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Ask Slashdot: How To Diagnose Traffic Throttling and Work Around It?
Aguazul2 writes "I live in Peru and use OpenVPN to connect to my own Linux VPS in the UK for non-live TV. Recently the VPN connection has slowed to a crawl (5% previous rate). Further investigation shows that all connections to my VPS from Peru (even HTTP) are equally slow, whilst the rest of the 'net seems fine. My VPS host says they do no traffic shaping, and connections from Germany to the VPS are fast. This leaves the NSA and Telefonica (Movistar) as suspects. Could the NSA be slowing all VPNs to/from South America because of Snowden and Greenwald? A traceroute shows traffic going through domains with NYC in their name — are my packets being indefinitely detained in transit? Or maybe it is Telefonica and their Sandvine traffic management? Either way this certainly isn't network neutrality, especially on an 'unlimited' plan. Is there a way to tell for certain who is throttling me? If Telefonica have throttled traffic to/from that one IP address, what options do I have to work around it? It seems that separate connections are throttled independently, so can I multiplex over many UDP ports without having to hack OpenVPN myself? This is really frustrating, especially with two untrustworthy parties on the route. I wonder, is this kind of mess the future of the internet?"
I've had a client I provide consulting for suggest that their poor connectivity is also in some way due to the NSA. People need to understand that it is paramount to the NSA that they are covert. They do not need to do real-time processing of the data: that is only necessary for filtering. It suffices for them to simply capture raw data for later analysis or decryption as necessary. Of course capturing data does not result in any slowdown or other noticeable effects. It does not make any sense whatsoever for the NSA to be slowing or otherwise blocking connectivity, as that is counterproductive to the acquisition of intelligence data.
It's just amusing to me to see NSA as the scapegoat of the day for any quirk anyone experiences related to computers or connectivity in general.
Better known as 318230.
Years ago I worked on a broadband remote access server and one requirement we got was to support lawful traffic interception. Basically all law enforcement wanted was a copy of all of the packets. Packets are not slowed down or stopped by this process.
In my case the hardware was just not capable of doing what was needed but there was plenty of off the shelf hardware that could be installed in the network to provide the filtering and packet mirroring needed.
It is possible that one of the VPN's upstream providers is running into congestion. One of the best ways I have found is to use traceroute. At one time I was getting unusable Internet connectivity through AT&T after they acquired my local cable modem network from @Home. It took them many months to discover that throttling all aggregate upstream traffic to 128Kbps is a bad idea. As much as people bitch and moan about Comcast, it is lightyears better than anything I got through AT&T. In this case, traceroute clearly showed where packets were getting delayed and dropped, which was one of the routers inside AT&T.
Unfortunately, for a VPN this is much more difficult since the Internet hops are hidden via the tunnel.
There are many different ways to tunnel traffic. If the tunnel is Microsoft's PPTP protocol then it's not very secure. If on the other hand it is using IPSec then it should be a lot more secure. There are also other tunneling protocols that do not specify any encryption, i.e. MPLS.
This post is encrypted twice with ROT-13. Documenting or attempting to crack this encryption is illegal.
My office Internet connection recently went from about 30Mbps down to 1.5Mbps, then back to 50Mbps a month later. No explanation, and speed tests to our ISP all came through at full speeds. We only saw problems on routes going outside our city and headed west. There were also a few inaccessible sites, but those were in very specific local areas. Ultimately, the best guess anyone could come up with is that a network to the west of our city had some routing problems.
We weren't the only customers to complain about a slowdown, but our ISP couldn't really do much about it. The Internet is made up of many networks working together, and sometimes shit happens. I wouldn't jump so quickly to assume it's non-neutral throttling or the NSA, when it could just be a careless guy with a badly-aimed backhoe. Give it some time, see if it improves, and if not, it may be time to move your VPS.
As an aside, you're likely going through New York because that's how you're reaching Europe to get to your UK-based VPS. Many transatlantic cables end in New York City, mostly because the stock market pays dearly for the few nanoseconds of lower latency.
You do not have a moral or legal right to do absolutely anything you want.
If you are a US ISP, it is required that you have monitoring in place. If you don't want to hamper your entire infrastructure while doing so, you get a bunch of taps and install them all over your network. One very good provider for this is Gigamon. Taps do not add any latency in your traffic. They are completely invisible to all other network devices. Traffic shaping (throttling) is done by the source typically but can be done at the destination ISP. Basically, your connection is assigned a Package in the Shaper. The packages determine how fast each classification groups of traffic are allowed to go. Classifications are determined by whoever manages the shaper for that ISP. Shapers can also dynamically change the speed you are allowed to have for a classification group based on bandwidth used, time used, and volume of traffic.
If you are not throttled from Germany to your home but are from Peru to your home, chances are you are throttled from your ISP in Peru. It is typical for transits to cross borders, so your traffic going through NYC is normal. BGP (the routing protocol of the internet) determined that to be the best path. This is mostly managed, but is still fairly dynamically determined by the routing protocol.
Course of action: Switch ISPs, get a new IP address (if they are not very good at configuring a shaper this will work, otherwise not), try a proxy, stop using it for a day or more and it will go away (temporarily most likely). This is done dynamically in the shaper. There is not some dude with his finger on a 'throttle' button. Everything is automatic. Just figure out the how their throttling deterministic state diagram works and you can avoid throttling. Most likely they are throttling you because of your volume of use. It costs a lot for transit access and you are using more than most others by streaming through a vpn.
Who gave a slashdot account to that computer trained to tell jokes?
That may have been their theory, or it may have been they wondered if US gov was intentionally slowing VPN connections from that part of the world.
If the theory was that capturing data would slow it down, the answer is "no". For that, you'd use port mirroring. Where a switch or router would normally take data in on one line and output it on another, you set it to accept data on the one line and output it on TWO others simultaneously. The data still flows at the same speed. It just flows to two locations separately - the intended recipient and the government.
Didn't you know? Slashdot is a large Turing Test system. Most of the participants are AIs.
Interestingly, the most promising test results are with the "First Post" trolls. Apparently nobody can imagine that an AI could be that stupid.
The Tao of math: The numbers you can count are not the real numbers.