North American Network Operators Group
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: who gets a /32 [Re: IPV6 renumbering painless?]

  • From: Stephen Sprunk
  • Date: Sat Nov 20 22:57:25 2004 
Thus spake "Barney Wolff" <[email protected]>
Perhaps it is time to replace TCP with SCTP, where multihoming is not
incompatible with PA addressing. If done as a socket shim, so applications
don't have to be aware of it unless they want to be, it would appear to
solve all of these problems.

How much would it add to the pain of the v4-v6 transition, to just bite
the bullet and do tcp-sctp at the same time? I'd sure rather be a
network troubleshooter going through that than living with NAT forever.
Almost no host OSes support SCTP today, which is the major barrier; it took a decade to get IPv6 widely implemented in hosts, and there's no reason to think SCTP implementation would be as fast or faster.

That aside, SCTP sockets and TCP sockets are not created the same way nor behave the same way from the application's view. An API change would be needed to make this transparent to apps. Also, there's no way for one host to know if another supports SCTP _and_ is running SCTP-capable apps without actually attempting a connection, which costs time.

It seems easier to try to back-port SCTP's multihoming features to TCP somehow than to deploy an entirely new transport protocol. It's unfortunate this wasn't addressed at the time IPng was being designed.

S

Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking