[sr-dev] [kamailio] RR: Fail detecting strict routing (#267)

[antonioreale]

Scenario:
U1 (caller) ---> P1 (192.168.0.245, kamailio 4.3, loose-router) ----> P2 ----> (192.168.0.101, strict router) ----> .... ----> U2 (called)

When U2 answers the call, at P1 arrives the 200 OK with:
Record-Route: <sip:0000000011 at 192.168.0.101;transport=udp;pgw-call=call-28d2e>
Record-Route: <sip:192.168.0.245;lr=on>

The problem is that the ACK from U1 is forwarded from kamailio to P2, as if P2 is a loose router. P2 drops the ACK message.

>From kamailio logs I see:
`Jul 14 10:07:44 P1 /usr/sbin/kamailio[15908]: DEBUG: rr [loose.c:88]: is_preloaded(): is_preloaded: No
Jul 14 10:07:44 P1 /usr/sbin/kamailio[15908]: DEBUG: rr [loose.c:783]: after_loose(): Topmost route URI: 'sip:192.168.0.245;lr=on' is me
Jul 14 10:07:44 P1 /usr/sbin/kamailio[15908]: DEBUG: rr [loose.c:869]: after_loose(): URI to be processed: 'sip:0000000011 at 192.168.0.101;transport=udp;pgw-call=call-289ce'
Jul 14 10:07:44 P1 /usr/sbin/kamailio[15908]: DEBUG: rr [loose.c:878]: after_loose(): Next URI is a loose router
`

The Route HF in the ACK with the URI of the next hop does not contain ;lr .
It seems that the function is_strict fails detecting the strict router. 

Below the ACK received by U1:

`#
U 172.26.130.235:44435 -> 192.168.0.245:5060
ACK sip:7240F8EF-55A4D642000CBC22-8A135700 at 172.16.0.21;transport=udp SIP/2.0
Via: SIP/2.0/UDP 172.26.130.235:44435;branch=z9hG4bK-d8754z-1cd3a01fa9171649-1---d8754z-
Max-Forwards: 70
Route: <sip:192.168.0.245;lr>
Route: <sip:0000000011 at 192.168.0.101;transport=udp;pgw-call=call-28d2e>
Contact: <sip:0000000010 at 172.26.130.235:44435;transport=UDP>
To: <sip:0000000011 at 192.168.0.245;transport=UDP>;tag=516145211
From: <sip:0000000010 at 192.168.0.245;transport=UDP>;tag=a56ac352
Call-ID: NGU5YmUzMGYwM2RmMzc0YTQyNDRmZWZlOWJmMTA0ZjY.
CSeq: 2 ACK
Proxy-Authorization: Digest username="0000000010",realm="192.168.0.245",nonce="VaTXblWk1kKUxIMJBdWbpRBBCP850QVR",uri="sip:0000000011 at 192.168.0.245;transport=UDP",response="1daf03c97b8a12e0154d463f543e5592",algorithm=MD5
User-Agent: Z 3.6.25251 r25476
Content-Length: 0
`

and this the ACK forwarded by Kamailio to P2

`#
U 192.168.0.245:5060 -> 192.168.0.101:5060
ACK sip:7240F8EF-55A4D642000CBC22-8A135700 at 172.16.0.21;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.0.245;branch=z9hG4bKa252.cc67d8b538d8ad5c01c3e75d472653ec.0
Via: SIP/2.0/UDP 172.26.130.235:44435;branch=z9hG4bK-d8754z-1cd3a01fa9171649-1---d8754z-
Max-Forwards: 69
Route: <sip:0000000011 at 192.168.0.101;transport=udp;pgw-call=call-28d2e>
Contact: <sip:0000000010 at 172.26.130.235:44435;transport=UDP>
To: <sip:0000000011 at 192.168.0.245;transport=UDP>;tag=516145211
From: <sip:0000000010 at 192.168.0.245;transport=UDP>;tag=a56ac352
Call-ID: NGU5YmUzMGYwM2RmMzc0YTQyNDRmZWZlOWJmMTA0ZjY.
CSeq: 2 ACK
Proxy-Authorization: Digest username="0000000010",realm="192.168.0.245",nonce="VaTXblWk1kKUxIMJBdWbpRBBCP850QVR",uri="sip:0000000011 at 192.168.0.245;transport=UDP",response="1daf03c97b8a12e0154d463f543e5592",algorithm=MD5
User-Agent: Z 3.6.25251 r25476
Content-Length: 0
`

Thanks. Regards.

Antonio

---
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/267
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