it is not working or what they see wrong in this. (Maybe it is some settings that can be provisioned - either by you from your portal or from the provider. )

We checked with our babytel account and ours worked. But ours can be different, provisioned differently or using even different servers so I would contact them first.

 

[exevi]

Thanks a lot for your quick response Nicky.
I will follow your suggestion, and let you know the response.

King Regards,

 

[Michael Menor]

@exevi Would you mind sending me your 3CX ticket so I may reference it in my ticket?

 

[exevi]

Hi Michael,

Sorry, No 3CX ticket has been opened. I will check traces with my VoIP provider first, as Nicky said.
Regards,

 

[Michael Menor]

@nickybrg I just disabled our Babytel trunk on V14 and enabled it again on V15, but it is still not working. I opened a case with Babytel and I'm awaiting a response from them.
I have the same SIP provider settings in V14 and V15. I receive a "fax tone" on V14, but not on V15.

 

[nb]

on the side until the provider answers, go to custom parameter table, find FAXLOGGINGLEVEL and set to 3.

Stop IVR Service.
Go to the logs folder and DELETE all IVR logs.
Then start ivr service. the logs will be verbose and fresh just from what you do from this point onwards.
Then replicate this problem.
After we can check what is happening.
Are you sure the did or inbound destination is going to the fax service?

 

[Michael Menor]

@nickybrg The rep that's assigned to our ticket just requested those settings and I sent him the Wireshark trace and Support Info files. (PM me if you would like the Case #)

We have an Inbound rule to fax to my extension's email address. We also tested it with the default 888 Fax Server extension with no luck.

 

[nb]

cc me in babytels email conversation - I have some questions to ask them too..
Or you can ask them what in the 3CX SDP they dont like..
Is it this "Media Attribute (a): T38FaxMaxIFP:40"
because it should be 40 as per rfc but from past experience, we learnt that some providers want it undeclared in the sdp.
This non mandatory feature might be not declared and if it is declared, it will become mandatory for that transaction and if the provider does not like it, it will fail. - this is the only thing we could find suspicious in your report. But without their confirmation it is going to be very painful to test and reproduce..

As I said before, It is always good to ask them (who are the server in this case) and we become a client.. All the answers and transactions are recorded by the provider and they can check the flow and why the server is rejecting this.
Strange thing that we tested again with our test account and faxes came in like a breeze.. We will await more info from your side..

 

[Michael Menor]

@nickybrg We received a response to our 3CX ticket and it "may" be a bug... (the details were vague)

 

[nb]

Actually I was about to answer..
Make the following test:

1. Stop IVR
2. Download a debug patch from here: http://downloads.3cx.com/downloads/support/faxpatch2017/3CXIVR.exe
3. Go to C:\Program Files\3CX Phone System\Instance1\Bin and rename 3CXIVR.exe to 3CXIVR_prod.exe
4. Put the downloaded 3CXIVR.exe (this is a debug non rfc compliant patch so we do not stay waiting for the providers answer on this one)
5. Start IVR
6. Make a test.
Try and see if it works. Let me know asap. ciao..

 

[Michael Menor]

@nickybrg You are a savior! That worked! I replied to the 3CX ticket with a few questions though.

01/04/2017 7:57:50 AM - L:16.2[Fax:888] Sending: OnSendResp Send 200/INVITE from 0.0.0.0:0 tid=6a05c5693652ae74 Call-
ID=APe__dDXpiDwpxQQAQv-qw..:
SIP/2.0 200 OK
Via: SIP/2.0/UDP 127.0.0.1:5483;branch=z9hG4bK-524287-1---6a05c5693652ae74;rport=5483
Contact: <sip:[Phone number]@127.0.0.1:5060>
To: "Unavailable"<sip:[Phone number]@[FQDN]:5060;nf=e>;tag=f5503435
From: <sip:101@[PBX IP]:5060;user=fax>;tag=e9602c7e
Call-ID: APe__dDXpiDwpxQQAQv-qw.. CSeq: 2 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE
Content-Type: application/sdp
Supported: replaces
Content-Length: 301
v=0
o=3cxPS 448572424192 330460823554 IN IP4 127.0.0.1
s=3cxPS Audio call
c=IN IP4 127.0.0.1
t=0 0 m=image 7482 udptl t38
a=T38FaxVersion:0
a=T38MaxBitRate:14400
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaxBuffer:262
a=T38FaxMaatagram:176
a=T38FaxUdpEC:t38UDPRedundancy a=sendrecv