Path: utzoo!attcan!uunet!lll-winken!rogue.llnl.gov!oberman
From: oberman@rogue.llnl.gov
Newsgroups: comp.dcom.lans
Subject: Re: Plugging repeater into DELNI: why not?
Message-ID: <1991Jan24.145614.1@rogue.llnl.gov>
Date: 24 Jan 91 21:56:14 GMT
References: <1991Jan22.123047.397@arizona.edu> <1991Jan22.224925.1818@nmt.edu> <1991Jan23.143949.400@arizona.edu>
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In article <1991Jan23.143949.400@arizona.edu>, leonard@arizona.edu (Aaron Leonard) writes:
> Let me, then, propose some rules for hooking up repeaters to 
> multiport transceivers, so that the more knowledgeable among you
> might shoot them down:
> 
>     1. A DEREP can be plugged only into an H4000-A (or any other
>     transceiver that offers heartbeat), but not into a non-SQE
>     transceiver, or a DELNI, 'cause DEREPs are old and weird.

N.B. While this is true, please be careful! The DEREP is an Ethernet V2 device,
not 802.3 complient. It must be hooked to an Ethernet V2 transceiver. N0 802.3
transceiver (Regardless of SQE) will work properly. Many folks confuse
heartbeat and SQE. They are similar but not quite the same. Heartbeat is
present on all Ethernet V2 transceivers. SQE is selectable on 802.3
transceivers. Since the H4000-A is about the only Ethernet V2 transceiver
available, the DEREP pretty much requires this device for it's connection.

> 
>     2. A DEREN can be plugged into any available transceiver but not
>     into DELNIs 'cause DELNIs are old and weird.

Well, at least weird. But not really old. I just bought one.
 
>     3. No third-party repeater can be plugged into a DELNI 'cause
>     DELNIs are etc.

Actually, you can if you adhere to heartbeat rules. I have done so with no
problem. Check the DEMPR manual and you will find that even DEC supports this.
 
>     4. Any third-party repeater can be plugged into any non-SQE (802.3)
>     transceiver or into any third-party multiport transceiver, as long
>     as the multiport transceiver does not transmit SQE. 
>     [This rule in particular I offer in order to draw flames.]

Hey, this is the only one I can't comment on. (Just because I don't know about
very many third party products.)
 
					R. Kevin Oberman
					Lawrence Livermore National Laboratory
					Internet: oberman@icdc.llnl.gov
   					(415) 422-6955

Disclaimer: Don't take this too seriously. I just like to improve my typing
and probably don't really know anything useful about anything.