From: BIG-REQ@SUVM.BITNET
Newsgroups: bit.listserv.big-lan
Subject: BIG-LAN Digest, Volume 4, Number 68, Friday, October 16, 1992
Date: 16 Oct 92 14:49:01 GMT
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU

BIG-LAN DIGEST           Friday, 16 October 1992       Volume 4 : Issue 68

Today's Topics:

                  Is there value in Network Monitoring?
             Network availability targets/guarantees/policies
                            Multi-Port Bridges
                              Network Modems

Moderated by John Wobus, Syracuse University

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Date: Tue, 13 Oct 92 08:27:03 PDT
From: cook%bluemoon@hub.ucsb.edu   (Steve Cook x4753)
Subject:      Is there value in Network Monitoring?

The College of Letters and Science at UC Santa Barbara installed,
over the last two years, networking throughout several buildings
to many of the departments in the College.

Hardware was selected based on several factors, one of which was
the ability to remotely monitor the status of devices over the network
(hubs, repeaters, etc.) and gather performance statistics.  The
thought at the time of purchase was that there would be value in
both knowing when failures occur, but more importantly, analysis
of component performance and bandwith utilization over time would
provide insight into equipment reliability and advance, or premptive
information about pending failures.

We have the operational monitoring almost implemented, but know there
will be an initial cost and continuing cost to the statistical monitoring.

I need to build a justification for the on-going monitoring and
analysis of these networks.

Can anyone who is doing monitoring and analysis please send me
information about their experience and any benefits?

Thanks
Steve Cook
Computing Coordinator
College of Letters and Science
UC Santa Barbara
Santa Barbara,  CA  93106
cook@bluemoon.ucsb.edu
805 893-4753

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Date: Tue, 13 Oct 92 13:27:18 -0400
From: William H. Magill <magill@dccs.upenn.edu>
Subject:      Network availability targets/guarantees/policies

>       ... It has grown
>   from being almost a personal project to something that many people in
>   the university community now consider absolutely vital. ...
>
Boy is this an understatement! On any campus which actually uses networking
(ie one in which networking has existed for more than about a year)
not only is it considered vital, but it has become MISSION CRITICAL!!!
[Of course nobody in the organization will either admit to this fact or
even hint that it is true.:)]

>   Such numbers are a two-edged sword.  If you can get general agreement on
>   them, then you have a better chance of getting the necessary funding to
>   provide the necessary level of service (spares, level of maintenance
>   contracts, UPSes, personnel, overtime, diagnostic tools, etc.).  However,
>   you don't probably don't want your compensation tied to meeting a 99.99%
>   uptime requirement, either.
>
One of the largest fallacies running rampant in the "computing community" is
that "networking will save a company money."
"Networking" can NEVER EVER save a company money.
Simply put, they don't have a network today, so how can they save money
putting one in - it costs money to install, operate and maintain ANYTHING.
[Who they go'a fire - the mail room boy that runs around with the
intramural mail?]
What "networking" WILL DO is to allow a company to make more money by
allowing people to do things which they cannot even conceive of doing
today. "Networking" WILL change the way a company does business - it must.
[Nobody has ever figured out what "networking" means either.:]

This is why I say that in any environment which has had networking for
about one year it is now MISSION CRITICAL. The company has become ADDICTED
to it.  The classic case in point is the Financial Community (pick your
favorite part.) It CANNOT exist today without computing power. It simply
CANNOT use an "infinite number of monkeys" in green eye shades to accomplish
the work load which exists in a single business day. They simply can't go
back to paper and pencil.
Apply this to the "boss" who maintains an on-line calendar. If she can't
dial in and access that calendar from home at 5am - you will get an
"inquiring" message in your Electronic in-box when she can!

>   I would be interested in hearing from anyone else who has gone through
>   such an exercise.  How did you arrive at your targets (survey the
>   community, pull it out of the air, or what?)?  What are your targets
>   (95% availbility, 98%, 99%, 99.99%, etc.)?  Anything else you think is
>   relevant?
>
What does this mean in terms of uptime requirements - you have it
backwards. How much down time can you tolerate is the important
question. 98% uptime means that you guarantee that 2% of the time, the
network will be unavailable.

