[ntp:questions] Befuddled and confused, again...

David Lord snews at lordynet.org
Tue Feb 16 14:14:25 UTC 2010


Rob wrote:
> David Lord <snews at lordynet.org> wrote:
>> David Woolley wrote:
>>> David Lord wrote:
>>>> Systems seem heavily overloaded.
>>>>
>>>> My 3G mobile broadband has seconds of latency whilst initiating
>>>> connections, that is how the system works, maybe 10 seconds, but
>>> That's likely to be result of the power management design, not of overload.
>> No, connection is already established, PPP is already up and
>> routing all setup. Possibly ssh connected but no traffic.
> 
> He is correct, it is a power- and traffic management issue, not something
> unique to the UK.
> 

He's not correct

I ordered mobile broadband and order was rejected because
the network in this area is too congested and degrading
performance so I'll have to wait until next upgrade.

> There are some polling rates in the 3G protocol that adapt to the actual
> traffic.  When a connection has been idle for long, it can take some time
> to come back when you suddenly use it.  When there is occasional traffic,
> it will take around 400ms.  Once there is lots of traffic (more than
> a few packets per second), the roundtriptime will drop to 80-100ms and
> stay there until there is less traffic.
> E.g. pinging it at 1 second intervals will not keep it at the fast rate.
> Pinging 5 times per second (ping -i 0.2) will.

I was seeing what I wrote and can't care less
about contra examples.

 From today:
                rtt min/avg/max/mdev(ms)
ping -c 10 -i 5    168/384/626/128
ping -c 10 -i 1    150/303/1044/265
ping -c 10 -i 0.2  382/484/758/102
ping -c 10 -i 0.1  368/629/1222/297

Proves your point?

David




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