Please help me understand the reason and source of this behaviour on Kamailio.

I receive a 200OK to a RE-INVITE that has : 

Session Name (s) : MySession

Connection Information (c) : IN IP4 xxx.xxx.xxx.xxx

Then, Kamailio routes the 200OK to it's destination, and it leaves Kamailio like this : 

Session Name (s) : MySession sdpc=IN xxx.xxx.xxx.xxx

The line Connection Information got deleted and it's info is now on  Session Name. How can i disable this ? 

Thanks