> Fred Baker wrote: > But frankly, every sample I have seen in the past decade placed > SMTP in the "noise" category, a single digit percentage or less. There might be a handful of exceptions (people in the middle of nowhere with a dial-up worth of bandwidth and/or relying exclusively on pricey satlink with a currency not worth anything, etc) but elsewhere this is what I hear too. > Estimates I have heard from ISPs and seen on measurement sites > available to me have consistently placed HTTP/HTTPS at better > than 2/3 of total traffic in the late 1990's, and in the past > few years have either estimated HTTP/HTTPS as neck-and-neck > with file sharing traffic or have put file sharing well ahead. You forgot FTP, but I also concur. The reason I am following on this the part of file sharing traffic: a recent entry in the list of "big" p2p protocols is BitTorrent. Figures of some 30% of the total Internet bandwidth being used by BT were discussed recently. Read ahead. Contrary to the other big ones (eDonkey(eMule), DirectConnect(Kaaza), WinMX(WinMX), Gnutella(Shareaza)), BT has been underestimated by many people (beginning with me :-). It's not as easy as classify traffic as it used to be. BitTorrent is becoming _the_ choice of hardcore file swappers with a darn good reason: download speed is basically unlimited. I did not believe until I actually installed it at home, and short of a good distributed probe not available yet, here it is on a $37/mo residential 3mbit down / 384kbit up aDSL: http://home.pacbell.net/arn-py/photos/bt_bandwidth.jpg Fast enough? (this requires downloading from anything between 50 and 100 peers simultaneously). However, to get this kind of speed there's a catch, and this catch is called private trackers and private torrents. Generic torrent sites such as suprnova are not too shabby, but can't compare in terms of speed with private trackers (a generic torrent will rarely yield more than 50kByte/s). Basically, what we have failed to see coming is a large and growing number of private tracker sites (a lot being based on ByteMonsoon) that both a) require a custom port number and b) enforce UL/DL ratios. What's annoying with these: a) custom port numbers (read rationale below) Before, life was simple: Direct Connect 411 - 413 Kazaa 1214 eDonkey 4662 Gnutella 6346 - 6347 WinMX 6699 (with some minor and obvious variations, such as 5662 for some eDonkey variants) Now, you can forget about port-based measuring. Even though BitTorrent is supposedly 6881 - 6889, most private trackers have something like this clearly stated: > Why do I get a "rejected by tracker - Port xxxx is blacklisted" error? > Your client is reporting to the tracker that it uses one of the default > bittorrent ports (6881-6889) or any other common p2p port for incoming > connections. > joeblow's tracker (name altered to protect the guilty) does not allow > clients to use ports commonly associated with p2p protocols. The reason > for this is that it is a common practice for ISPs to throttle those > ports (that is, limit the bandwidth, hence the speed). > The blocked ports list include, but is not necessarily limited to, the > following: Direct Connect 411 - 413 Kazaa 1214 eDonkey 4662 Gnutella > 6346 - 6347 BitTorrent 6881 - 6889 > In order to use use our tracker you must configure your client to use > any port range that does not contain those ports (a range within the > region 49152 through 65535 is preferable, cf. IANA). Notice that some > clients, like Azureus 2.0.7.0 or higher, use a single port for all > torrents, while most others use one port per open torrent. The size > of the range you choose should take this into account (typically less > than 10 ports wide. There is no benefit whatsoever in choosing a wide > range, and there are possible security implications). > These ports are used for connections between peers, not client to > tracker. Therefore this change will not interfere with your ability > to use other trackers (in fact it should increase your speed with > torrents from any tracker, not just ours). Your client will also still > be able to connect to peers that are using the standard ports. If your > client does not allow custom ports to be used, you will have to switch > to one that does. > Do not ask us, or in the forums, which ports you should choose. The > more random the choice is the harder it will be for ISPs to catch on > to us and start limiting speeds on the ports we use. If we simply > define another range ISPs will start throttling that range also. > Finally, remember to forward the chosen ports in your router and/or > open them in your firewall, should you have them. See the Why am I > listed as not connectable? section and links therein for more > information on this. In short: as of today, forget port-based stats. As of tomorrow, tough luck with stats at all as the traffic not only being on a random port will also be encrypted so you can't inspect the contents of the packet. b) ratios: > Download Ratios Policies > With a download between: > 5.0 GB and 7.5 GB you must have a ratio of at least 0.2 > 7.5 GB and 10 GB you must have a ratio of at least 0.3 > Above 10 GB you must have a ratio of at least 0.4 > Just remember: Who ever you are, What ever your status is, > How many millions you did donate .. IF YOUR RATIO DROPS > BELOW 0.4 (w/10gigs or more d/l'ed) AND WE SEE NO ACTIVITY > FROM YOU TO GET IT UP OR IF YOU THINK YOU HAVE A RIGHT TO > INSULT PEOPLE OR THIS SITE IN GENERAL.. WE WILL BAN YOU!!*** In short: you can download at 300kBytes per second, _IF_ you leave your machine open so your buddies can download too. Simple mathematics: this is unicast traffic so if you don't maintain a 1/1 overall ratio the system does not work. Corollary: if your upstream is 10 times slower than your downstream you need to leave your upstream open 10 times as long as you download. This is where it kills: non-hardcore file swappers that would otherwise open their P2P clients only occasionally now leave them on 24/7 to pump up their UL/DL ratio: "I maintain my ratio above 2.0 at all times, so no problem if I decide to download that 55 GigaByte double-layer DVD StarWars 6-episode set plus collateral material over the weekend". <proverb> Small torrents make big rivers. </proverb> Welcome to file sharing. Michel. _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf
