Strategic Bandwidth Planning

Posted on 2008-11-18
Last Modified: 2013-12-14
Have you run across any formulas for determining when to buy more (ISP) bandwidth?  We are attempting to come up with a strategic solution.
Question by:RPPreacher
    LVL 13

    Expert Comment

    There are many models out there for calculating effictive bandwidth.
    I've seen per-user rates from 12k to 45k, with 22k being the most popular.

    These per-user rates are for large number of users.
    Mostly "normal" internet traffic (web, email, etc.) taken into consideration, anything like VOD or conferencing, VoIP, etc. can drastically affect the numbers.
    LVL 21

    Expert Comment


    First you need to monitor your actual bandwidth usage.

    You need to identify peak hour(s) at which bandwidth usage is highest (e.g. between 9AM and 10AM). Measure average bandwidth usage (not peak bandwith usage) during the peak hour(s).

    If average usage during peak hour exceeds a threshold of (say) 70%, you need to order more bandwidth.

    LVL 20

    Author Comment

    >average usage during peak hour exceeds a threshold of (say) 70%

    I'm more looking for what threshold most enterprises are using.

    We have network utilization numbers ad nauseum.  I was asking "what do you use?" rather than rely on "the network seems slow".
    LVL 21

    Accepted Solution


    Two numbers we use in general:

    -average peak should remain under 70%
    -average latency between you and your provider should remain under 30ms


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