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New Member

How to tell if we need more bandwidth

My VP wants me to determine if one of our Frame connected sites should increase their Fractional T1. They are running our Accounting App accross the 128k Frame circuit and complain that the app runs too slow to be productive. We have MRTG running (I didn't set it up), but it doesn't show the circuit being taxed. MRTG showes the maximal out byte count over the last month was 14.919k, or 7.77% and the maximal in byte count was 5.332k, or 2.78%. Based on these numbers, I can't justify the upgrade. I am confident increasing the bandwidth will help. What other parameters can I look at that would suggest the circuit is too small? Thanks.

New Member

Re: How to tell if we need more bandwidth

Are you saying that your max out was 14k and max in was 5k? Those numbers just don't sound right........first, I would try pinging the app server when no one is using it (late at night), then ping it when users are complaining. The round trip ping times will be your latency....the ones under no use are your baseline numbers, and with use are actual numbers. The numbers should not be significantly different....if they are, you must find out why.....try pinging from router to router.....if those times are way off, then the problem is the circuit....if not, try pinging workstation to router......workstation to far end router. Keep going until the delay crops up.......

Good Luck

New Member

Re: How to tell if we need more bandwidth

Several things here. Start by clear counters and start from scratch. This will reset the counters to 0, its easier math to now calculate performance. Also at best MRTG polls every 5 minutes depending that the cron was set up properly. Make sure the crontab reads 5,10,15,20(you get the picture) * * * * /bin/mrtg/wherever mrtg is.

There are other bandwidth measureing tools out there just search google.

Hope that helps.



Re: How to tell if we need more bandwidth

One critical question is if the accounting application has ever run adequately... There are many applications out there, particularly on PCs, which assume negligible delays, which may be a good assumption on an empty Ethernet, but definitely not a good assumption on a WAN. It can be amazing what a few extra milliseconds of delay will do to an application which assumes it can read a file by requesting one record at a time and not requesting the second record until the first has been delivered...

If this is the problem, you will probably find that even a point-to-point T1 will not provide acceptable performance, leaving you between a rock and a hard place with the equally unsavory options of massively overbuilding the network (T3s are not cheap, and may be your only choice is not in an area with alternative long distance LAN service) or moving the server for the Accounting App back out to where it is being used or replacing the Accounting App with a better written application.

Good luck and good hunting!

Vincent C Jones

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