🚀 go-pugleaf

>Just what is meant by ... "ISO Transport Class 4 Protocol"

The classes refer to reliability of transport service provided by the
transport provider  which implements the transport layer. Gulp.

They range from class 1 which is "no error detection, no flow control"
to class 5 "flow control, error detection with error correction".
Class 2 is essentially what you would use for a datagram service,
while you would use 4 or 5 for virtual circuit service.

If you're really interested in the ISO OSI-RM you should check out 
one of the back issues of the IEEE magazine  --  one of them was a special
issue devoted to it.  (I think we are talking of the Transactions of IEEE)

Finally,  the calsses may be numbered 0-4 and not 1-5 (I forget).

-- 
			Marcus Hand	(mtunh!mgh)