Hello,

 

the ACK to a 200 OK is not part of the (previous) SIP INVITE transaction. Please refer to the standard for more details: https://datatracker.ietf.org/doc/html/rfc3261#section-17

 

Cheers,

 

Henning

 

--

Henning Westerholt – https://skalatan.de/blog/

Kamailio services – https://gilawa.com

 

From: sr-users <sr-users-bounces@lists.kamailio.org> On Behalf Of Linux Vince
Sent: Thursday, April 28, 2022 12:36 PM
To: Kamailio (SER) - Users Mailing List <sr-users@lists.kamailio.org>
Subject: [SR-Users] t_check_trans failed on ACK

 

I am using Kamailio as registrar and proxy for underlying asterisk server.

 

I am able to call but ACK on 200 OK respond from client phones are not validating transaction and thus not relaying correctly.

 

Below are my Invites and 200 OK responses. 

 

Invite from Asterisk to Kamailio

 

Via: SIP/2.0/UDP 65.20.69.72:5060;rport;branch=z9hG4bKd6ffff9d46ceb899c245ece204e51c87

From: "R31313005 N31313005" <sip:31313005@65.20.69.72:5060;user=phone>;tag=GR52RWG346-34

CSeq: 1 INVITE

Contact: <sip:65.20.69.72:5060>

max-forwards: 70

Allow: PUBLISH, SUBSCRIBE, MESSAGE, ACK, NOTIFY, OPTIONS, REFER, INFO, BYE, CANCEL, INVITE

Content-Type: application/sdp

Content-Length:   228

 

v=0

o=Clarent 155866 155867 IN IP4 65.20.69.72

s=Clarent CallManager

c=IN IP4 65.20.69.72

t=0 0

m=audio 45168 RTP/AVP 0 8 101

a=rtpmap:0 PCMU/8000

a=rtpmap:8 PCMA/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

 

 

Invite from Kamailio to Phone

 

INVITE sip:31313004@65.20.67.118;lhst=180.211.119.50:25759;lm=midreg SIP/2.0

Via: SIP/2.0/UDP 65.20.67.118;branch=z9hG4bK6cc3.dad7580d3e28f55cbb749dbb82f0c9eb.0

Via: SIP/2.0/UDP 65.20.69.72:5060;received=65.20.69.72;rport=5060;branch=z9hG4bKd6ffff9d46ceb899c245ece204e51c87

From: "R31313005 N31313005" <sip:31313005@65.20.69.72:5060;user=phone>;tag=GR52RWG346-34

CSeq: 1 INVITE

Contact: <sip:65.20.69.72:5060>

max-forwards: 69

Allow: PUBLISH, SUBSCRIBE, MESSAGE, ACK, NOTIFY, OPTIONS, REFER, INFO, BYE, CANCEL, INVITE

Content-Type: application/sdp

Content-Length:   228

 

v=0

o=Clarent 155866 155867 IN IP4 65.20.69.72

s=Clarent CallManager

c=IN IP4 65.20.69.72

t=0 0

m=audio 45168 RTP/AVP 0 8 101

a=rtpmap:0 PCMU/8000

a=rtpmap:8 PCMA/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

 

 

 

200 OK from Phone to Kamailio

 

SIP/2.0 200 OK

Via: SIP/2.0/UDP 65.20.67.118;received=65.20.67.118;branch=z9hG4bK6cc3.dad7580d3e28f55cbb749dbb82f0c9eb.0

Via: SIP/2.0/UDP 65.20.69.72:5060;rport=5060;received=65.20.69.72;branch=z9hG4bKd6ffff9d46ceb899c245ece204e51c87

From: "R31313005 N31313005" <sip:31313005@65.20.69.72;user=phone>;tag=GR52RWG346-34

To: "31313004@rigel.com" <sip:31313004@rigel.com>;tag=4ecc1f21f1544fd783965f27ff6d95d2

CSeq: 1 INVITE

Allow: PRACK, INVITE, ACK, BYE, CANCEL, UPDATE, INFO, SUBSCRIBE, NOTIFY, REFER, MESSAGE, OPTIONS

Supported: replaces, 100rel, timer, norefersub

Content-Type: application/sdp

Content-Length:   322

 

v=0

o=- 3860150297 3860150298 IN IP4 180.211.119.50

s=pjmedia

b=AS:84

t=0 0

a=X-nat:0

m=audio 4016 RTP/AVP 0 101

c=IN IP4 180.211.119.50

b=TIAS:64000

a=rtcp:4017 IN IP4 180.211.119.50

a=sendrecv

a=rtpmap:0 PCMU/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-16

a=ssrc:1461220511 cname:3b657c275d2a43f6

 

 

 

200 OK from kamailio to asterisk

 

SIP/2.0 200 OK

Via: SIP/2.0/UDP 65.20.69.72:5060;rport=5060;received=65.20.69.72;branch=z9hG4bKd6ffff9d46ceb899c245ece204e51c87

From: "R31313005 N31313005" <sip:31313005@65.20.69.72;user=phone>;tag=GR52RWG346-34

To: "31313004@rigel.com" <sip:31313004@rigel.com>;tag=4ecc1f21f1544fd783965f27ff6d95d2

CSeq: 1 INVITE

Allow: PRACK, INVITE, ACK, BYE, CANCEL, UPDATE, INFO, SUBSCRIBE, NOTIFY, REFER, MESSAGE, OPTIONS

Supported: replaces, 100rel, timer, norefersub

Content-Type: application/sdp

Content-Length:   322

 

v=0

o=- 3860150297 3860150298 IN IP4 180.211.119.50

s=pjmedia

b=AS:84

t=0 0

a=X-nat:0

m=audio 4016 RTP/AVP 0 101

c=IN IP4 180.211.119.50

b=TIAS:64000

a=rtcp:4017 IN IP4 180.211.119.50

a=sendrecv

a=rtpmap:0 PCMU/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-16

a=ssrc:1461220511 cname:3b657c275d2a43f6

 

ACK from phone to Kamailio

 

Via: SIP/2.0/UDP 65.20.69.72:5060;rport;branch=z9hG4bK111270de2729ade9e048afa0f9fbb8df

From: "R31313005 N31313005" <sip:31313005@65.20.69.72:5060;user=phone>;tag=GR52RWG346-34

To: "31313004@rigel.com" <sip:31313004@rigel.com>;tag=4ecc1f21f1544fd783965f27ff6d95d2

CSeq: 1 ACK

Contact: <sip:65.20.69.72:5060>

max-forwards: 70

Allow: PUBLISH, SUBSCRIBE, MESSAGE, ACK, NOTIFY, OPTIONS, REFER, INFO, BYE, CANCEL, INVITE

 

 

This ACK is failing on transaction check and not routing correctly to phone.

 

Any help?

 

Thanks