Path: utzoo!attcan!uunet!mcvax!ukc!stl!stc!datlog!dlhpedg!cl From: cl@datlog.co.uk (Charles Lambert) Newsgroups: comp.edu Subject: Re: Online Journal of Distance Education Summary: Coloured Book protocols go beyond JANET communication. Message-ID: <825@dlhpedg.co.uk> Date: 14 Jul 88 18:02:32 GMT References: <5381@dasys1.UUCP> Sender: news@dlhpedg.co.uk Reply-To: cl@datlog.co.uk (Charles Lambert) Organization: FSD@Data Logic Ltd, Queens House, Greenhill Way, Harrow, London. Lines: 23 In article <5381@dasys1.UUCP> patth@dasys1.UUCP (Patt Haring) writes: > >By Andy Boddington, A_BODDINGTON@VAX.ACS.OPEN.AC.UK > >Coloured Book ProtocolA set of protocols governing mail, file and job > transfer between JANET sites. So named because each protocol is > in a book with a different coloured cover. Almost; but the Coloured Books do not originate from JANET. They describe the seven layer model of communication between computers proposed by the International Standards Organisation (ISO). The seven layers form a hierarchy of abstractions of the communication, from the shape of the cable plug to the facilities that the operating system offers the programmer. Each layer is described in one of the coloured books. When I last looked (which was several years ago) only the bottom four layers were clearly understood by the industry at large; the boundaries between the rest were the subject of personal interpretation and much hand-waving. Fortunately (or perhaps causally), the clearly understood layers are the ones involved in node-to-node and internetwork communication. ----------------- Charles Lambert