nanog mailing list archives

Re: Observations of an Internet Middleman (Level3)


From: Christopher Morrow <morrowc.lists () gmail com>
Date: Fri, 16 May 2014 10:17:43 -0400

On Fri, May 16, 2014 at 7:56 AM, Vinny Abello <vinny () 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.

are you measuring inside the (for this) comcast network or after your
cable-modem?
I recall that the cable-modem(s) often (by docsis config) impose some
qos markings on the lan-side of the connection.

I think they can do the same on the WAN side for traffic leaving your
site to the tubes... but you probably can't measure that as easily as
with wireshark on your pc.

-chris
(also, is there some other equipment between your wiresharker and the
cable-modem? could that equipment be re-marking/marking as well?)


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