Dear List

In the last week I try to figure out how I can put in place a configuration that use an edge proxy and a register by using kamailio 5.6, but i am facing some issues.

Scenario:

We are using on ubuntu 20.04, HAproxy and Kamailio 5.6.

We have configured a Kamailio register that, in the following case, perfectly works.

                             ______ __               __________
                   TLS               |              |     TLS        |              |
Client ------------------ > | NAT     |-----------> | Kamalio  |
                         in |_HAProxy | out      in | Register |
                            |_________|             |          |
                                                    |________ _|

Now we want to put a kamailio edge proxy before the kamailio Register, please take a look to the below picture

                             ______

                             ______ __              _________                  ___________
                   TLS               |              |     TLS        |             |        TCP         |                |
Client ------------------ > | NAT     |-----------> | Kamalio | -------------> | Kamailio  |
                         in |_HAProxy | out      in | Edge    | out         in | Register  |
                            |_________|             | Proxy   |                |           |
                                                    |_________|                |___________|

HAproxy -> sip-test.example.com

Kamailio edge proxy -> 192.168.58.1

Kamailio  Register     -> 192.168.58.15

The kamailio Edge has been configured as indicated in the outbound module example.


When a transaction such as REGISTER or SUBSCRIBE reach the "Kamailio Register" the Record-Route and Via headers are correct and it works.


When the transaction such as MESSAGE or INVITE reach the "Kamailio Register" it does not work and below you can see the message and the error.

Note that the Record-Route and Via headers are the same as the previous message REGISTER and SUBSCRIBE.


Dec  6 11:57:09 qcast-webserver-dev /usr/sbin/kamailio[15340]: INFO: {1 40742 MESSAGE YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET} <script>: SIPMessage-in-request = 192.168.58.1:53606-sip:s-user.02@sip-dev.example.com-MESSAGE sip:s-user.02@sip-dev.example.com SIP/2.0

Record-Route: <sip:192.168.58.1:15006;transport=tcp;r2=on;lr>
Record-Route: <sip:sip-test.example.com:16005;transport=tls;r2=on;lr>
Via: SIP/2.0/TCP 192.168.58.1:15006;branch=z9hG4bKa257.add27f134dd83c78aef13ca7798f87ca.0;i=6
Via: SIP/2.0/TLS 192.168.58.1:39592;received=192.168.58.1;rport=39592;branch=z9hG4bKPjajkY.0NlW2AFuz3.BRaKH4EdvdmQTs9L;alias
Max-Forwards: 69
From: <sip:s-user.03@sip-dev.example.com>;tag=VnOekkKsq4tLhFAywXzbxLXxIesWscn3
To: <sip:s-user.02@sip-dev.example.com>
Call-ID: YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET
CSeq: 40742 MESSAGE
Accept: text/plain, application/im-iscomposing+xml
Content-Type: text/plain
Content-Length:    59

################## MESSAGE ###################
Dec  6 11:57:09 qcast-webserver-dev /usr/sbin/kamailio[15340]: INFO: {1 40743 MESSAGE YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET} <script>: SIPMessage-in-request = 192.168.58.1:53606-sip:s-user.02@sip-dev.example.com-MESSAGE sip:s-user.02@sip-dev.example.com SIP/2.0
Record-Route: <sip:192.168.58.1:15006;transport=tcp;r2=on;lr>
Record-Route: <sip:sip-test.example.com:16005;transport=tls;r2=on;lr>
Via: SIP/2.0/TCP 192.168.58.1:15006;branch=z9hG4bKb257.83b972054df1675806975159ae1f1e43.0;i=6
Via: SIP/2.0/TLS 192.168.58.1:39592;received=192.168.58.1;rport=39592;branch=z9hG4bKPjfan-Tte.vtL8brkWb20wm.5b8iuVEtQV;alias
Max-Forwards: 69
From: <sip:s-user.03@sip-dev.example.com>;tag=VnOekkKsq4tLhFAywXzbxLXxIesWscn3
To: <sip:s-user.02@sip-dev.example.com>
Call-ID: YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET
CSeq: 40743 MESSAGE
Accept: text/plain, application/im-iscomposing+xml
Proxy-Authorization: Digest username="s-user.03", realm="sip-dev.example.com", nonce="Y48hMWOPIAW7JeSQ7/a+cuJ1gKwT8hrC", uri="sip:s-user.02@sip-dev.example.com", response="3b7c34476443e5f1125fa460a4981180", cnonce="3AT-ZMwyfpgaMwlulh5cq5vJHi75-wnz", qop=auth, nc=00000001
Content-Type: text/plain
Content-Length:    59


Dec  6 11:57:09 qcast-webserver-dev /usr/sbin/kamailio[15340]: WARNING: {1 40743 MESSAGE YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET} <core> [core/forward.c:228]: get_send_socket2(): protocol/port mismatch (forced tcp:192.168.58.15:15006, to tls:192.168.58.1:60982)
Dec  6 11:57:09 qcast-webserver-dev /usr/sbin/kamailio[15340]: ERROR: {1 40743 MESSAGE YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET} tm [ut.h:315]: uri2dst2(): no corresponding socket found for "192.168.58.1" af 2 (tls:192.168.58.1:60982)
Dec  6 11:57:09 qcast-webserver-dev /usr/sbin/kamailio[15340]: ERROR: {1 40743 MESSAGE YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET} tm [t_fwd.c:471]: prepare_new_uac(): can't fwd to af 2, proto 3  (no corresponding listening socket)
Dec  6 11:57:09 qcast-webserver-dev /usr/sbin/kamailio[15340]: ERROR: {1 40743 MESSAGE YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET} tm [t_fwd.c:1754]: t_forward_nonack(): failure to add branches
Dec  6 11:57:09 qcast-webserver-dev /usr/sbin/kamailio[15340]: ERROR: {1 40743 MESSAGE YsfZ7Rq-WGw33NUn9AFMWEuurzryvzET} sl [sl_funcs.c:372]: sl_reply_error(): stateless error reply used: I'm terribly sorry, server error occurred (7/SL)


based on what we have understood in the message headers "Via" and Record-Route" there are the right information to reach back the proxy Edge, but looking to the error message it seems that the kamailio register try to reach back the proxy edge through the TLS instead of using the TCP.


Could someone put me in the right direction.

Thanks

Regards

--

Ing. Giovanni Iamonte
Developments and technologies area
Quintetto Srl
Via Monte Navale, 1
10015 - Ivrea (TO)
 mobile: +39 393 9196310
 tel: +39 0165 1845290
 e-mail: giovanni.iamonte@quintetto.it
 web: www.quintetto.it