[SR-Users] Kamailio 4.4 with 2 Asterisk 13

I'm trying to load balance 2 Asterisk servers with Kamailio offloading the registration to Kamailio using the Asterisk real-time database tables. I have a problem with the dispatcher module, if there is a t_on_failure route it always goes into that, if I remove that then I would expect every call to round robin but I'm only ever hitting the same server from the same extension (seems like sticky session based on source ip). 1. how do I fix my failure route so I can reboot server 1 and server 2 will be used 2. how to I change the sticky session behaviour. Another issue I am facing with extensions registering to Asterisk are only avaliable on the server they routed to My assumption was if using the Asterisk real-time database I would get the contact on both servers. Maybe my architecture is incorrect, I'm open to suggestions. Currently Kamailio is not storing locations (assuming that is the extension contact) maybe that is a better solution, but I dont know how to configure Asterisk to forward everything to Kamailio then or integrate via the database or something. Thanks in advance for any help Regards Graham