target="NewWindow">draft-jennings-sipping-outbound-01
Often with SIP a request can only be
routed over an existing connection or flow, such as when there is a firewall or
network address translation (NAT) device in the network path. TLS is also
affected when the user agent (UA) does not have a certificate suitable for
mutual TLS authentication. This draft addresses how user agents and proxies need
to behave to work in these
environments.
routed over an existing connection or flow, such as when there is a firewall or
network address translation (NAT) device in the network path. TLS is also
affected when the user agent (UA) does not have a certificate suitable for
mutual TLS authentication. This draft addresses how user agents and proxies need
to behave to work in these
environments.
This work shows
how existing SIP mechanisms can be used to allow the UA to register multiple
times over different connections or flows and the proxies can use the
instance-id in the contact header to identify that the multiple flows go to the
same UA. It can then choose which flow to use to route requests to this
UA.