[OpenSIPS-Users] [nat_traversal] Replacement of bflag(NAT_CALLED) ?

Dan Pascu dan at ag-projects.com
Wed Nov 12 13:22:53 CET 2008

On Wednesday 12 November 2008, Iñaki Baz Castillo wrote:
> 2008/11/12 Klaus Darilion <klaus.mailinglists at pernau.at>:
> > I still do not understand. The callee has to be registered -
> > otherwise it is not reachable at all. Thus, keep-alive for the callee
> > will be done once it registers based on nat tests during REGISTER.
> > Thus, when calling the callee, the session is implicitly keep-alive'd
> > by the the keep-alive  triggered by registration. What do I miss?
> In case the callee ends its registration during the call,
> nat_traversal *still* sends NOTITY/OPTIONS to the callee until the
> call ends, even if the callee is not registered anymore.

In addition to that, there are also more complex cases involving networks 
having topologies with multiple proxies handling a given domain, which 
also need such a behavior. In short, not only can a registration end 
during a call, but also the NAT entry point used to renew a registration 
may change during a call.

All of this stuff is explained in pretty much detail in the README.


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