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From: hrs1@cbnewsi.att.com (Herman R Silbiger)
Newsgroups: comp.dcom.telecom
Subject: Re: Prodigy Communications Protocol
Message-ID: <15344@accuvax.nwu.edu>
Date: 7 Dec 90 13:12:41 GMT
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In article <15214@accuvax.nwu.edu>, snowgoose!dave@uunet.uu.net
writes:

> The user's manual asserts that NAPLPS, North American Presentation
> Level Protocol Standard, is the communications protocol.

> But, it seems the tech support people at PRODIGY don't know this.
> They assert, wrongly, that the downstream communications is compressed
> bit-maps.

NAPLPS is the North American Presentation Layer Protocol Syntax.  It
is not a protocol, but a syntax for the image coding.  NAPLPS is
resolution independent, and controls a variety of methods to actually
produce the image.  There are two other standardized videotex coding
syntaxes, the European CEPT, and the Japanese CAPTAIN.  All are
standardized in CCITT Rec. T.101.  A method for Videotex systems to
interwork has been standardized and uses ODA (Open Document
Architecture) as an interchange method.  ODA uses ASN.1 (Abstract
Syntax Notation One) as a syntax.

I have no idea what the actual communications protocol is that Prodigy
uses to communicate with the PC.


Herman Silbiger
hsilbiger@attmail.com