[Serdev] usrloc loading

[Andreas Granig]

Greger V. Teigre wrote:
> Hi guys!
> I have taken the liberty to try to summarize your contributions, as well 
> as add my 2 cents here:
> http://www.iptel.org/failover_redundancy_and_scalability_overview

Great. Regarding your comment about NAT in the Pros of the second 
approach: NAT-traversal can be achieved by using variation 2 in the list 
(path-header). Since the path is stored in the location table, every 
proxy can route the message via the right path.

Additionally, you need a SIP loadbalancer which the NATed UAC 
communicates with, and every proxy has to route calls towards the UAC 
via this lb (using the path header). The lb of course has to be set up 
in a redundant way (active/backup), but since it only relays SIP 
messages back and forth, it can handle way more calls than the "work 
horses".