SUMMARY: Network sizing question

From: Gautam Das (gautam@bwc.org)
Date: Mon Dec 02 1996 - 13:11:26 CST


Thanks to
Alex Finkel <afinkel@pfn.com>
Robert Dexter <rdexter@xylan.com>
Roberto Gutierrez <rgut@nacion.co.cr>
and someone who wanted to remain anonymous.
They offered valuable advise.

Here's my original query followed by the responses.

>Hi!
>
>We are planning to move 500 desktops (currently only 150 of which are
>graphic capable i.e PCs/Xterminals) to Xterminals. They will be running
>Wincenter, unless by the time I get to implement this plan, Java terminals
>are available and Correl Office or its equivalent is running really well on
>Java. That will change our implentation plans.
>
>Anyway thats the background. I am looking at the following scenario --
>
>1. 500 desktops (400 NCD exploras + 100 PCs)
>
>2. 20 to 30 Wincenter Servers - PC application servers
>
>3. 25 100/10 Fast ethernet switches - dedicated 10MB to each desktop
> - May be a bit of overkill
> - How do 3com switches compare with Ciscos?
>
>4. 6-10 100/100 Fast ethernet switches - between servers.
>
>5. 30 Sun-Servers - both Application and Oracle database servers -
> - We have these already.
>
>6. Raid NFS/Samba Home directory servers - Solaris based preferred.
>
>Questions:
>
>I would like to hear opinions on the number of Raid boxes I will need and
>network sizing.
>
>1. How many raid servers do I need to serve a user community of 500? Also
>details of manufacturer and rough price estimates are welcome. Whats the
>maximum number of concurrent users supported on a RAID box, without
>sacrificing performance?
>
>2. Would like to use Solstice Backup. Any comments? Can NT be backed up
>using Solstice Backup?
>
>3. How do I split the network to sustain x number of users on a segment
>with Unix app servers, Raid NFS home-directory servers, Wincenter
>Multi-user NT servers, and Unix Oracle database servers? I am trying to
>get at the magic number of stations that I can have on a segment for
>optimum performance.
>
>4. What is the best upgrade plan for my existing Suns to 100-T ethernet?
>Suggestions for particular ethernet adapters are welcome.
>
>5. I am looking at a RMON based network analysis package called
>Armon to help size the network properly. Would love to hear from any one
>with experience with Armon ( from Bay Networks) or similar package.
>Alternate suggestions, including freeware are welcome.
>
>Needless to say I will post a summary.
>
>Thanks.

------------------------------------------------------
>From afinkel@pfn.com Wed Nov 20 23:13:12 1996
Date: Wed, 20 Nov 1996 10:36:34 -0500
From: Alex Finkel <afinkel@pfn.com>
To: Gautam Das <gautam@bwc.org>
Subject: Re: Network sizing question

At 04:20 PM 11/20/96 +0200, you wrote:
>1. How many raid servers do I need to serve a user community of 500? Also
>details of manufacturer and rough price estimates are welcome. Whats the
>maximum number of concurrent users supported on a RAID box, without
>sacrificing performance?

A Sparc Storage array with 6 2GB drives will run about $20k USD and can be
expanded to 30 2GB drives. Don't know about others off hand.

Concurrent users supported would be dependant on the kind of usage (email,
database, development).

>2. Would like to use Solstice Backup. Any comments? Can NT be backed up
>using Solstice Backup?

Yes. You need to buy the Client TurboPack for Desktop which provides the
software for NT/95/Win31/Mac but does not include additional client licenses.

>3. How do I split the network to sustain x number of users on a segment
>with Unix app servers, Raid NFS home-directory servers, Wincenter
>Multi-user NT servers, and Unix Oracle database servers? I am trying to
>get at the magic number of stations that I can have on a segment for
>optimum performance.

Make sure the servers have a bigger pipe than the clients. If you put the
clients on a 10MB Switch Port, put the servers on a 100 MB port.

You should consider switches with support for VLANs. That way you can
reconfigure your segments in software instead of swapping cables on
switches/hubs.