Lets see how this works out. 24 X 7 = 168 x.02 = 3.36 hours.
Now on the surface 3.36 hours a week that your network is guaranteed to be
down doesn't sound like much. But can you tolerate an outage that begins
at 09:15 on a Monday morning and lasts until 12:45? Clearly, such an outage
is a much larger threat to your compensation package, than the same outage
12 hours later!!! (Unless of course your payroll system runs in the off
hours.)

So I think you may begin to see my point. A campus computing network MUST be
available ALL THE TIME! 24 x 365.25 Anyone who actually is paying attention
to your numbers will see this pretty quickly. (Which is also a way of
saying that most management's will never notice your statement) so why
bother making it in the first place.

You need to assure management that you have the most Available, Reliable
and Maintainable (ARM - to steal the acronym from the now defunct Univac
Corporation) network you can provide. And that this you will keep
functioning and make  certain that you are doing everything possible to
assure that availability is maximized, any outage is minimized and that
within  constraints of your budget you can guarantee that WITHOUT a spare
Cisco Router as a hot spare  (the central point of failure in your network)
that it will take at least 24 hours to have a new one air-freighted to you.
AFTER you have determined what part needs replacing.

Make certain that your stock of spares includes lots of bailing wire,
chewing gum, pots of orange smoke and mirrors.

T.T.F.N
William H. Magill                         Manager, PennNet Computing Services
Data Communications and Computing Services (DCCS)  University of Pennsylvania
Internet: magill@dccs.upenn.edu                   magill@eniac.seas.upenn.edu
          magill@upenn.edu

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Date: Tue, 13 Oct 92 13:40:57 -0400
From: William H. Magill <magill@dccs.upenn.edu>
Subject:      Multi-Port Bridges

>   Date:         Thu, 27 Aug 1992 15:23:34 EST
>   From:         Bob Gentile <RGENTILE@WCU>
>
>The concern that we have with multi-port bridging is that broadcasts
>will be sent across all the segments.  Multi-port bridges will do filtering,
>and "learn" paths between devices, which can help reduce broadcast traffic.
>SNMP will help control broadcast storms.  Is this enough control?  Is it worth
>paying 3-4 times as much for a routing solution?
>

How will SNMP help control broadcast storms?

SNMP is Simple Network Management Protocol.
It is primarily concerned with the GATHERING of statistical data.

Depending upon your NMS (Network Management Station) you may or may not be
able to get useful information from more than one vendor's equipment.
(Note. I said useful data. It's easy to send an SNMP query and get back
an ANS.1 data string. The trick is in interpreting the information.)

As for "control" - yes you can do some control with SNMP.
BUT and this a BIG one - SNMP IS IN-BAND.
This means that in the middle of a broadcast storm, which is taking down
your network, you are intending (expecting) to be able to use that very
same network to first identify and then control the device causing the
problem.

And both of these statements ignores the fact that certain equipment,
Cisco routers I know for one, simply disregard any SNMP queries any time
the box gets "loaded." They reason - rightly or wrongly, depending upon
your point of view - that it is more important to "route packets" than
to answer some diddle question about "How many packets did you route in the
last 30 seconds?"

Again this fact means that at the one critical time you need it - when you
have an overloaded network - you have no SNMP management capability.

SNMP is an important tool. But, just as you CAN drive a nail with a pair of
pliers, that's not what they were made to do.

T.T.F.N
William H. Magill                         Manager, PennNet Computing Services
Data Communications and Computing Services (DCCS)  University of Pennsylvania
Internet: magill@dccs.upenn.edu                   magill@eniac.seas.upenn.edu
          magill@upenn.edu

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

Date:        Thu, 15 Oct 92 14:01:27 EST
From:        Charley Murphy <URMC@MARISTC>
Subject:      Network Modems

We are looking at integrating modem service into our current campus
LAN. Our network is token ring and IBM OS/2 LAN Server. We are
interested in company and product information to help evaluate
Async Communications Servers. We would also be interested in any
evalustions which other sites have done to provide modem service
to network users.

We are forced into this because our telephone system is a ROLM
digital switch, and analog service is not longer available to
offices or student rooms.

Thanks in advance.

Charley Murphy
Network Administrator
Marist College

Phone:     914-575-3252
Bitnet:URMC@MARISTC.BITNET

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End of BIG-LAN Digest
*********************
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU