Some truth about Comcast - WikiLeaks style

Adam Rothschild asr+nanog at
Wed Dec 15 16:47:09 CST 2010

On 2010-12-15-12:15:47, Kevin Neal <kevin at> wrote:
> Also assuming the backbone and distribution upgrades required between
> their data centers and their customers costs nothing.  It's not free
> to get bandwidth from Point A (port with TATA) to Point B (Customer).

I don't see how this point, however valid, should factor into the
discussion.  Missing from this thread is that Comcast's topology and
economics for hauling bits between a neutral collocation facility and
broadband subscriber are the _same_ whether they ingest traffic by way
of a settlement-free peer, customer, or paid transit connection.

Speaking to Richard's earlier observations, we too have run into
issues attempting to deliver content by way of Comcast's Tata transit,
dating back to July of this year.  (It's possible the issues might
have begun sooner, however this is as far back as our analytics go.
I've actually been spending some time documenting how we've been
measuring this loss, and how folk might measure it on their production
infrastructure utilizing policy routing, routing-instances, and the
like -- any interested content folk are welcome to contact me
off-list.  Suffice it to say, configs are the easy part, the hard part
is building a statistically valid sample set without degrading
connectivity for paying customers...)

Whatever the cause, five months should be ample time to turn up some
additional transit capacity or otherwise work around the issues; we're
talking commodity transit ports in neutral facilities, such as Equinix
sites, after all.

What we have here is Comcast holding its users captive, plain and
simple.  They have established an ecosystem where, to reach them, one
must pay to play, otherwise there's a good chance that packets are
discarded.  Alternate paths simply aren't there, given the no-export
communities deployed.  As it stands, I could multi-home to NTT, Telia,
Tata, and XO, and still get stuck with no good paths to Comcast.
While this has happened before (see: DTAG, FT, ...), this is probably
the first we've seen it occur in the United States, at scale.  Folk in
content/hosting should find this all more than a little bit scary.


More information about the NANOG mailing list