[DISC] Version ranges...

[Andrew Wilson <a.wilson@elsevier.co.uk>]

I'm not happy with the way version ranges are described.

http://www.research.att.com/~davek/mcp2.html 

'A note on version ranges' says:

    If there is any doubt about whether an intermediate version exists
    or is supported, an implementation should advertise a range
    including only those versions known to be supported.

Given good support for 1.0 and 2.0 but questionable support for 1.5
which 'range' should be publicised?

	#$#mcp min-version: 1.0 max-version: 1.0
or
	#$#mcp min-version: 2.0 max-version: 2.0

Assuming that an agent MUST only send '#$#mcp' once in the initiation
phase how can this single message be used to indicate the full range of
supported protocols to a peer?

As an agent I'd *like* to be able to send 2.0, because it's a nicer
version, but my peer may only speak 1.0 with confidence.  If I cover my
back and send 1.0 then the peer will never know that I could also speak
2.0 even if it could also speak 2.0

Ay.

-- 
Andrew.Wilson@cm.cs.ac.uk          http://www.cs.cf.ac.uk/User/Andrew.Wilson/