[Bloat] dslreports ping every second?

Dave Taht dave.taht at gmail.com
Sat May 2 12:25:36 EDT 2015


In one of the threads I saw that the dslreports test is one http ping
every second. I am not really sure how that is handled - if the
connection is
tcp (?) and persistent, that measures 1 packet RTT, if it is a new
connection, it is quite a few RTTs.

And it is really not enough pings for valid statistical sampling.

IF tcp, It would be vastly better to attempt a tcp ping every 10ms on
an established connection (or whatever can be achieved, with 20ms
being a good interval for most voip, 100ms seems easily doable,
but...). This would accomplish two things:

1) A single packet loss would not cause a RTO (usually 250ms) but be
flushed out (resent) on the next packet sent. So you would see replies
get bunched in relation to loss and delay.

2) More pings more accurately track actual latency over a much tighter
interval in general, particularly during the slow start phases at the
beginning of the test where things tend to get really out of hand when
you fire up tons of flows.

In terms of plotting, I am quite fond of smokeping's methods, so you
could still show the bar chart on a per second basis, but colored as
per smokeping.

(It had been my hope to one day leverage the webrtc apis to be able to
test udp.)

On what interval is it feasible to fire off a new http ping, and can
the difference between a persistent connection and a new one be
determined from within the browser?


-- 
Dave Täht
Open Networking needs **Open Source Hardware**

https://plus.google.com/u/0/+EricRaymond/posts/JqxCe2pFr67



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