Token ring hub

Glen Heiberg Glen.Heiberg at gijima.com
Mon Jan 15 01:31:07 CST 2007


You could look out for an original IBM 8228 MAU (Multistation Access
Unit). These have 8 workstation ports and a pair of RI/RO (Ring In-Ring
Out) ports, and is a passive device (did not need AC power).
Alternatively, you could look out for an IBM 8230 CAU and LAM (or the
Madge equivalent). However, these are quite bulky. All the above use the
big IBM connectors with type-1 cabling. Cat 5 cables with RJ45
connectors can be used as long as you use a balun.

I have never encountered a tokenring NIC that only had RJ45 connectors;
there was always a DB9 connector. Also, you don't need any "token ring
starter upper". The first station that inserts into the ring generates
the token. All stations must use the same ring speed (either 4Mbps or
16Mbps). The first station that joins the ring must be set to a fixed
speed; subsequent stations inserting into the ring can be set to
autosense the ring speed.

If the EISA TR NIC you have is indeed a 100Mbps device, it will only do
100Mbps TR when connected to a 100Mbps TR switch, and these seem to be
fairly rare.

For moderate to high network loads, a 4Mbps TR network would run rings
;-) around an equivalent 10Mbps Ethernet network.

For simple TCP/IP connectivity between a TR and ethernet network, setup
a Linux box with any IBM TR nic based on the "tropic" chipset or a Madge
NIC (Linux drivers availble from their website) and your choice of
supported ethernet NIC, and setup IP routing.

Regards
Glen,


Teo Zenios wrote:
>
>Also what is a good way to bridge Token Ring to Ethernet so that these
486 machines can use my router/cable modem?
>  
>
Jim wrote:
>I purchased some 3Com 3c359's off ebay, and built up a linux box to
>bridge them.
>
>There is a 3c509 on the ethernet side.  There is a 3174 on the token
>ring.  It is a standard MAU, no rj45 baluns.  Don't forget on ancient
>MAU's you have to have a token ring starter upper, to charge up
>the hub.  I had a years old one, and was informed to use the supplied
>IBM starter to set up mine.  I might point out that the MAU had no
>active power, as some of the ones which use rj45's do, and that
>may have had to do with the "starter upper" gizmo.
>
>Anyone who can educate me on that one would do me a favor, I
>just did it and it worked (after replacing the 9v battery in the IBM
>gizmo)
>
>Jim




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