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Re: [tcpm] TCP, multiple addresses and soft errors when connecting

At 09:25 05/04/2004 +0300, Pekka Savola wrote:

> >  2) state the desire for getting a better higher-level API which would
> >handle all of this and much more (instead of/in addition to 1), but
> >mention why this is not an only practical solution.
> What do you mean "this is not an only practical solution"?
What I should have said if "but mention why this is would not be a
practical solution, if there were no other solutions".

Actually, I think it is the only real solution to the problem.
Having the API report ICMP errors to the application is moving the problem from the API to the application, but *not* solving it.

If you leave connect() as is, then you may have the delay problem you describe (i.e., you may suffer undesirable delays to use a service).
If you make it report ICMP errors to the application, you still have a problem I mentioned in the other e-mails. You might even say that you'll have application programmers (probably *not* knowledgeable on TCP/IP internals) handling issues of the underlying protocols.

So a real solution is to hide all this stuff from the application programmer. Let him just concentrate on actually using a service, and handle all the protocol-related issues inside the API.

Furthermore, if for whatever reason you need to change the behavior of connect() in the future, then, unless you provide a more "abstract" connect(), you'll have to "bother" application programmers again.



That is, new APIs would be great, but we cannot stop fixing problems
current APIs until we have something more concrete out there.
Otherwise we'd end up with no practically (in short term) deployable
solution.

If you consider it useful, I could try to continue thinking on the "abstract" API. I'm just thinking about writting some stuff down, so that there's a place from which which can move things forward. It may take me some time (say, months), but...

(BTW, for those interested tcpm-only readers, I've just posted a message with subject "Some comments on draft-ietf-v6ops-v6onbydefault-01.txt" on the v6ops list, that's related to all this. I can forward it to to the tcpm list, if you want).


--
Fernando Gont
e-mail: fernando@gont.com.ar || fgont@acm.org