Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!purdue!decwrl!ucbvax!A.ISI.EDU!PADLIPSKY From: PADLIPSKY@A.ISI.EDU (Michael Padlipsky) Newsgroups: comp.protocols.tcp-ip Subject: Re: Does TCP/IP "comform" to ISO/OSI? Message-ID: <12426875226.25.PADLIPSKY@A.ISI.EDU> Date: 31 Aug 88 18:24:24 GMT References: <24642@bu-cs.BU.EDU> Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 26 Kent England: Just for the record, it seems to ME that there's no connection whatsoever between my observation that TCP/UDP-IP is philosophically closer to the "Reference Model" than X.25-X.75 and "this argument of 'OSI implies X.25 and X.75'" you mention. If anything, the observation is more reasonably misconstruable as a suggestion that OSI precludes X.25-X.75 than that it implies 'em, although it doesn't say that either. Of more interest, however, is whether you'll actually be able to satisfy your stated expectation that you won't "have to run OSI protocols over virtual circuit networks " "[i]n the US": As long as DDN and GOSIP mandate X.25, neither ARPA nor ISO IP users will be able to avoid paying (in one or more senses) for unasked-for subnet functionality, in the long haul, as it were. Are you, perhaps, counting on ISDN to save the day? (For that matter, does anybody out there know for sure whether ISDN, unlike X.25, WILL offer datagram service, and, unlike X.75, dynamic/"real" alternate routing?) If so, you'd be better advised to argue with the proprietors of DDN and the propounders of GOSIP about the non-OSIness of X.25, not with me, since the bold-face line in the middle of p.154 of _The Elements of Networking Style_ (Prentice-Hall, 1985) proves that I haven't lumped OSI and X.25 for several years--even if I'll never forgive the panacea pedlars who had tricked me into lumping them previously. cheers, map -------