Julien Danjou and others replied to my "please don't obfuscate BitTorrent" post, pointing out providers in {France, Canada} that already filter BitTorrent one way or another. I've read similar things about some DSL providers in Germany (Telekom however is proud that they don't do that).

But basically this only shows my point: by having the major p2p filesharing protocols use non-standard ports and non-detectable protocols, more and more providers take measures like doing QoS for non-standard ports or filtering them altogether. And just as you reported, this has bad side effects on the ability of other users to e.g. use VoIP or play online games.

Remember: my point is to make P2P protocols easy to filter/limit by routers, so provider do NOT block/throttle all non-HTTP connections, but can selectively throttle only P2P filesharing when they think they need to. Because otherwise they'll break other stuff such as online games and VoIP.

Now by putting your BitTorrent on ports such as 80 or some VoIP port which isn't throttled, you only cause these providers to e.g. install a transparent proxy for these services. You make it only worse.

I agree that you don't have that much choice in countries where there is some kind of monopoly there. But then this increase in filtering will probably allow new companies to enter the market.

I redecorated my (physical) desktop today. I still need some more posters, too much empty wall. But it's nice to lean back and have some colorful stuff to look at.

But do you know what's best?

My laptop is back from repair. I have backlight again! Though I think they used a too short light tube, it feels somewhat darker on the left and right. But the laptop is old anyway. And the old tubes used to have a reddish tint there...

I love having my 15" 1600x1200 screen back. ;-)

Recently there was a discussion on whether BitTorrent should get some encryption (or obfuscation, more likely) added.

Right now, you can filter out BitTorrent traffic with the following iptables command (note: this needs iptables 1.3.4 and a recent kernel):

iptables -I OUTPUT -j DROP -m string --string "BitTorrent protocol" --algo bm --from 0 --to 100

The nice thing is, that this match is very unlikely to match non-Bittorrent traffic. Linux users can use it to filter out all BitTorrent traffic or mark it for speed restrictions.

Network operators are very interested in filtering this traffic: it slows down more important traffic (and if you are e.g. using stochastic fair queing, the large number of connections for P2P filesharing will make it get a larger share than other apps!) and can cause costs.

If you have mobile users, who e.g. connect their laptop to your network, they will occasionally use BitTorrent at home, and forget to disable it when they connect to your network. That's really bad, it happens and it's not like this is intentional "malbehaviour" or "sabotage"!

So back to the original topic - obfuscating BitTorrent traffic. Let me explain what network operators might do when BitTorrent can't be slowed or filtered any more (Note that this already applies to some services such as Skype or Kazaa as far as I know):

First of all, they might decide to filter all connections to non-standard ports. This effectively eliminates (most of) filesharing - but also e.g. Skype and some IM and chat services. Basically any non-standard service. (Note that "professional" VoIP services using SIP may still be whitelisted).

Secondly, they could decide to slow down all connections to non-standard ports. This would make filesharing, Skype, IM etc. still possible, but for example file transfers via IM will be really slow. No video via Skype, probably, depending on the limits set in traffic shaping.

Thirdly, they could disable all outgoing connections and require you to use proxies for that. Then you need to enable/disable your proxy all the time when switching networks, and you'll only be able to use a limited set of services. Again, Telephony via SIP is still technically possible, using a SIP proxy or by whitelisteing major SIP providers. Skype is no longer possible. IM needs whitelisting, and will likely be blocked, too.

None of these options are very favourable for the users. So please do not support "obfuscated" Protocols such as Kazaa or Skype, or an obfuscated variant of BitTorrent. Stick with stuff administrators can set up policies for - and be nice to your admins. Tunneling via non-standard ports, hiding services will only get you into trouble, and probably even make innocent other users suffer.

After all, filesharing - especially illegal downloading movies and music - is not THAT important, is it? So please make the important services not suffer from it. Thank you.

Oh, and please use SIP, not Skype. Because your admin can whitelist your SIP provider if you tell him you need it for work or setup a proxy for that - and with Skype, he might be afraid that you become a supernode and cause high traffic costs. And then there is a much larger software choice for SIP, including many OpenSource solutions, including PBX software such as Asterisk.

GMail hat inzwischen den lange vermissten "Delete"-Knopf, und jetzt wurde anscheinend auch Google Talk mit GMail integriert...

Beides geht derzeit aber nur, wenn man in GMail als Sprache "English (US)" einstellt. Der "Delete"-Knopf war mir aber schon immer wichtig...