-------------------------------------------------------------------

Date: Wed, 20 Nov 1996 08:55:57 -0800
To: Gautam Das <gautam@bwc.org>
Subject: Re: Network sizing question

>
> 6. Raid NFS/Samba Home directory servers - Solaris based preferred.
>
We're looking at that issue right now, and I have been hearing
nothing but VERY GOOD things said about Network Appliance boxes.
I think it would be worth your while to look at their web page,
and possibly talk to a sales critter about some of the advantages
of their product. (Particularly in the backup arena...)

        http://www.netapp.com

The native multi-protocol file system (NFS, SMB) meshes pretty well
with our Unix/NT/WinCenter environment.

---

For a network of your size, you might consider ATM or FDDI switches instead of fast-ethernet. I haven't been in the backbone market lately, but in the past, the more robust solutions (if availability/throughput are a concern) were on ATM or FDDI.

I would be looking at 3COM Cellplex for ATM and DEC Gigaswitch for FDDI switching.

---

If you're going to include respondent's names in your summary, I would prefer to remain anonymous.

Good Luck - looks like an interesting project.

----------------------------------------------------------------

>From rdexter@xylan.com Wed Nov 20 23:15:33 1996 Date: Wed, 20 Nov 96 09:01:13 PST From: Robert Dexter <rdexter@xylan.com> To: gautam@bwc.org Subject: Re: Network sizing question

> Hi! > > We are planning to move 500 desktops (currently only 150 of which are > > ... > > 3. 25 100/10 Fast ethernet switches - dedicated 10MB to each desktop > - May be a bit of overkill > - How do 3com switches compare with Ciscos?

I may be somewhat biased, but take a look at Xylan's switches.

http://www.xylan.com

Good luck with whatever you choose.

Bob

--------------------------------------------------------- | Robert Dexter | Senior Test Engineer | | rdexter@xylan.com | Xylan Corporation | | rdexter@earthlink.net | 26679 Agoura Rd. Ste 100 | | (818) 880-3500 x3577 | Calabasas, CA 91302 | | (818) 880-3560 FAX | | --------------------------------------------------------- --------------------------------------------------------------

>From rgut@nacion.co.cr Fri Nov 22 08:45:32 1996 Date: Thu, 21 Nov 1996 10:23:58 -0600 From: Roberto Gutierrez <rgut@nacion.co.cr> To: Gautam Das <gautam@bwc.org> Subject: Re: Network sizing question

I just come from a Networkers Cisco Seminar for Latin America, last week. Network experts (no marketing) said I do not have to worry about broadcast in a switched environment when I have less than 200 nodes. So you need to worry about broadcast, that means maybe needing some sort of VLAN between your routers and switches, so when comparing 3COM switches with Ciscosīs, this is an issue. Cisco just brought out (not tried) a nice box, 24 10BT ports, 1 Aui, 2 100BT port, very good specs performace, etc.. in the box, called Catalyst 1900, or the Catalyst 2820 with uplink coices, Cat 1900 runs for $3,995,00

But essentially you may end up needing both a router(s) and switches. Your overall topology is really important, and do not discard any alternative, say many small switches, vrs. a mix of large & small switches combination,etc...

Depending on your aplication sizes, and generally speaking, I would go for no more than 12 clients in a 10BT segment, Cisco has a great interface module for the Catalyst 5000 switch, is a 4 ethernet switched ports including (in the same board) 4 managed hubs, each hub supporting 12 users/segment. So in this config, with a Cat5000 you can install 4 of those interfaces, for a total of 192 ports. 12 users/segment. single box, 2 100BT ports for links to other switches, and that CAt 5000 box + 192 users is about $24,000,00

Only if you need 12 user/10Mbps segment this config is very cost effective, about $125 per user including switch and managed hub.

Try data.com for reviewing the latest performnance tests on FAst Ethernet nics, look in browse by technology,

Best Regards

Roberto ****************************************************************** Roberto Gutierrez La Nacion S.A. (largest and leading newspaper in the country) Technology Asistant - Information Systems

Newspaper electronic edition http://www.nacion.co.cr

Tel (506)247-4200 Fax (506)247-4195 San Jose, Costa Rica ******************************************************************



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