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From: lizhen@silver.ucs.indiana.edu (Zhen Li)
Newsgroups: comp.protocols.iso
Subject: question about transport layer protocol
Message-ID: <1991Jan18.220611.14357@bronze.ucs.indiana.edu>
Date: 18 Jan 91 22:06:11 GMT
Sender: daemon@bronze.ucs.indiana.edu (Mr Background)
Organization: Indiana University
Lines: 33

Hello,

     In Marshall's Open Book when discussing transport 
protocol classes three network classes (Class A, B, and C)
are defined. 

 Quote:

     Class A:  networks that detect, as an error, any loss 
	       of data.  These networks never duplicate, 
	       re-order, or corrupt data. Furthermore, a 
	       class A  network has a relatively small 
	       probaility of actually losing data. Such a
	       network provides the CONS.

     Class B:  like class A networks, class B networks detect, 
	       as an error, any loss of data. However, such losses 
	       are more common that the transport service would 
	       prefer. Class B networks aren't necessarily unreliable,
               it's just that they are less reliable than class A
	       networks.  The distinction between the two classes is 
	       decided locally. Class B provide CONS.

     End quote.

     Could anybody give me a real example of class A network and class
     B network?

   Thanks in advance!

   Zhen  Li