One-way delay measurement for netperf-wrapper

Hal Murray hmurray at
Mon Dec 2 00:45:26 EST 2013

toke at said:
> - Is clock drift something to worry about over the timescales of these
>   tests? 

It depends.  :)

How long are you running the tests?  How accurate do you expect the timings 
to be?

ntpd assumes the network delays are symmetric.  It's easy to break that 
assumption by sending a lot of traffic in one direction.  ntpd tries to avoid 
that problem.  It remembers the last 8 packets to a server and uses the one 
with the shortest round trip time.  If you run tests for long enough you will 
overflow that buffer.  The time scale is somewhere between minutes and hours.

These are my opinions.  I hate spam.

More information about the Bloat-devel mailing list