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Old 20-04-2006, 23:44   #14
dragon
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Re: Upgrade to 10mb from 2mb - now worse off :(

Quote:
Originally Posted by Chrysalis
Yes when capacity isnt upgraded by the same margin.

If you increase the max burst speed to each user by 500% (2mbit to 10mbit) then if you dont increase the shared bandwidth pool by the same margin you are also increasing contention ratio and as such actual bandwidth per customer drops.

So an example I could give is you have a load of customers on 2mbit, the actual bandwidth to each customer is 400kbit but because of light users they are able to fully burst and as such they all happily getting their 2mbit and their is some spare bandwidth leftover. Now upgrade these users free of charge but leave the shared bandwidth pool the same size, so you now have customers who can burst to 10mbit and still have 400kbit actual bandwidth, most of the light users still use the same but the heavier users find they can use more, so now contention is biting and it isnt possible to hit 10mbit and because of increased contention the 2mbit is no longer acheivable.

I think some people wont agree with me on this tho, BT,NTL and loads of other isps have started scrapping contention ratio figures to try and hide whats going on.

---------- Post added at 00:16 ---------- Previous post was at 00:12 ----------



Whats your explanation for the SACM 250 users?

Chrysalis i think the question was more to do with the fact that now hes on the 10mbit service why does he get slower speeds than when he was on the 2mbit service.

i understand that theres a shortage of bandwith for the 10mbit service but how come you can get a stable connection if your on the 1 or 2mbit yet you get slower than 2mbit on the 10mbit

are they keeping the 10mbit users on a different channel to the 1 and 2mbit ones or something.
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