Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!cs.utexas.edu!uunet!tci!darcy
From: darcy@tci.UUCP (Jeff d'Arcy)
Newsgroups: comp.dcom.lans
Subject: Re: BRIDGE's (ROUTER's) (GATEWAY's)
Message-ID: <335@tci.UUCP>
Date: 5 Aug 89 16:00:56 GMT
References: <11146@ibmpcug.UUCP>
Organization: Technology Concepts, Inc. Sudbury Mass.
Lines: 26

bobkil@ibmpcug.UUCP (Bob Kilgore) writes:
>The discussion has raised an interesting point that I have
>been considering for some time.  What exactly is a 'BRIDGE',
>a 'ROUTER', and a 'GATEWAY'.  It seems to me that there were

My understanding:

A bridge is a link level device that joins two separate media of similar *or*
different types to provide the appearance of a single uninterrupted medium.
Thus, there may be Ethernet bridges, Ethernet-Token Ring bridges, etc.

A router is an network level device that provides communication between nodes
that are not directly connected but use the same network-level protocol (IP,
DECnet, etc).

Gateways are not, in my experience, as clearly defined as the other two items.
IMHO, "gateway" refers to a session or higher level device that performs
translations between different protocols of the same basic service type (such
as AppleShare to NFS or SMTP to VMSmail).  Others use the term to refer to
network or transport layer devices that perform different-protocol same-service
translations (IP-DECnet would be an example if such a beast existed).

Don't bother correcting me; this is just my opinion/understanding of the
-- 
Jeff d'Arcy		...!uunet!tci!darcy		(508) 443-7311 x283
	TCI is not responsible for my opinions, nor I for theirs