Quote:
Originally Posted by roughbeast
Yes all of us agree with that I think. 4 people are less likely to be using the system all at once than 2 people, whatever the size of the pipe. Someone is more likely brewing a cup of tea or taking a dump. It makes sense, for statistical reasons, to put more people in bigger pipes than spreading them over a number of smaller pipes.
You feel that Ignitions logic regarding size of nodes is to have smaller ones to increase capacity, which appears to be contradictory to the above logic.
Well I am sure Ignition can square that logic somehow by pointing out some misconception you may have.
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Yes, reducing node size doesn't reduce the total bandwidth available it reduces the amount of modems sharing it and increases capacity per modem.
Splitting a 1000 home node (more accurately called a service group) with 400 active customers on it, for the sake of argument all on the DOCSIS 3 network served by 4 downstreams and 2 upstreams, 200Mb down and 2 x 18Mb up into 2 x 500 home nodes both of which will also have 4 downstreams and 2 upstreams doubles available bandwidth per home passed and improves statistical contention as the cohort size is smaller, from 400 to 200 modems.
Yes it still takes only 2 x 100Mb users using their full capacity simultaneously to saturate either node, but if there were say 8 100Mb customers on the 1000 home node and there's only 4 on each of the 500 home nodes the maths looks much healthier.
---------- Post added at 13:59 ---------- Previous post was at 13:55 ----------
Quote:
Originally Posted by roughbeast
Meanwhile, I do not understand why, if on the Coventry trial we had a 10Gb pipe in reserve, more capacity cannot be put in from the centre. Here I reveal the fact that I need to do some reading. I do know that Coventry was chosen for the trials because it had spare slots at street level.
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There was some spare room on the RF network at Coventry for the extra 8 downstreams and 2 upstreams you guys were provided.
The 10Gbps was to ensure that you guys wouldn't run out of core bandwidth.
The issue is, and remains, the DOCSIS downstreams and upstreams that serve the areas, 10Gbps or 1Gbps is irrelevant if there's only 800Mbps hitting the uBR, and having the extra room out of the back of the uBR is pointless for congestion relief if an area's DOCSIS network is overloaded.
The bottleneck is usually that last few hundred metres, not the core network, so anything past that bottleneck doesn't help. You still connect to the uBR at 200Mbps-400Mbps shared between your node / service group however many 10Gbps backhauls come out of the back of it.