I would be happy to run pingplotter for longer to said servers, but ICMP latency isn't the issue; throughput is. Do you think the CDNs in question could be the issue?
The trouble with this kind of selective congestion: I can't easily tell if Comcast is running hot ports (something that is often alleged and sometimes backed up, like in the Tata case from awhile back) or if the CDN is performing poorly.
I'm having trouble with providers that *aren't* serving me Netflix (that's always Level3). I'm not a particularly savvy user so I don't know of ways to gather conclusive data that would support my conclusion. Help would be gratefully received, because from what I've observed, there's an issue.
If there were a problem in the network portion you would probably see latency/loss starting at a hop AND CONTINUING all the way to the destination. Seeing a problem at one hop that does not continue is not a problem and seeing no issues along the network path tends to implicate the server you are talking to.