Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!pasteur!ucbvax!MOE.MCRCIM.MCGILL.EDU!philipp
From: philipp@MOE.MCRCIM.MCGILL.EDU (Philip Prindeville)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Does TCP/IP "comform" to ISO/OSI?
Message-ID: <8809021853.AA01665@Moe.McRCIM.McGill.EDU>
Date: 2 Sep 88 18:53:44 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 17

Mike (or anyone else),

	Care to set me straight on X.25 and its place in the ISORM?
I have always found this a dilema.  If you use the D-bit (end-to-end
delivery confirmation), it becomes a transport protocol (or tries to
be anyway).  But in other respects, it is deficient as a transport
protocol: for example, it provides no transport level addressing;
sessions must use the network level addressing and "hints" in the
call request user data field (sigh).

	As for its network (and data link) layer, it provides services
that should be going on at the transport layer, such as acknowledgement
and flow-control.  So aesthetically, how does it "stack up"?

Thanks,

-Philip