When Kamailio receives the INVITE, it relays it with two Record-Route like
this :
Record-Route:sip:IP1;ftag=xxxxxxxx;vst=xxxxxxx;vsf=xxxxxxx
Record-Route:sip:IP2;ftag=xxxxxxxx;vst=xxxxxxx;vsf=xxxxxxx
What i want is :
Record-Route:sip:IP1;ftag=xxxxxxxx;vst=xxxxxxx;vsf=xxxxxxx;NEW_PARAMETER=10
Record-Route:sip:IP2;ftag=xxxxxxxx;vst=xxxxxxx;vsf=xxxxxxx;NEW_PARAMETER=20
I hope this make sense now.
Thanks for your help