> For most people out there router is this thing connected to cable modem. Even if it's technically not router, but firewall with NAT.
<pedantic>Every NAT or firewall is technically some kind of router</pedantic>
More generally speaking,
I do not think any core network device blocks SCTP (nor anything else they do not recognize). So if two parties want to SCTP, they can by just reconfiguring their edge devices. Except for NATs, but NATs will disappear with the very near exhaustion of IPv4 addresses and the pressure of P2P applications.
You do not need the whole planet to be able to use a new protocol or service in order for it to get some traction. Zillions of people are forbidden to use facebook (and others...) at work. Does that dooms facebook?
Posted Nov 25, 2009 15:36 UTC (Wed) by foom (subscriber, #14868)
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> Except for NATs, but NATs will disappear with the very near exhaustion of IPv4 addresses
> and the pressure of P2P applications.
No they won't. Did you see the PR disaster Apple had when the Airport Express supported IPv6
without NAT? Everyone suddenly went "OMG my internal network is all exposed to the internet now,
giant security hole!!!". And of course, they were right -- that is unexpected behavior in today's
world. So, no doubt about it, NAT will live on even with IPv6. (When I say NAT there, I really mean
connection-tracking-based filtering: tacking the address translation on is trivial to do or not, but
it's the connection-tracking which would cause problems with SCTP).
But supporting SCTP has to start somewhere ? Why?
Posted Nov 25, 2009 18:57 UTC (Wed) by smurf (subscriber, #17840)
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>> When I say NAT there, I really mean connection-tracking-based filtering
So why do you call it NAT, if no address is actually translated?
But supporting SCTP has to start somewhere ? Why?
Posted Nov 25, 2009 23:55 UTC (Wed) by foom (subscriber, #14868)
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Because when people say "XXX is broken because of NAT", they actually mean "XXX is broken
because of stateful connection tracking and filtering".
They just say "NAT" because stateful connection tracking and filtering is an integral part of NAT, and
NAT is the most use. Of course it's possible to do a the connection-tracking without the address
rewriting, but the important thing to note it is not any less complex, and causes no fewer problems.
It still prevents you from having an end-to-end internet.
You still want to have protocol-specific parsing in order to find "related" connections which should
be allowed through. (e.g. with FTP). You'd still need a protocol like uPNP or NAT-PMP in order to
advise the firewall to open a hole for things like BitTorrent. There's almost no advantage at that
point versus actually having a NAT.
But supporting SCTP has to start somewhere ? Why?
Posted Nov 26, 2009 7:57 UTC (Thu) by smurf (subscriber, #17840)
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>> There's almost no advantage at that point versus actually having a NAT.
Sure there is.
You avoid starving the router of TCP (or SCTP) ports. You avoid having to mangle TCP packets because they happen to contain addresses. You avoid IP address based "one-connection-per-client" limits on servers.
In short, you can use simpler servers and routers. Which translates to fewer bugs and less power-hungry CPUs.
But supporting SCTP has to start somewhere ? Why?
Posted Nov 25, 2009 23:45 UTC (Wed) by marcH (subscriber, #57642)
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You are talking about default settings. I am talking about what is to become possible. Both are interesting, but quite different.
But supporting SCTP has to start somewhere ? Why?
Posted Nov 26, 2009 10:04 UTC (Thu) by marcH (subscriber, #57642)
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> Except for NATs, but NATs will disappear...
Sorry, I actually meant:
So if two parties want to SCTP, they can by just reconfiguring their edge devices. Except when they have only one old public IPv4 address to share. But quite soon many people will have ZERO IPv4 address to share, which will ironically solve the only major deployment problem of SCTP.