Calculating Bandwidth Requirments

[ElijahBaley]

Hi

Not sure if this is the right place for this topic but I guess you Cisco people are the best!

Just wondered if any one could tell me the golden rules to calculating bandwidth requirements for WAN links, what techniques do you use in the real world?

Also how do you determine what technology to use (PPP dial-up, ISDN, DSL, PPP leased line, Frame Relay) what considerations do you apply.

Basically if you had to hook up a remote office to your corporate headquarters, how would you go about making sure you got a good cost/performance/quality set-up

Thanks for any help



..EB (Plainclothesman)

 

[LookAhead]

Hi EB,

with regards to the compexity of your question ;-)
1.) Try to evaluate the bandwidth-requirements by examining comparable locations. If you have a subsidiary with 20 users and you try to calculate reqs for another loc with 15 users, that could make sense. Important to know, if the usage seems comparable (no sense to compare 15 financial guys with 15 programmers

2.) Try to find out about bandwith utilization by installing tools that can give you a clue: MRTG, as one of the more popular tools, tells you about interface utilization of a specific link on a router interface (see:

http://people.ee.ethz.ch/~oetiker/webtools/mrtg/

or

http://www.mrtg.org)

3.) You might ask someone familiar with your network manangement system, if one is in place. They can give you summaries about utilization. Also try to get information from your software vendor. All the big ones, and even the smaller companies, support their clients with that information, e.g. SAP R/3 needs abt 12 to 16 kbps, CITRIX takes abt 16 to 20 kbps.

4.) Or you call some specialist with measurement equipment to give you hard facts. That might be expensive but gives you usually a much more detailled insight and helpful numbers. This is called "network baselining". see a good article at

http://www.networkcomputing.com/netdesign/base1.html

Kind regard
Gerhard

 

[ElijahBaley]

Thanks for your detailed reply Gerhard.

I do not actually have a project like this on the cards, I just want to learn a bit more about how this sort of work is carried out in aticipation of doing it one day!

Regards



..EB (Plainclothesman)