Wednesday 22 April 2009

When 100MB isn't really 100MB at all

I just left this comment over at Andrew Bolt's place:

Always remember to read the fine print when someone says "up to", as in Kevni saying that it will offer speeds of "up to 100mb".

From the Concept Economics report:

committed information rate of 2 Mbit/s—which at a contention ratio of 50-1 provides for end user speeds of up to 100Mbit/s

Note the bit about the committed information rate - normally called the "CIR". That is the guaranteed minimum bandwidth that you will get - but at times of congestion, it is also the maximum that you will get.

So if you are sharing a 100MB pipe with 50 other people, you have a CIR of 2MB. If they are all asleep with their computers turned off, you get the whole 100MB to yourself. If they are all reading The Age online, you are choked down to 2MB.

In technical jargon, OneTel Mk II is capable of "bursting" up to 100MB speeds from a minimum of 2MB. It can only burst up to higher speeds if no one else is around.

There are lies, lies and then comments about network speeds.

Until today, no one has said anything about the CIR and burst capability of OneTel Mk II. I'm glad someone finally cottoned onto it.

By the way, if they built a network using the switches that I outlined in an earlier post, this wouldn't be an issue - but it costs a bomb.

The only way Kevni can promise low prices is if they build a cheap and nasty network that always talks about "up to". At present, I can get "up to" 1.5MB out of my existing ADSL link - but I almost never get anywhere near it.

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