[comp.dcom.lans] Cable Taps/No Cable Taps.

hollandm@prlhp1.prl.philips.co.uk (Martin Holland) (01/31/90)

This may be a naive question but is it permissable to connect one ethernet
AUI cable from an ethernet device into another instead of connecting each
to a cable tap and have these tapped into an ethernet cable.
I want to plug a bridge into a repeater. I know that an ethernet device
provides power for a cable tap so I suppose there could be some confusion
if two devices were supplying power to each other.  If this is not permissable
is there any other way around this as it seems that you have to have a lot of
redundant equipment to achieve this connection when the two devices are
sitting next to each other.

henry@utzoo.uucp (Henry Spencer) (02/07/90)

In article <1043@prlhp1.prl.philips.co.uk> hollandm@prlhp1.prl.philips.co.uk (Martin Holland) writes:
>This may be a naive question but is it permissable to connect one ethernet
>AUI cable from an ethernet device into another instead of connecting each
>to a cable tap and have these tapped into an ethernet cable.

Unfortunately, no.  The signals on the AUI cable are not symmetrical; you
need electronics in between.  Usually the cheapest way to do this is to
use a multi-port transceiver/AUI, as most of them can be configured so
that they don't need to actually connect to an Ethernet cable.
-- 
SVR4:  every feature you ever |     Henry Spencer at U of Toronto Zoology
wanted, and plenty you didn't.| uunet!attcan!utzoo!henry henry@zoo.toronto.edu

dd@ariel.unm.edu (dd) (02/13/90)

Martin Holland writes:

>This may be a naive question but is it permissable to connect one ethernet
>AUI cable from an ethernet device into another instead of connecting each
>to a cable tap and have these tapped into an ethernet cable.
>I want to plug a bridge into a repeater. I know that an ethernet device
>provides power for a cable tap so I suppose there could be some confusion
>if two devices were supplying power to each other.  If this is not permissable
>is there any other way around this as it seems that you have to have a lot of
>redundant equipment to achieve this connection when the two devices are
>sitting next to each other.

Standard disclaimer:  I am not affiliated with but am a satisfied
(small) customer of the ANC division of Netcor.

Try the ANC-10 AUI-to-AUI adapter.  Takes power from one side, has
nice diagnostic LEDs.

Can't just make a "null-transceiver cable", because of collision
detection logic.  An ethernet subscriber has to be able to hear
itself, approximately speaking.


-- 
Don Doerner				dd@ariel.unm.edu
University of New Mexico CIRT
2701 Campus Blvd, NE
Albuquerque, NM, 87131			(505) 277-8036

gjack@datlog.co.uk ( Graham Jack ) (02/16/90)

dd@ariel.unm.edu (dd) writes:

>Martin Holland writes:

>>This may be a naive question but is it permissable to connect one ethernet
>>AUI cable from an ethernet device into another instead of connecting each
>>to a cable tap and have these tapped into an ethernet cable.
>>I want to plug a bridge into a repeater. ......