Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!rutgers!njin!princeton!siemens!demon!fwb
From: fwb@demon.siemens.com (Frederic W. Brehm)
Newsgroups: comp.misc
Subject: Re: A Comparison of Commerical RPC Protocols
Keywords: RPC Apollo Sun Netwise
Message-ID: <12159@siemens.siemens.com>
Date: 20 Jul 89 14:19:56 GMT
References: <6567@joshua.athertn.Atherton.COM> <951@anise.acc.com>
Sender: news@siemens.siemens.com
Reply-To: fwb@demon.UUCP (Frederic W. Brehm)
Organization: Siemens Research and Technology Laboratories
Lines: 17

In article <951@anise.acc.com> lars@salt.acc.com (Lars J Poulsen) writes:
>... OSI mandates an ASN.1
>presentation layer, while TCP/IP usually punts this by specifying a
>standard representation equal to the natural representation on either a
>VAX or an MC68K or soon to be iAPX386. This ensures that some group of
>users get an efficient implementation, while the ISO model guarantees
>equal and equally bad performance for all.

You forgot that the Session layer can negotiate the presentation encoding.
The basic encoding for ASN.1 is required for conformance, and therefore
interoperability.  Private encoding methods (like the TCP "punt") may be
used if both participants agree.  This ensures that some group of users get
an efficient implementation, while all users may communicate.

--
Frederic W. Brehm	Siemens Corporate Research	Princeton, NJ
fwb@demon.siemens.com	-or-	princeton!siemens!demon!fwb