[ILUG] Slightly OT. The which ISP Question!
thomasb at gmail.com
Mon Feb 20 12:55:35 GMT 2006
On 2/20/06, Colm MacCarthaigh <colm at stdlib.net> wrote:
> Capping is mostly based on how much transit bandwidth costs, and
> unfortunately bytes cost money. And that's not just the money that goes
> to the transit provider either, it's all of the interface cards and
> routers and fibre costs in between too. These things are not cheap, they
> cost a lot of money.
At one point I did go to the trouble of calculating the cost of
transit based on a quote that Netsource had from a transit provider -
and I calculated that each Gb of data downloaded from the transit
provider cost at least 50c (in fact, that was much higher as I was
doing a lot of approximations to make the mental maths easier). Each
1 Mb/s allows a download of 324 GB of data a month, but in reality at
best that 1Mb of transit will be used at around 60% of that (averaging
accross 24 hours and weekends when only the peer 2 peer users will
maintain consistent transfer rates). If you call that 200GB of data
transferred per Mb of commit, that means your ISP is paying 50c a Gig
downloaded if the rate is 100 euro a meg.
Prices have gone down since then - now your ISP maybe paying 25c a Gig
as transit rates are about half.
This means that if you download 16GB of data, and your ISP is charging
only 10 euro over the eircom wholesale rate for the line, that leaves
the ISP with a 6 euro a month out of which it has to pay the
1. The cost of the interconnect with Eircom which is a seperate cost
from the line charge.
2. The cost of the tech support staff who are answering the phone
when you have a problem.
3. The cost of the network and server admins who run the rest of the
infrastructuer on which you depend on. And believe me, if you're a
business, you don't want your ISP making short cuts in how much they
4. The cost of moving the traffic from the interconnect point with
Eircom to the transit provider.
Not to mention other costs like INEX connectivity and a return on
capital investment like the cost of Cisco L2TP terminating devices
(and before anyone mentions Juniper and Redback, at lower volumes of
users that a typical mid range Irish ISP would deal with they are even
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