OSI does not mean X.25


LYMAN_CHAPIN@ICE9.CEO.DG.COM
Thu, 31 Mar 88 10:00:58 EST


This just in from Juha Heinanen in Finland:

>> In article <>> In article <8803261505.AA04812@wb6rqn.UUCP> >> In article <8803261505.AA04812@wb6rqn.UUCP> brian@wb6rqn.UUCP (Brian Lloyd)
>> writes:
>> >European attendees. The consensus was that OSI really wasn't happening
>> >and that they were all planning to go the TCP/IP route. I guess that
>> >the ISO/OSI hard-sell has created a market that only TCP can currently
>> >fill.
>>
>> Pretty much a correct observation. The POLITICAL plan is to go the
>> connection oriented (X.25) OSI route that doesn't care about local
>> area networks (it only cares about the profits of PTT monopolies). So
>> if you want to build a LAN and connect it to another LAN what else
>> have you got except TCP/IP?

Evidently there are still people who see "OSI" and hear "X.25" and
"connections". ** THIS IS NOT A VALID ASSUMPTION! **

You can have OSI with a Transport protocol similar to TCP (ISO 8073)
and a connectionless internetwork protocol (ISO 8473) even more similar
to IP. You do not have to have X.25. You do not have to have PTTs.
You do not have to have network connections. There is NO part of OSI
that requires X.25 (although if X.25 is all you have, you can use it to
support OSI). OSI loves LANs. The OSI IP likes nothing better than
to connect LANs together (or to any other type of subnetwork).

With the ISO IP, you also get a host-gateway routing protocol (ISO
9542), and you will soon get a gateway-to-gateway routing protocol
(a link state routing scheme based on DECnet Phase V routing). If
you need X.25 to get across a PTT (or for any other reason), you
can run ISO IP on top of it (it looks like just another point-to-
point link), keeping the connectionless internet intact.

ALL OF THIS IS AVAILABLE *NOW*. The Transport, Internet, and host-
gateway protocol standards are done. They are not "working drafts".
They are being implemented. They are already available in commercial
products from at least one large computer manufacturer (DG). You
can get copies of the standards from your local national standards
body. In Finland, call Esko Ojanpera at (+358)-0-456 65-6.

-----------------------------------------------------------------------------
Lyman Chapin lyman@ice9.ceo.dg.com
Data General Corp. [lyman%ice9.ceo.dg.com@relay.cs.net]
(617) 870-6056
-----------------------------------------------------------------------------



This archive was generated by hypermail 2.0b3 on Thu Mar 09 2000 - 14:41:32 GMT