[comp.dcom.lans] Token Ring installation

rainer@hwsw.gedas.de (Rainer Raupach) (03/01/91)

Hi Netlanders,

we are doing a project with LMX on Token Ring. I would like
to know, if there`s any installation with some 30 Token Rings
connected via bridges.
Does somebody know of one installation this big or even bigger?

Pls email.

Thx Rainer
-- 
---
Rainer Raupach		Internet: rainer@hwsw.gedas.de
Network Coordinator	X.400:	too long to display here
VW-GEDAS Berlin, GER 	Phone:	+49 30 39007-629  / FAX : ext -999

haas%basset.utah.edu@cs.utah.edu (Walt Haas) (03/02/91)

In article <787@hwsw.gedas.de> rainer@hwsw.gedas.de (Rainer Raupach) writes:
>Hi Netlanders,
>
>we are doing a project with LMX on Token Ring. I would like
>to know, if there`s any installation with some 30 Token Rings
>connected via bridges.

I'm under the impression that attempting source routing with that many
rings would exceed the size of the source routing field in the packet
header.

I'm sure somebody on the net will correct me if I'm wrong :^)

-- Walt Haas    haas@ski.utah.edu

franka@hpctdlb.HP.COM (Frank Actis) (03/05/91)

> > we are doing a project with LMX on Token Ring. I would like
> > to know, if there`s any installation with some 30 Token Rings
> > connected via bridges.
> 
> I'm under the impression that attempting source routing with that many
> rings would exceed the size of the source routing field in the packet
> header.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

It depends on how you interconnect the LANs.  If you use a single
backbone ring, any node is only two bridges from any other system on 
the LAN.

	  Backbone Ring	 
 		 _			A
		| |			|
		| |-Bridge ----------------------
 		| |-Bridge ----------------------
		| | .
		| | .
		| | .
		| | .
		| | .
		| |-Bridge ---------------------
		|_|-Bridge ---------------------
					|
					B

As you can see, there are only two bridges between nodes A and B.

If you were to connect many LANs in a serial fashion, you would quickly
exceed the maximum number of hops that source routing can handle for 
any particular path (7).

Frank Actis
Hewlett-Packard
Colorado Telecommunications Division
franka@hpctdlb.col.hp.com