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From: eshop@saturn.ucsc.edu (Jim Warner)
Newsgroups: comp.dcom.lans
Subject: Re: anyone out there with American Photonics RL-5000's?
Message-ID: <1291@saturn.ucsc.edu>
Date: Mon, 30-Nov-87 22:11:50 EST
Article-I.D.: saturn.1291
Posted: Mon Nov 30 22:11:50 1987
Date-Received: Fri, 4-Dec-87 05:06:43 EST
References: <209@yetti.UUCP> <19386@amdcad.AMD.COM>
Reply-To: eshop@saturn.ucsc.edu (Jim Warner)
Organization: University of California, Santa Cruz; CIS/CE
Lines: 23
Keywords: API, fiber optics, 802.3, transceiver cable, RL-5000

In article <19386@amdcad.AMD.COM> phil@amdcad.UUCP (Phil Ngai) writes:
>In article <209@yetti.UUCP> eriks@yetti.UUCP (Eriks Rugelis) writes:
>>They call it a 'Fiber Optic Ethernet Expander'.  
>
>.... First of all, the
>heartbeat gets delayed.  Second, your data echo gets delayed. Though
>many pieces of equipment may work, who's to say someone won't design a
>piece of equipment which knows that transceiver cables are never
>longer than 50 meters? 

The problem of delayed data is occurs with broadband transceivers
(Chipcom) and other fiber optic transceivers (Codenol) as well.
In a broadband system, the signals must travel all the way to the
head end before they are returned to the receiver section.  There
is definitely lots of equipment that will not tolerate this delay.
These transceivers provide local (faked) echo.  The Codenol rep
told me there is a jumper internal to the transceiver to disable
local echo, but there is never any reason to change it.

I would be real suprised if the "Ethernet Expander" didn't do the
same, but it is definitely a good question to ask.

jim warner                                     eshop@saturn.ucsc.edu