Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!mcsun!ariadne!nicolas
From: nicolas@csi.forth.gr (Nicolas Chrissakis)
Newsgroups: comp.dcom.lans
Subject: Re: FDDI question: bridges, routers, interoperability ...
Keywords: FDDI, bridges, routers
Message-ID: <1793@ariadne.csi.forth.GR>
Date: 24 May 91 19:04:14 GMT
References: <1779@ariadne.csi.forth.GR> <22755@shlump.lkg.dec.com>
Sender: news@csi.forth.GR
Distribution: comp
Lines: 52

koning@koning.enet.dec.com (Paul Koning) writes:


>|>Dear FDDI experts,
>|>
>|>We are planning to install 2 FDDI rings  and we are looking for comments
>|>or experiences from users.
>|>
>|>Here are some questions:
>|>
>|>I have a host A connected to an ethernet segment. The ethernet segment is
>|>connected on an FDDI bridge and the bridge on an FDDI ring. I have a
>|>host B connected to an ethernet segment. The ethernet segment is connected
>|>on a FDDI ethernet router and the router on the ring.
>|>
>|>My question is: Will A talk to B?
>|>
>|>The bridge will be Dec compatible translation bridge.

>Yes.  At the datalink level, A talks to the router's FDDI port; the
>router in turn forwards over its Ethernet port to B.  Since you said
>that the bridge is a translating bridge, it will turn A's Ethernet packet
>into the corresponding FDDI packet, which the router will understand.

>This ONLY works with translating bridges -- not encapsulating bridges.

Dear Paul,

Bridge vendors tell me that this works but router vendors tell me no it
does not. The router acts like a router and there is no transilation
function turned on. Have you SEEN this working. Where? So I contact them
and find out my self because vendors answers confuse me more than enlighten me.

Some router vendors say that only if the router has the ability to
act as a translation bridge otherwise no. Some say if the protocol is TCP/IP
then it will work for other protocols no.

All bridge vendors say yes but most have not tested it.

Anyone out there has installed FDDI bridges and FDDI routers (acting as 
routers only) and made them inoperate?


>|>...
>|>If routers are as fast as bridges why will some one use bridges?

Are routers as fast as bridges? Any real experiences?

Regards

Nicolas Chrissakis
Crete, Greece