- From: Mark Baker <distobj@acm.org>
- Date: Mon, 9 Sep 2002 11:20:20 -0400
- To: Elliotte Rusty Harold <elharo@metalab.unc.edu>
- Cc: www-tag@w3.org
Elliotte, On Mon, Sep 09, 2002 at 10:05:17AM -0400, Elliotte Rusty Harold wrote: > SEction 1 of the arch draft states: > > Protocols. A small and nonexclusive set of protocol specifications > for interchanging information between agents, including HTTP > [RFC2616], SMTP, and others. Several of these protocols share a > reliance on the Internet Media Type (or, "MIME") the > metadata/packaging system [RFC2046]. Just to be clear, because I think the draft is, SMTP is said to be included as part of the Web, not of Web architecture per se. > I am not sure SMTP properly belongs here for a number of reasons: > > 1. SMTP significantly predates the rest of what we call the Web. As do a lot of other protocols. But, while not being privy to the TAG discussions that concluded that it be mentioned, I think the key point here is that Web architecture *subsumes* a substantial part of many other systems. Specifically, for SMTP, SMTP end point identifiers (email addresses), have been subsumed via URI-izing. In addition, the SMTP "DATA" method can, to a meaningful (though incomplete) extent, be subsumed by HTTP POST. By "incomplete" I mean that some SMTP features would be lost in this subsumption, but it could still be done, and email messages could be sent. IMO, a litmus test about whether another system could be counted as part of the Web would be; a) are the operations of this system performed on things with identity (i.e. can they be URI-ized)? b) could an HTTP gateway be constructed which mapped the application interface of this system to HTTP's application interface (perhaps extended), while preserving enough of the other system's functionality to be useful? In my definition, a) is necessary and sufficient for a system to be counted as part of the Web. This would include SMTP, FTP file transfer, telnet sessions, etc.. However, of those, I believe that only SMTP and FTP could be usefully interacted with via HTTP's interface. Telnet, by virtue of its stateful, fine-grained messages, could not usefully be wrapped. So there's certainly degrees of "being part of the Web". > Note that the same arguments apply to NNTP and Usenet news. FTP and > gopher, by contrast, though not traditionally W3C protocols, are at > least similar enough in structure to HTTP to justify being included. > HTTPS obviously can be included. NNTP is another example of a system that would probably pass both a) and b) above. GET to retrieve news articles, POST to send them (indeed, IIRC, the HTTP method name "POST" was taken from NNTP), URIs to identify the server/group and individual articles. However, the current deployed subsumption of Usenet only meets the criteria in a) (i.e. you can click on news:alt.foo.foo and your newsreader pops up). MB -- Mark Baker, CTO, Idokorro Mobile (formerly Planetfred) Ottawa, Ontario, CANADA. distobj@acm.org http://www.markbaker.ca http://www.idokorro.com
Received on Monday, 9 September 2002 11:20:56 UTC