Subject: Re: How to network
To: None <port-vax@NetBSD.ORG>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: port-vax
Date: 08/23/1997 18:30:10
>>	There are three ethernet cable types:
>>	[10base5]
> I've always heard of 10Base-5 cable as being "AUI cable"?

Probably because nobody has ever done 10base5 with anything but an AUI
interface on the host.  Strictly, "AUI cable" ought to refer to the
cable between the female DB15 on the host and the male DB15 on the
transceiver, the thing that's usually spoken of as a "drop cable";
that's the only cable that's really associated with the AUI interface.

>>	[10base2]
> And if you have problems with slightly bad 10Base-2 cable(s) then
> it's *very* difficult to find the bad cable.  Plus, DELNIs are cheap
> (a DEC 10Base-5 hub of sorts)

More accurately, an AUI multiport transceiver.  Not related to 10base5
except in a simultaneous-chronology sense.  (Unless I misunderstand
what a DELNI is - I'm assuming it's a box with a bunch of AUI
transceiver interfaces and one AUI host interface.)  Indeed, I have an
AUI multiport box at home and the "real" medium is 10base2, not
10base5; the box doesn't know the difference - all it knows is, its
station port is connected to something implementing the AUI transceiver

> so I'm switching over to 10Base-5 as I can.

You really don't want to do 10base5, trust me. :-)  The cable is
unwieldy, ugly, and very sensitive to physical disturbance.  Since
nobody does 10base5 with anything but AUI interfaces (and therefore any
machine you have on 10base5 must have an AUI interface), I'd say you'd
be better off using a 10base2 or 10baseT transceiver with thinnet or a
twisted-pair hub.

Of course, if you really mean you're going AUI, then that sounds
relatively reasonable.  The biggest problem you'll face is machines
that have BNC and/or twisted pair, but no AUI.

>>	[10baseT snipped]

>>	Plus three types of ethernet interface:
>>	AUI:  Female 'D' type connector.  [...]  Requires an external
>>	      transciever to connect to any of 10base5, 10base2, or
>>	      10baseT.
> Really requires a transciever to connect to 10Base-5?

Yes.  A host AUI interface cannot be (usefully) connected to anything
but a tranceiver's AUI interface.  (10base5 refers to thicknet, not
AUI, though they're often confused because (a) 10base5 is the only
technology that never pushes the tranceiver into the host (hosts often
have BNC connectors for 10base2 or RJ45-ish connectors for 10baseT, but
there is nothing analogous for 10base5) and (b) probably for related
reasons, AUI fell out of favor about the time 10base5 did.)

					der Mouse

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