News:

Virgin Media / NTL:Telewest 50Mbps Trial

Virgin Media / NTL:Telewest have begun their 50Mbps service trials in the Ashford, Kent area. We're lucky enough to be one of the trialists. These News pages will be updated as much as possible with any relevant details that may be of interest to anyone.
The overall download speeds improve overall performance

Preamble

Virgin Media / NTL:Telewest have begun their 50Mbps service trials in the Ashford, Kent area. We're lucky enough to be one of the trialists.
The modem arrived during the day on the 27th February, I followed the instructions to install it; hardly very complicated,

  1. install the coax cable
  2. install the power cable
  3. install the ethernet cable
  4. refresh DHCP lease


It took approximately 17 minutes to obtain the frequencies for all 4 internal modems.
That's right! It has 4 modems and a network switch inside.

I did some initial tests which showed that the maximum speed I was getting from downloading a dvd iso of the CentOS Operating system was just over 10Mbps.
I next tried downloading the same file and 5 other DVD/CD isos, to try and find an overall speed. This proved benificial, as the total speed was equating to approximately 45Mbps, which with over heads and a few other bits of traffic on my network seemed reasonable.

I'm of the understanding that a single file can obtain a download speed of 50/4 Mbps = 12.5Mbps because of there being 4 modems inside. The guys at VirginMedia have told me that it should give me full speed on one download but not on uploads, but that doesn't seem to be the case just yet.

Ping Times

I ran a ping of 45 packets to see what the results would be, I firstly pinged the NTL gateway for my connection, the results were:

  • round-trip min/avg/max/stddev=5.796/8.629/27.980/3.621 ms
I then compared this to a ping of the same number of packets to one of our machines hosted in the Redbus Datacentre, Docklands;
  • round-trip min/avg/max/stddev=17.016/21.294/37.954/4.674 ms

Obviously higher results, because the machine is 11 hops away, (6 of which were still inside the ntl network), you can see by the standard deviation from the mean that this is a good comparison.

Operating System

We're using a custom FreeBSD installation as the router, tests were carried out directly from the router as well as from a Windows XP workstation within the network. There were no special settings required in order to get the FreeBSD machine connected at full speed to the network. I literally just had to refresh the DHCP lease after the cables had been changed to the new modem. No messing about with changing TCP/IP settings, no changes to MTU were required.


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