3cx doesn't detect T38 media

[the.neon]

Hi ,

I have the problem that the sending of a fax doesn't work.
For me it looks that the 3cx doesn't detect the media switch to the T38 protocol.
The Gateway switch to the T38 :
m=image 31234 udptl t38
a=T38FaxVersion:3
a=T38MaxBitRate:33600
But the 3cx send to the voip client :
s=3cxPS Audio call
c=IN IP4 192.168.110.225

a audio signal .
Where is the problem ? I have a V10 System on the newest patch .

Best Regards

Daniel


Complete Log:
NVITE sip:[email protected]:5066 SIP/2.0
Via: SIP/2.0/UDP 192.168.110.250:9803;rport=9803;branch=z9hG4bK1100028672-330500756
Max-Forwards: 70
Contact: <sip:[email protected]:9803>
To: "92287" <sip:[email protected]:9803>;tag=6460cf3e
From: <sip:[email protected]:9803>;tag=sipcontrol_1095177672-330369684
Call-ID: MGI2NDU5ZTExYzM3Yjc4NGQ5YTk0ZjcwODI1ZjM3OTA.
CSeq: 2 INVITE
Session-Expires: 600;refresher=uac
Min-SE: 90
Accept: application/sdp, application/simple-message-summary
Allow: INVITE, ACK, CANCEL, BYE, OPTIONS, NOTIFY, REFER, PRACK
Content-Type: application/sdp
Supported: 100rel, replaces, timer
Content-Length: 402

v=0
o=SIPcontrol 165119306 165119311 IN IP4 192.168.110.250
s=-
c=IN IP4 192.168.110.250
t=0 0
m=audio 0 RTP/AVP 0 101
m=image 31234 udptl t38
a=T38FaxVersion:3
a=T38MaxBitRate:33600
a=T38FaxFillBitRemoval:0
a=T38FaxTranscodingMMR:0
a=T38FaxTranscodingJBIG:0
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaatagram:128
a=T38FaxMaxBuffer:284
a=T38FaxUdpEC:t38UDPRedundancy
a=sendrecv

20:53:43.843|.\TransactionUser.cxx(74)|Debug8|Resip|::ResipLogger:Match!
20:53:43.843|.\Helper.cxx(375)|Debug8|Resip|::ResipLogger:Helper::makeResponse(SipReq: INVITE [email protected]:5066 tid=1100028672-330500756 cseq=INVITE [email protected]:9803 / 2 from(wire) code=100 reason=
20:53:43.843|.\TimerQueue.cxx(85)|Debug8|Resip|::ResipLogger:Adding timer: Timer Trying tid=1100028672-330500756 ms=80
20:53:43.843|.\TransactionState.cxx(2112)|Debug8|Resip|::ResipLogger:Send to TU: TU: DialogUsageManager size=0

INVITE sip:[email protected]:5066 SIP/2.0
Via: SIP/2.0/UDP 192.168.110.250:9803;rport=9803;branch=z9hG4bK1100028672-330500756
Max-Forwards: 70
Contact: <sip:[email protected]:9803>
To: "92287" <sip:[email protected]:9803>;tag=6460cf3e
From: <sip:[email protected]:9803>;tag=sipcontrol_1095177672-330369684
Call-ID: MGI2NDU5ZTExYzM3Yjc4NGQ5YTk0ZjcwODI1ZjM3OTA.
CSeq: 2 INVITE
Session-Expires: 600;refresher=uac
Min-SE: 90
Accept: application/sdp, application/simple-message-summary
Allow: INVITE, ACK, CANCEL, BYE, OPTIONS, NOTIFY, REFER, PRACK
Content-Type: application/sdp
Supported: 100rel, replaces, timer
Content-Length: 402

v=0
o=SIPcontrol 165119306 165119311 IN IP4 192.168.110.250
s=-
c=IN IP4 192.168.110.250
t=0 0
m=audio 0 RTP/AVP 0 101
m=image 31234 udptl t38
a=T38FaxVersion:3
a=T38MaxBitRate:33600
a=T38FaxFillBitRemoval:0
a=T38FaxTranscodingMMR:0
a=T38FaxTranscodingJBIG:0
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaatagram:128
a=T38FaxMaxBuffer:284
a=T38FaxUdpEC:t38UDPRedundancy
a=sendrecv

20:53:43.843|.\Authorization.cpp(857)|Debug2||FindBlacklistEntry:EBL: IPBL found ip = 192.168.110.250; result = not found
20:53:43.843|.\DialogId.cxx(50)|Debug8|Resip|::ResipLoggerialogId:ialogId: MGI2NDU5ZTExYzM3Yjc4NGQ5YTk0ZjcwODI1ZjM3OTA.-6460cf3e-sipcontrol_1095177672-330369684
20:53:43.843|.\DialogUsageManager.cxx(1333)|Trace5|Resip|::ResipLogger:Got: SipReq: INVITE [email protected]:5066 tid=1100028672-330500756 cseq=INVITE [email protected]:9803 / 2 from(wire)
20:53:43.843|.\DialogUsageManager.cxx(1651)|Debug8|Resip|::ResipLoggerialogUsageManager:rocessRequest: SipReq: INVITE [email protected]:5066 tid=1100028672-330500756 cseq=INVITE [email protected]:9803 / 2 from(wire)
20:53:43.843|.\DialogUsageManager.cxx(1711)|Trace5|Resip|::ResipLogger:Handling in-dialog request: SipReq: INVITE [email protected]:5066 tid=1100028672-330500756 cseq=INVITE [email protected]:9803 / 2 from(wire)
20:53:43.843|.\DialogId.cxx(50)|Debug8|Resip|::ResipLoggerialogId:ialogId: MGI2NDU5ZTExYzM3Yjc4NGQ5YTk0ZjcwODI1ZjM3OTA.-6460cf3e-sipcontrol_1095177672-330369684
20:53:43.843|.\DialogSet.cxx(484)|Debug8|Resip|::ResipLogger:Found matching dialog mClientSubscriptions(0), mServerSubscriptions(0) for

INVITE sip:[email protected]:5066 SIP/2.0
Via: SIP/2.0/UDP 192.168.110.250:9803;rport=9803;branch=z9hG4bK1100028672-330500756
Max-Forwards: 70
Contact: <sip:[email protected]:9803>
To: "92287"<sip:[email protected]:9803>;tag=6460cf3e
From: <sip:[email protected]:9803>;tag=sipcontrol_1095177672-330369684
Call-ID: MGI2NDU5ZTExYzM3Yjc4NGQ5YTk0ZjcwODI1ZjM3OTA.
CSeq: 2 INVITE
Session-Expires: 600;refresher=uac
Min-SE: 90
Accept: application/sdp, application/simple-message-summary
Allow: INVITE, ACK, CANCEL, BYE, OPTIONS, NOTIFY, REFER, PRACK
Content-Type: application/sdp
Supported: 100rel, replaces, timer
Content-Length: 402

v=0
o=SIPcontrol 165119306 165119311 IN IP4 192.168.110.250
s=-
c=IN IP4 192.168.110.250
t=0 0
m=audio 0 RTP/AVP 0 101
m=image 31234 udptl t38
a=T38FaxVersion:3
a=T38MaxBitRate:33600
a=T38FaxFillBitRemoval:0
a=T38FaxTranscodingMMR:0
a=T38FaxTranscodingJBIG:0
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaatagram:128
a=T38FaxMaxBuffer:284
a=T38FaxUdpEC:t38UDPRedundancy
a=sendrecv

20:53:43.843|.\Dialog.cxx(370)|Debug8|Resip|::ResipLoggerialog::dispatch: SipReq: INVITE [email protected]:5066 tid=1100028672-330500756 cseq=INVITE [email protected]:9803 / 2 from(wire)
20:53:43.843|.\SipMessage.cxx(986)|Debug8|Resip|::ResipLogger:SipMessage::getContents: application/sdp
20:53:43.843|.\Helper.cxx(2131)|Debug8|Resip|::ResipLogger:Got sdp

