Pete, I got your direct message but I cannot reply to u for some reason.

In reply to a post by WWWombat:

Really interesting...If the CMTS are all co-located in a few hubsites, what does the path look like between the user and the CMTS? How much is fibre, how much is coax, and what kind of distances?

And ... what changes in that path when re-segmentation (of whatever variety) is needed? What bottleneck adjustments get made?

Answering point 1 the distance between hubsite and the end of the fibre, the fibre optic node somewhere in the neighbourhood, can go up to 100 miles in the specifications but, obviously, running it close to that limit is a bad idea due to propagation delay changing due to environment.

Certainly runs of 40km+ of fibre aren't uncommon.

Answering number two it depend on the construction of the network. It's basically variations of splitting a node, physically or logically, by addition of fibre, with each fibre then leading back to new line card capacity.

Physical splits involve building new nodes, which may need to be deeper into the coaxial network, like an Openreach type FTTRN set up. Logical ones are where a node has 2 or 4 coaxial trunks out and a single fibre pair in, delivering more fibre pairs to reduce the number of homes passed by each fibre pair.

There's another kind of split which is where a node is optically combined. If the fibre is pretty deep it makes sense to combine nodes optically and have a single line card port feeding both of them. That is split by removing the combining so that each node then has its own dedicated fibre to hubsite, and removing the combining at the hub so that each node has its own line card ports.

That a simplification, I didn't want to go into modular CMTS architecture, CCAP etc. It'll do

In reply to a post by TMCR:

In reply to a post by Ignitionnet:

Areas are covered by multiple hubsites, customers don't necessarily connect directly to headends, these are a slightly different beast from the hubsites where most of the CMTS are.

I think this explains a little about my area, Doncaster has always been on a feed from Barnsley, it does not seem to have it's own head ?

As far as the broadband goes Doncaster and, indeed, Barnsley, are fed from Bradford.

EDIT: I should clarify both have their own hub sites with their own CMTS for the cable modems to connect to. The CMTS then go back to Bradford, and in turn Bradford will probably go to Leeds and Manchester to get onto the VM backbone.

9 brad-core-2b-ae17-0.network.virginmedia.net (62.254.42.254) 19.897 ms 20.077 ms *
10 donc-cmts-12.network.virginmedia.net (82.7.207.80) 23.170 ms 23.582 ms *


9 brad-core-2b-ae17-0.network.virginmedia.net (62.254.42.254) 19.970 ms 20.106 ms 20.298 ms
10 * * barn-cmts-01-ge01.network.virginmedia.net (81.97.83.133) 21.380 ms

Edited by deleted (Tue 10-Nov-15 18:05:55)

In reply to a post by Ignitionnet:

As far as the broadband goes Doncaster and, indeed, Barnsley, are fed from Bradford.

Before Telewest days it was Bradford Cable, that sums it up I guess.

I called and got them to up me 2 days ago, this is the start of some tests

New 200mbps Test Results

Have a try with this tester as well : http://www.dslreports.com/speedtest This is also a multi-thread test

Remember and select the ' Cable ' option when deciding connection type.

.....................

My Vivid connection atm: http://www.dslreports.com/speedtest/1918100

There was a user where that test reported faster than us, but turned out there was a configuration issue on the Virgin Media connection, which was swamped when using 24 downloads at once.

6 downloads is more than enough for even a Gigabit connection

In case the issue is a Flash bottleneck our other tester at http://labs.thinkbroadband.com/speedtest is worth a go.

i get the same pattern of bandwidth on my networx bandwidth monitor graph as i get from the results using the dsl speed tester ..

it's the same when using the tbb one as well. the pattern on the graph on networx almost mirrors the ttb results graph. only problem i am finding is the tbb one is all over the place.even when doing tests at 3-4 am as an example. it's kinda weird and unsure what's cauising it.

i will do 3 dsl tests and 3 tbb tests one after the other :

http://www.dslreports.com/speedtest/1918883 215/12

http://www.dslreports.com/speedtest/1918898 196/12

http://www.dslreports.com/speedtest/1918912 203/12


now using the tbb speed test link you supplied :

http://www.thinkbroadband.com/speedtest/results.html... 99/13

http://www.thinkbroadband.com/speedtest/results.html... 135/13

http://www.thinkbroadband.com/speedtest/results.html... 98/13


Something a bit strange somewhere... but as i said a min ago when i look at my networx graph as each test is getting done it shows the exact same pattern as the end result from the speed test

The DSLReports tests are far from perfect and that is with 24 downloads running. The numbers displayed may be nice, but look at the graph and you can see a lot of the time you are only seeing transfer rates in the 100 to 160 Mbps region.

So if we quadrupled the number of downloads we would like show the same, i.e. DSLreports is a LOT less sensitive to congestion and that is our aim to provide a tester that is close to what you are experiencing.

By doing more downloads at once you actually grab a larger share of the shared bandwidth that is available locally, and thus graphs should be a sharp rise initially and a flat throughput there after.

http://tbb.st/144648127699210632592 a good flash example
http://www.thinkbroadband.com/speedtest/results.html... a good test, though they did have a small dip in the speed at the end.

So both testers are doing things right, and seem to be reporting correctly, the issue is why your speeds are a bit variable. If you try a specialised single thread download version you should be able to see the variation.

On a good clean connection and decently configured TCP/IP stack and reasonable PC over Ethernet no reason that single thread download should not be able to fill a 200 Mbps connection.

Thanks for getting back Mr S.. i wish i had more time to reply but in the middle of something atm ..

i am not saying the tbb test is borked and i am also not saying that the dsl one is 100% correct either.. now i could be wrong here and most of you guys know a lot more about things like this than i do lol

my network monitor measures the data moving through my network card at any given time yea ? it is independent from the speedtester of choice ? so if i base my connection speed when maxed out on the live real time graph i can see what the speed of data is in Mbps .

when doing speed tests on tbb or dsl or speedtest the graph on the monitor shows what data is flowing through the network card and it matches the graphs on the speed tests

so if dsl is saying im getting 198 then its the same on the monitor

if tbb says 134 then its the same on the monitor as well

so if any one of the testers is borked and not giving true results ? how is it possible for the monitor to also report that the same amount of data passed through the netowrk card at the same time as the test was done ?

i can't get my head round how that is possible



Sorry for the quick reply and you are a brave man if you read it before lunch


Edit : i never got this problem when i was on the 152 product before the Vivid upgrade .. nearly every speedtest on tbb was spot on.i was getting 160/12 90% of the time 247.and the monitor was showing the same ( if i had a penny for every time iv said monitor ) .

Edited by djfunkdup (Thu 12-Nov-15 12:51:33)