common method to count traffic volume on IX

Wed Sep 18 22:55:27 UTC 2013

* bicknell at ufp.org (Leo Bicknell) [Wed 18 Sep 2013, 19:23 CEST]:
>On Sep 17, 2013, at 3:15 PM, Niels Bakker <niels=nanog at bakker.net> wrote:
>>I don't know of any IXP that does this.  Industry standard is as 
>>you and others wrote before: the 5-minute counter difference on 
>>all customer-facing ports, publishing both input and output bps 
>>and pps.  I guess MRTG is to 'blame' for these values more than 
>>anything.
>
>Serious question, at an IXP shouldn't IN = OUT nearly perfectly?

Ding ding ding!  And that's why honest IXPs graph both, to show that 
they have no packet loss on their inter-switch links.

(Or, much more likely, measurement errors due to wrong config for the 
grapher)

	-- Niels.