common method to count traffic volume on IX

[niels=nanog at bakker.net (Niels Bakker)]

* nick at foobar.org (Nick Hilliard) [Thu 19 Sep 2013, 01:38 CEST]:
>On 18/09/2013 23:55, Niels Bakker wrote:
>>Ding ding ding!  And that's why honest IXPs graph both, to show 
>>that they have no packet loss on their inter-switch links.
>If in > out, it's not necessarily inter-switch packet loss.  The 
>difference between the two will also include packet loss for 
>same-switch egress traffic on customer ports.

That's absolutely true, I was a bit too glib in the quoted mail.


	-- Niels.