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Originally Posted by monkey2468
Never really understood why upgrading some peoples speeds actualy give a decrease in speed. I can't think of any technical reason. Does anyone have a theory or answer as to why this might occur?
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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 ----------
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Originally Posted by Druchii
My theory is that the STB is trying its damned hardest to use the extra bandwidth available to it, and as such is actually perfoming worse off. Whereas if they eft the config how it was until the modem was in place it would have been different.
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Whats your explanation for the SACM 250 users?