a yet another stupid network topology

Yoon Jae Ho yoon at bh.kyungpook.ac.kr
Mon Oct 30 15:32:29 PST 2000

```I think that if you want to use small port Switches, how about consider the "Loki"

http://loki-www.lanl.gov/loki-image.jpg

which explain in the  http://loki-www.lanl.gov/loki-inside.html

or,

how about creating the FNN Designs

http://aggregate.org/FNN/

for the small beowulf (lesser than 5 nodes) ,

Instead using the solution before (4 NICs/node, projection from above, S: switch, N:
node; single elementary cell shown)

|   |
-N   N-
\ /
S
/ \
-N   N-

how about using  below solution 4 port Nic/node with no switch for economic reason.

|
-N   N-
\ /
/ \
-N   N-

--------------------------------------------------------------------------------------------------------
Yoon Jae Ho
Economist.
Seoul, Korea
3457-8228

yoon at bh.kyungpook.ac.kr

Imagination is more important than knowledge.  A. Einstein
--------------------------------------------------------------------------------------------------------

----- Original Message -----
From: Eugene Leitl <eugene.leitl at lrz.uni-muenchen.de>
To: <beowulf at beowulf.org>
Cc: <eugene.leitl at lrz.uni-muenchen.de>
Sent: Monday, October 30, 2000 10:58 PM
Subject: a yet another stupid network topology

>
> I've been thinking about network topologies for physical simulations
> (spatially distributed over nodes, only locally coupled). The
> assumption is that few-port FastEthernet switches are much less
> expensive per port and typically have a larger backbone bandwidth then
> larger switches. Is this still correct?
>
> The solution before (4 NICs/node, projection from above, S: switch, N:
> node; single elementary cell shown):
>
>   |   |
>  -N   N-
>    \ /
>     S
>    / \
>  -N   N-
>   |   |
>
> This one is scalable, but it is rarely possible (due to simple budget
> reasons) to go beyond 64 nodes, or so. Hence: the next stupid idea: we
> have only 64 nodes, 3 NICs/node and 12 16-port
> switches. (alternatively, same number of nodes, 4 NICs/node and 16
> 16-port switches). View the nodes as arranged on a 4x4x4 cubic
> lattice. Think the switches arranged thusly (projection from above):
>
> N N N N
>    S
> N N N N
>  S   S
> N N N N
>    S
> N N N N
>
> We use each 16-port switch to crosslink the individual 2x2x2 cubes
> along the larger cube axis. (In the larger 16 switch solution,
> switches also crosslink the 2x2x2 cubes along the larger cube axis).
>
> For all this to make sense, we need
>
> 1) 16-port switches are much cheaper/port than 32-port switches and
>    larger
>
> 2) above cheap 16-port switches can provide full 200 MBps*16 backbone
>    bandwidth
>
> 3) we can feed 3 (or even 4) FastEthernet NICs in a node
>
> If each of the switches have 1 GBps uplink port, we obviously can
> connect the whole system to a user pool without apparent bottleneks.
>
> I would welcome any comments on this scheme. (yea, nay, wtf, etc.).
>
> TIA,
>
> -- Eugene Leitl
>
> _______________________________________________
> Beowulf mailing list
> Beowulf at beowulf.org
> http://www.beowulf.org/mailman/listinfo/beowulf

```