Hurricane Electric's IPv6 Tunnel Broker Forums

Tunnelbroker.net Specific Topics => Questions & Answers => Topic started by: NewtonNet on March 24, 2010, 10:03:29 AM

Title: Calculation mechanism behind the Tunnel Latency Stats?
Post by: NewtonNet on March 24, 2010, 10:03:29 AM
Hi,

A question borne out of idle curiosity if I may... How are the figures calculated for the Tunnel Latency Stats (http://tunnelbroker.net/usage/tunnels_by_latency.php) page?

I understand that the latency is periodically measured from the relevent tunnel server - presumably by sending pings? If so, how many and when? Are multiple pings sent in succession to account for any pre-connectivity lookups (Layer 2 addressing) etc that would otherwise skew the results?

Again, just curiosity that's all..  :)

Mathew
Title: Re: Calculation mechanism behind the Tunnel Latency Stats?
Post by: broquea on March 24, 2010, 10:15:41 AM
Once a week, the client side of the v6 tunnel is pinged 5 times from the tunnel-server, and the average is the result stored. They are scheduled for early AM, Pacific Time.
Title: Re: Calculation mechanism behind the Tunnel Latency Stats?
Post by: NewtonNet on March 24, 2010, 10:18:47 AM
Ah okay, thanks!

Mathew
Title: Re: Calculation mechanism behind the Tunnel Latency Stats?
Post by: snarked on March 24, 2010, 12:55:48 PM
I would suggest that the pings not be exactly weekly, but every 6 or 8 days.  The reason for the variance is to avoid hitting the same weekly time and thus being skewed by any weekly cron jobs that [client] tunnel endpoint machines are running.  By being an even number, test time also slips around when we have odd months (months with an odd number of days).