Observations of an Internet Middleman (Level3)

Livingood, Jason Jason_Livingood at cable.comcast.com
Fri May 16 14:58:57 UTC 2014

On 5/16/14, 7:56 AM, "Vinny Abello" <vinny at abellohome.net> wrote:

>I think he's questioning why packets from speedtest.comcast.net have CS1
>if everything is supposedly equal, and what that is used for. A quick
>Wireshark shows that to be true right now running to your Plainfield, NJ
>speedtest site, and my network peers directly with Comcast.
>I'm kind of curious too. What is the purpose of this? Is it the
>traditional purpose of CS1 to be less than best effort or something
>else? If this is the case it seems Comcast would be purposely putting
>themselves at a disadvantage in speed tests when congestion is
>involved... or is this possibly on purpose to make peering problems look
>even worse during congestion?

Ah! That makes sense now. CS1 is used internally to mark best effort
Internet traffic. This has often caused confusion when folks see our
markings. If folks want to send me any data off-list that you think merits
further investigation, let me know (never know if something someplace is
an honest config error).


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