[ntp:questions] ARRGH!!! I woke up to a 50 SECOND clock error.

Uwe Klein uwe at klein-habertwedt.de
Sun Mar 18 12:02:15 UTC 2012


David J Taylor wrote:
> "Rob" <nomail at example.com> wrote in message 
> news:slrnjmbdn3.9ce.nomail at xs8.xs4all.nl...
> 
>> Uwe Klein <uwe at klein-habertwedt.de> wrote:
>>
>>> Regular DSL here has quite large and spread line delays
>>> though speed is much higher delay is similar or slightly larger than
>>> forex ISDN.
>>> PING 87.186.242.38 (87.186.242.38) 56(84) bytes of data. ( my first 
>>> pingable outside node )
>>> 64 bytes from 87.186.242.38: icmp_seq=1 ttl=254 time=48.3 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=2 ttl=254 time=34.3 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=3 ttl=254 time=77.4 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=4 ttl=254 time=70.8 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=5 ttl=254 time=108 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=6 ttl=254 time=89.0 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=7 ttl=254 time=109 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=8 ttl=254 time=64.1 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=9 ttl=254 time=76.1 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=10 ttl=254 time=145 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=11 ttl=254 time=199 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=12 ttl=254 time=104 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=13 ttl=254 time=247 ms
>>> 64 bytes from 87.186.242.38: icmp_seq=14 ttl=254 time=104 ms
>>
>>
>> Funny network...
>>
>> I can ping the same address over my own DSL and get lower and more
>> stable ping than you do:
>>
>> ping 87.186.242.38
>> PING 87.186.242.38 (87.186.242.38) 56(84) bytes of data.
>> 64 bytes from 87.186.242.38: icmp_seq=1 ttl=245 time=34.7 ms
>> 64 bytes from 87.186.242.38: icmp_seq=2 ttl=245 time=36.3 ms
>> 64 bytes from 87.186.242.38: icmp_seq=3 ttl=245 time=35.3 ms
>> 64 bytes from 87.186.242.38: icmp_seq=4 ttl=245 time=33.6 ms
>> 64 bytes from 87.186.242.38: icmp_seq=5 ttl=245 time=34.8 ms
>> 64 bytes from 87.186.242.38: icmp_seq=6 ttl=245 time=35.8 ms
>> 64 bytes from 87.186.242.38: icmp_seq=7 ttl=245 time=34.2 ms
>> 64 bytes from 87.186.242.38: icmp_seq=8 ttl=245 time=35.3 ms
>> 64 bytes from 87.186.242.38: icmp_seq=9 ttl=245 time=33.0 ms
>> 64 bytes from 87.186.242.38: icmp_seq=10 ttl=245 time=34.2 ms
>> ^C
>> --- 87.186.242.38 ping statistics ---
>> 10 packets transmitted, 10 received, 0% packet loss, time 9043ms
>> rtt min/avg/max/mdev = 33.069/34.776/36.339/0.943 ms
>>
>> Pinging something local in my provider yields stable pingtimes within
>> 13-14 ms...
>>
>> Maybe your provider still uses old ATM technology between the subscribers
>> and the DSL router, and the network is heavily overbooked.
>>
>> This is, however, not a generic property of DSL.   DSL can have stable
>> roundtrip times.
> 
> 
> .. and from Edinburgh:
> 
> ping 87.186.242.38
> 
> Pinging 87.186.242.38 with 32 bytes of data:
> 
> Reply from 87.186.242.38: bytes=32 time=43ms TTL=239
> Reply from 87.186.242.38: bytes=32 time=44ms TTL=239
> Reply from 87.186.242.38: bytes=32 time=46ms TTL=239
> Reply from 87.186.242.38: bytes=32 time=50ms TTL=239
> 
> Ping statistics for 87.186.242.38:
>    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
> Approximate round trip times in milli-seconds:
>    Minimum = 43ms, Maximum = 50ms, Average = 45ms
> 
> That's at 11:07 on a Sunday morning.
> 
> David
Deutsche Telekom. "Best speed optimised" over 4km of copper wire.
The variation were from my daughter using the connection for watching youtube in
parallel. ( NAT hidden home network. )

uwe



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