[SR-Users] How does kamailio keep track of contacts?

[Isaac McDonald]

Hello,

I'm having trouble understanding how Kamailio keeps track of contacts 
when used as an outbound proxy. When using Kamailio as the registrar, 
contact information for each endpoint is generally stored in the 
locations table.

However, when Kamailio is used as an outbound proxy, the location table 
isn't used to keep track registrations. How then does Kamailio keep 
track of contacts when used as an outbound proxy? Is Kamailio able to do 
NAT pinging on clients behind NAT in this scenario?

Thanks,

Isaac