question about Bonding tools

Bill Northrup nodezero at pacbell.net
Mon Oct 23 01:20:36 EDT 2000


Chris and Florent,

Well I am not to familiar with your switch, but it appears to be the
problem. Before we go into depth on switching technology's, I would like to
ask you a little about the application that we are talking about. I am very
new to Beowulfs so I will operate under a few assumptions. The 3500 series
(the 3548 XL caught my eye) seems to be a nice choice.

1)That  you have identified that network bandwidth is the current bottleneck
in the system?  I believe that bonding adds a little overhead to the node as
well cost and  latency. Is the amount of anticipated speed up for you
application worth the additional cost?

2) how many nodes?

3) How does latency effect your application? Is it large amounts of data
with long computer times or is small and bursty with time sensitivity to
overall system performance? If it was the large data model with higher
tolerance for latency I would select either a store and forward type switch
or cut through. For the time sensitive I would chose the cut through. To be
honest I am grasping at this one, because I do not know how these numbers
affect the Beowulf. Store and forward= buffer the entire frame and check CRC
before forwarding out the destination port. Cut through = begin forwarding
it out the destination port before the end of the frame, no crc check..

4) Future plans and scalability? It's nice to keep all nodes on the same
chassis..

5)Pricing constraints? Cisco is expensive and you may pay for some very fine
features you will never use!! But I love Cisco!! The ability to span a port
or copy all traffic to another port so you analyze it with a sniffer is very
nice. Other manufactures have this function as well, but your cheaper ones
do not...

6)Gigabit uplink needed or Gigabit connection with master node(s)?

I have many consultant tools and connections available to me, I would be
more than happy to help you narrow down some switches with just a little
more info. Please feel free to volunteer any information that I might need
to know.

By helping you I am helping myself.

Bill












----- Original Message -----
From: "liuxg" <beowulf at eyou.com>
To: "Bill Northrup" <nodezero at pacbell.net>
Cc: <beowulf at beowulf.org>
Sent: Saturday, October 21, 2000 6:52 PM
Subject: Re: question about Bonding tools


Hello,Bill Northrup ,Chris Greer and Florent Calvayrac ,
     May be the reason is my switch. Its model is
LS-3016, a 16 ports produced by Legend Inc.
     I have read all doc with the switch. It only support
VLAN and trunking,no fast etherchannel. May be I should buy
a new switch, which model do you  recommend? Cisco catalyst
3500 series?


in 00-10-22 3:47:00 writed£º
>Liuxg,
>
>
>No, trunking is the "backbone" or "master" connection back to the core of
>the network. (keeping the topology basic here).. The term 'trunking' is
>reserved for when you are encapsulating frames with VLAN tags back to core
>switch or router. As a side note, the encap methods are ISL (Cisco
>proprietary) and 802.1q (RFC style)... You would be looking for (hold on,
>beer going dry) (ok, I am back) would be 'etherchannel' or 'channelbonding'
>in the switch configs / documentation...  What type and model of switch are
>you running?
>
>Almost 4 am, I hope this makes sense :)
>
>Bill
>
            liuxg
            beowulf at eyou.com



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