20:53:43.843|.\InviteSession.cxx(2561)|Trace5|Resip|::ResipLogger:Transition InviteSession::Connected -> InviteSession::ReceivedReinvite
20:53:43.843|.\InviteADS.cpp(306)|Trace5||InviteADS:nOffer:Offer from <sip:[email protected]:9803>;tag=sipcontrol_1095177672-330369684 to "92287"<sip:[email protected]:9803>;tag=6460cf3e
20:53:43.843|.\CallLeg.cpp(410)|Trace5||CallLeg:nOfferArrived:OfferSDP arrived for session 125 of Leg C:2.2
20:53:43.843|.\CallLeg.cpp(1126)|Log5||CallLeg::setRemoteSdp:Remote SDP is set for legC:2.2
20:53:43.843|.\CallLeg.cpp(382)|Trace5||CallLeg::gotSdp:Leg C:2.2 raised event RecvdRemoteSdp
20:53:43.843|.\Call.cpp(847)|Trace5||Call::Renegotiate:Reneg. from C:2.2, offer
20:53:43.843|.\Call.cpp(963)|Trace5||Call::Renegotiateroviding SDP for C:2.1
20:53:43.843|.\MSInterface.cpp(688)|Trace5||??:MSLogReports
20:53:43.843|.\SLServer.cpp(832)|Log5|MediaServer|MediaServerReporting::SetRemoteParty:[MS210002] C:2.1:Offer provided. Connection(transcoding mode): 192.168.110.225:7004(7005)
20:53:43.843|.\ServerInviteSession.cxx(223)|Trace5|Resip|::ResipLogger:InviteSession::Connected: provideOffer
20:53:43.843|.\InviteSession.cxx(2561)|Trace5|Resip|::ResipLogger:Transition InviteSession::Connected -> InviteSession::SentReinvite
20:53:43.843|.\Dialog.cxx(1004)|Debug8|Resip|::ResipLoggerialog::makeRequest:

INVITE sip:[email protected]:5066 SIP/2.0
Via: SIP/2.0/ ;branch=z9hG4bK-d8754z-9e44f46fe2761b0b-1---d8754z-;rport
Max-Forwards: 70
Contact: <sip:[email protected]:5066>
To: <sip:[email protected]>;tag=fe1448c11
From: <sip:[email protected]>;tag=905a1c15
Call-ID: fe1448c119b56766
CSeq: 2 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE
Supported: replaces
Content-Length: 0


20:53:43.843|.\InviteSession.cxx(2220)|Trace5|Resip|::ResipLogger:InviteSession::SentReinvite: startStaleReInviteTimer
20:53:43.843|.\TimerQueue.cxx(105)|Debug8|Resip|::ResipLogger:Adding application timer: DumTimeout::StaleReInvite INVITE: 122 InviteSession::SentReinvite ADDR=<sip:[email protected]>;tag=905a1c15 PEER=<sip:[email protected]>;tag=fe1448c11: duration=40 seq=2
20:53:43.843|.\InviteSession.cxx(384)|Trace5|Resip|::ResipLogger:Sending SipReq: INVITE [email protected]:5066 tid=9e44f46fe2761b0b cseq=INVITE [email protected]:5066 / 2 from(tu)
20:53:43.843|.\InviteADS.cpp(272)|Trace5||InviteADS:nReadyToSend:SendMsg from <sip:[email protected]>;tag=905a1c15 to <sip:[email protected]>;tag=fe1448c11
20:53:43.843|.\CallLeg.cpp(755)|Debug2||CallLeg:nReadyToSend:Sending: SipReq: INVITE [email protected]:5066 tid=9e44f46fe2761b0b cseq=INVITE [email protected]:5066 / 2 from(tu)
20:53:43.843|.\Extension.cpp(1416)|Debug2||Extension::notifyDI:Ext.750: sip:[email protected]:5066, Call(2)
20:53:43.843|.\Extension.cpp(1433)|Debug2||Extension::notifyDI:Call(2): DlgID:2-1938, entry state: 2
20:53:43.859|.\DialogUsageManager.cxx(866)|Debug8|Resip|::ResipLogger:SEND:

