IP DSCP across the Internet

Mike Hammett nanog at ics-il.net
Thu May 7 11:46:00 UTC 2015

That sounds like a rather poor implementation. What if they had more than one VoIP call? 

Seems like this thread has more FUD than real examples. 

Mike Hammett 
Intelligent Computing Solutions 

----- Original Message -----

From: "Mikael Abrahamsson" <swmike at swm.pp.se> 
To: "Mark Tinka" <mark.tinka at seacom.mu> 
Cc: "nanog list" <nanog at nanog.org> 
Sent: Thursday, May 7, 2015 4:32:52 AM 
Subject: Re: IP DSCP across the Internet 

On Wed, 6 May 2015, Mark Tinka wrote: 

> With color-aware policing toward a customer in Uganda, any traffic 
> coming from that peer in South Africa was getting dropped toward that 
> customer in Uganda. After a very odd sequence of troubleshooting events, 
> we found that the AF DSCP alues being set by the peer in South Africa 
> (and us passing them due to the old kit not being able to remark on 
> ingress) was causing the color-aware policer in Uganda to drop traffic 
> toward the customer there. 

I have heard similar stories where game traffic ended up in a 100 
kilobit/s VoIP queue which worked fine until there were a lot of nearby 
players in the game, then things started working very badly. Also nice 
corner case :P 

So yes, setting all external Internet traffic to DSCP=BE (0) is something 
one wants to do. 

Mikael Abrahamsson email: swmike at swm.pp.se 

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