Sleepless in Cologne - But At 16 MBit/s

Back in August last year my last UTMS speed measurement at home resulted in a sustained peak data rate of 11 MBit/s. Since then, things have moved forward once again so it was time to perform another test, this time at 3 am in the morning once jet-lag caught up with me. And I was not disappointed, the sustained data rate was over 16 MBit/s as shown in the picture on the left. If you put the 10-15% of HARQ overhead on top that's just 2.5 MBit/s below the theoretical maximum speed of 21 MBit/s (again including HARQ). Performing the same test again in the morning resulted in around 14 MBit/s a second. Breathtaking values!

Comments

[Andy]

Hi Martin,

Breathtaking indeed..

Have you done any TCP/IP parameter optimisation on the client or server side to maximise the throughput? Is the server located in Germany itself?

Also I'd be interested in the latency values you're seeing. Previously you had achieved 60ms. Was this to the same server and what was the packet size?

[mobilesociety]

Hi Andy,

No TCP/IP parameter optimization whatsoever, I just took the default from Ubuntu. I would expect that Windows Vista or 7s default stack settings would have given a similar performance as they also adapt the TCP window size. Yes, the sever is located in Germany so short RTDs. And latency was, as you say around the 60ms mark to that server.

Cheers,
Martin