INVITE sip:[email protected]:5066 SIP/2.0
Via: SIP/2.0/ ;branch=z9hG4bK-d8754z-ab22c40fc703c23a-1---d8754z-;rport
Max-Forwards: 70
Contact: <sip:[email protected]:5066>
To: <sip:[email protected]>;tag=fe1448c11
From: <sip:[email protected]>;tag=905a1c15
Call-ID: fe1448c119b56766
CSeq: 2 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE
Content-Type: application/sdp
Supported: replaces
User-Agent: 3CXPhoneSystem 10.0.19079.0
Content-Length: 303

v=0
o=3cxPS 500648902656 239008219138 IN IP4 192.168.110.225
s=3cxPS Audio call
c=IN IP4 192.168.110.225
t=0 0
m=audio 7004 RTP/AVP 0 3 8 101
c=IN IP4 192.168.110.225
a=rtpmap:0 PCMU/8000
a=rtpmap:3 GSM/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16
a=sendrecv

 

[lneblett]

Please define your scenario. It looks like you are trying to send from one extension and receive at another.

3CX itself is not setup to send faxes. The fax server is only set to receive. To send, you will need an appropriate ATA connected to a fax machines and both the ATA and your SIP provider must support T38. The fax will need to be configured as an extension. I am not aware of anyone having any real success with this, although there have been a few sporadic posts. From what I have seen, it seems like those who have had success seemingly were able to do so using pass thru mode using a G711 codec.

Hopefully others who have had some success in this area will provide more guidance, but my own experience in trying as well as the lack of those who have tried indicate that it not easy and when successful, not always reliable.

 

[the.neon]

Hi ,

my scenario is

SIP FaxSoftware ( DAVID) -> 3cx Fax Extension -> BRI GW

so the FaxSoftware will send through the 3cx a fax to external number .
The Problem I think is that the 3cx to FaxSoftware that the connection is a voice one and not T38 one.
So how can I force the 3cx to switch to an T38 connection ?

Regards

 

[lneblett]

As I indicated, 3CX does not in and of itself support the sending of faxes. The software you have will need to integrate with 3CX and provide the signaling and then your gateway must also support t38. Not knowing the specifics of either the software or gateway make it problematic to even guess what needs to be done.

However, go to the blog and enter in Relay Fax into the search. This is a software approach that reportedly is supported and does have t38 compatibilty. There might be enough information to glean from these posts that will steer you to a set-up solution for your scenario.

 

[RichardCrabb1]

It could be that it would be better if the fax software sent UDP packets straight to the BRI interface. Make sure that for both the FAX extension and the BRI gateway that PBX. Do this as follows:-
Go the the gateway and on the advanced tab uncheck PBX delivers audio. Check both "Support re-invite" and "supports replaces". This assumes that the gateway does support both. On the extension, do the same by going to the "other" tab and do the same. Let us know whether this works, as I am interested. I have used fax successfully using T.38 for inbound and outbound. Also, try reducing the speed to 14,400.

Richard

 

[SY]

Where is the problem ? I have a V10 System on the newest patch .

Configure 750 as a fax extension. It should resolve "3cx doesn't detect T38 media" problem for v10.
Transparent media delivery for video and t38 is available in v11.

 

[jpillow]

Configure 750 as a fax extension. It should resolve "3cx doesn't detect T38 media" problem for v10.
Transparent media delivery for video and t38 is available in v11.

Sy how would you configure that extension as fax extension? would simply changing the extension number in system extension status---> edit extension settings than chaning the extension from 888 to in this case 750 would resolve the isssue of "3cx doesn't detect T38 media" ? But in V11 this isnt necessary as at all? Thanks in advance

 

[rbc94]

in the management console, go to fax machines and click add fax extension.