briankb
If you're in southern California and looking for a residential internet service provider, I'd recommend avoiding ATT like the plague. After some testing, I am pretty confident they are now throttling my VPN traffic as of 04/25 regardless of what port or protocol I am using.
Here's what I did:
For example, I can scp a 100mb test file directly from a server using its public IP at a reasonable ~2MB/s. This is about the advertised speed from U-verse. If I scp the same file using the private VPN address of the same server (direct connection, no nat involved), the rate never exceeds 40kb/s. The issue still occurs even using different protocols and ports (TCP 443, UDP 5060, nobind, etc). An mtr shows no packetloss and no unusual routing, bandwidth tests show no bottlenecks, no load or unusual resource usage (ram/cpu/io), and I have reproduced this on 2 sets of completely different machines. My initial testing was done on an openwrt router and my personal Gentoo server running in Los Angeles. Rerunning the same test (scp on and off the vpn) on my android tablet and an Ubuntu server in Irvine shows the same result.
Timeline details:
At home we switched to U-verse about a month ago. I had continued using my vpn without any issues up until Friday. Ubuntu 14.04 had just come out, so I pulled about 3gb of ISO images before heading out. The transfer completed in a reasonable amount of time. It wasn't until Saturday morning when I continued to do some work that I noticed the problem.
Luckily we have an alternative residential provider in the area, so I will be switching asap. In the meantime, I can probably work around this using obfsproxy from the tor project. I will get around to trying this tomorrow (time permitting).
