Re: Dual registration without Outbound
Dean Willis <[email protected]>
| Newsgroups | gmane.ietf.sip |
|---|---|
| Message-ID | <[email protected]> |
On Oct 7, 2008, at 4:41 PM, Paul Kyzivat wrote: > > > The question is: why would a *single* UA establish two distinct > contacts and register them for the same AOR? > Because it has two different network interfaces, with two separate IP addresses, and it wants to use them both in case one of those contacts fails. Keepalive is then used so that the proxy-registrar can note a failed Contact. This is the classic dual-homed node use case, and it affects everything from DNS entries to BGP route advertisement. It's a general thorn in the sides of people who think of networks as acyclical graphs or trees. Sometimes, leaf nodes have multiple stems for good reasons. >> And, as you say, the edge proxies may be "access network >> dependent", so >> it may not even be possible to e.g. register the wlan contact via >> the 3g >> edge proxy, etc. > > So you are saying that the contact addresses are themselves access > network dependent??? So that the ip address of the contact is only > accessible via a particular access network and proxy? > > This *really* isn't the internet, is it!!! This isn't just a registration problem. Imagine an enterprise that's connected to two ISPs. Each ISP provides an SBC for the enterprise. Now you need two sets of telephone-routing tables to reach that enterprise. -- Dean _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [email protected] for questions on current sip Use [email protected] for new developments on the application of sip