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From: dcrocker@nsl.dec.com (Dave Crocker)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: UDP bind question
Message-ID: <9002151527.AA03143@dcrocker.pa.dec.com>
Date: 15 Feb 90 15:27:36 GMT
References: <9002150303.AA01899@yuba.WRS.COM>
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Well, there certainly is a difference between TPI and TLI, and I did
miss your reference in the original note, but I'm afraid that I don't
think it helps the issue much.

TPI is the in-kernel interface.  TLI is the application level mapping
to TPI, as you describe.

Unfortunately, the mapping between TPI and TCP (or UDP) is NOT
subject to inherent or even universal definition.  Basically, the
TLI and TPI interfaces assumed a TP4 environment.  (Yes, I know that
they claim to be protocol independent.  So did sockets.)  But there
still are places where a TCP implementor has choices of how to
make some of the functionality available.  The acid test is to
see the continued need for IOCTL within common applications.

Dave
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