Comcast/Level3 issues

Scott Berkman scott at
Fri Jan 3 15:55:04 UTC 2014

Comcast having saturated links to other providers is a common and 
frequently discussed issue.  Here is one previous NANOG thread on the topic:

And a related article:

There are debates back and forth on the validity of the graphs from the 
NANOG post, but it is a fact that at that time Comcast was heavily 
pre-pending their Level BGP advertisements to force traffic over to 
Tata, and many many people noticed congestion at those links in a 
variety of markets.

I wish you luck, but my personal opinion is that your fastest resolution 
would be to move to another provider.  Comcast is a residential ISP that 
lives on extreme over-subscription and not actually being able to 
deliver what customers believe they have. You'll notice a lot of recent 
news about increased and more strict data caps for their subscribers, 
and that is the only thing they will likely be doing to relieve these 
types of recurring issues.


On 01/02/2014 11:18 PM, R W wrote:
> I'm seeing the same as well. Can anyone from Comcast/Level(3) reach out to me or provide comment. We're seeing heavy jitter and some packet loss most noticeable in NYC area connections between Level(3) and Comcast.
> -Rob
>> Date: Tue, 31 Dec 2013 09:45:00 -0800
>> Subject: Comcast/Level3 issues
>> From: dwheet at
>> To: nanog at
>> Looking for a networking contact at comcast and/or level3.  I've been
>> having some slow speed issues with hitting some sites that's going through
>> level3 and I think there might be some congestion.
>> Doug

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