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VDSL50 by T-Com

Today, I finally got VDSL. Actually, I was supposted to get it 2 weeks ago, but T-Com managed to have a shortage on the VDSL2 hardware (and refused me to pick some up from one of their stores where there was hardware) and then after I got the hardware, they needed 1 week to activate my VDSL2 line. I think I paid at least € 10 to call their support hotline preventing them to test what else can be done wrong. I wonder how long others had to wait. Anyway, I’m now a lucky guy who didn’t get VDSL25 but VDSL50 with 50Mbit down and 10Mbit up! So now, it’s time to test the line.

Well, my friend Patrick wanted to know the latency, so I first pinged some servers:

heise.de 30ms
qianqin.de 31ms

The connection was pretty stable and until now, I have nothing I can complain about.

Next Patrick downloaded an endless file from my apache2. Speed was around 1.2 MB/s, which is around 9 Mbit. Upload seemed just fine. Patrick, btw has a Alice DSL line with 16 Mbit down. Now the Download part, I did some speed tests online, but they all only reached around 20 Mbit. I tried to download a file manually from my 100Mbit server and reached around 1.6 MB/s, which is only 12 Mbit. I don’t really care about the download speed, but this was kind of disappointing. But I will do some further tests later and report them here.

3 Responses to “VDSL50 by T-Com”

  1. cybercake:


  2. Gast User:

    Wenn die Download Geschwindigkeit niedriger ist als aufgrund von VDSL-25 oder VDSL-50 zu erwartet ist, so muß das nicht an der Telekom liegen. Grund können die TCP/IP Parameter des Betriebssystems sein. Die Parameter heißen auf den verschiedenen Betriebssystemen jeweils anders, aber Google hilft. Ich konnte auf meinem OS die Download Geschwindigkeit von VDSL-25 von 1,5 auf 2,6MB/sec steigern.

  3. Qian Qin:

    Ich gebe dir Recht, denn unter Windows XP muss man die TcpWindowSize modifizieren, damit man überhaupt über 5MBit (bei 100ms round trip) kommt, aber unter Vista gibt es die Einstellung nicht mehr. Vista ändert selbstständig intern die Fenstergröße, um den Durchsatz zu optimieren.

    Infos hierzu bei MS Technet