That is normal behaviour if double RR is enabled in the RR module; two Record-Routes will be added if Kamailio is multihomed and the invite exits a different interface to the one it entered.

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Alex Balashov | Principal | Evariste Systems LLC
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Sent from my BlackBerry.
From: Mickael Marrache
Sent: Tuesday, May 5, 2015 08:27
To: sr-users@lists.sip-router.org
Reply To: Kamailio (SER) - Users Mailing List
Subject: [SR-Users] Double record routes

Hi,

 

We are adding TCP support to our load balancer and for some reason it adds two record route headers.

 

The instance have two IP addresses on which it binds: one if the VIP address and the second is the non-VIP address.

 

I explicitly set the tcp_source_ipv4 parameter with the VIP address so that it is used as source address for outbound TCP connection.

 

So, we get the following INVITE going from the load balancer to a proxy:

 

T 2015/05/05 12:08:49.715822 VIP:54667 -> PROXY:5060 [AP]

INVITE sip:123@mycompany.com SIP/2.0.

Record-Route: <sip:NONVIP;transport=tcp;r2=on;lr>.

Record-Route: <sip:VIP;transport=tcp;r2=on;lr>.

Via: SIP/2.0/TCP NONVIP;branch=z9hG4bK6f4.688efa90a17e02181ef7a11fecf8bb72.0;i=3.

Via: SIP/2.0/TCP 1.1.1.1:4598;received=2.2.2.2;branch=z9hG4bKmqFaCxNo6m3f5LW4;rport=40020.

 

You can see the INVITE is sent from the VIP address (as specified using the tcp_source_ipv4 parameter). However, the added Via corresponds to the non-VIP address. Also, you can see the two record route headers added for both addresses.

 

Any idea?

 

Thanks,

Mickael