The UDP tracker

protocol Protocol may refer to: Sociology and politics * Protocol (politics), a formal agreement between nation states * Protocol (diplomacy), the etiquette of diplomacy and affairs of state * Etiquette, a code of personal behavior Science and technology ...

is a high-performance low-overhead

BitTorrent tracker A BitTorrent tracker is a special type of server that assists in the communication between peers using the BitTorrent protocol. In peer-to-peer file sharing, a software client on an end-user PC requests a file, and portions of the requested fil ...

protocol. It uses the stateless

User Datagram Protocol In computer networking, the User Datagram Protocol (UDP) is one of the core communication protocols of the Internet protocol suite used to send messages (transported as datagrams in packets) to other hosts on an Internet Protocol (IP) network. ...

(UDP) for data transmission instead of the HTTP protocol (over TCP) regular trackers use. The data is in a custom binary format instead of the standard

bencode Bencode (pronounced like ''Bee-encode'') is the encoding used by the peer-to-peer file sharing system BitTorrent for storing and transmitting loosely structured data. It supports four different types of values: * byte strings, * integers, * list ...

algorithm BitTorrent uses for most communication.

URL A Uniform Resource Locator (URL), colloquially termed as a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifie ...

s for this protocol have the following format: .

Comparison with the HTTP tracker

The UDP tracker is better optimized and puts less strain on the tracking server. Neither tracker has any effect on transfer speeds.

Clients implementing the protocol

BitComet BitComet (originally named SimpleBT client from versions 0.11 to 0.37) is a cross-protocol BitTorrent, HTTP and FTP client written in C++ for Microsoft Windows and available in 52 different languages. Its first public release was version 0.28. Th ...

BitLord BitLord is a proprietary adware BitTorrent client available for Microsoft Windows, macOS and Android. It is advertised as, and largely reviewed as, one of the easiest BitTorrent applications to use. With a built-in search engine, video player w ...

*BitRocket *BitSpirit *

Deluge A deluge is a large downpour of rain, often a flood. The Deluge refers to the flood narrative in the Biblical book of Genesis. Deluge may also refer to: History *Deluge (history), the Swedish and Russian invasion of the Polish-Lithuanian Comm ...

FlashGet FlashGet (formerly JetCar, from the literal translation of the Chinese phrase ) was a freeware download manager for Microsoft Windows. It was originally available in either paid or ad-supported versions, the latter of which included an Interne ...

KTorrent KTorrent is a BitTorrent client that is part of the KDE Gear. Features KTorrent is often received as a client intended to be feature rich. Features include: *Upload and download speed capping / throttling & scheduling *Internet searching with ...

*libbt *

Libtorrent (Rasterbar) libtorrent is an open-source software, open-source implementation of the BitTorrent protocol. It is written in and has its main library interface in C++. Its most notable features are support for Mainline DHT, IPv6, HTTP seeds and μTorrent's ...

qBittorrent qBittorrent is a cross-platform free and open-source BitTorrent client written in native application, native C++. It relies on Boost (C++ libraries), Boost, Qt (software), Qt 6 toolkit and the libtorrent-rasterbar library (for the torrent back-e ...

rtorrent rTorrent is a text-based BitTorrent client written in C++, based on the ncurses and libTorrent (not to be confused with libtorrent) libraries for Unix, whose author's goal is "a focus on high performance and good code". Technical detail ...

(implementing

libTorrent (Rakshasa) rTorrent is a text-based BitTorrent client written in C++, based on the ncurses and libTorrent (not to be confused with libtorrent) libraries for Unix, whose author's goal is "a focus on high performance and good code". Technical details ...

) *

μTorrent μTorrent, or uTorrent (see pronunciation) is a proprietary adware BitTorrent client owned and developed by Rainberry, Inc. with over 150 million users. It is the most widely used BitTorrent client outside China; globally only behind Xunlei. Th ...

*Turbo Torrent *

Vuze Vuze (previously Azureus) is a BitTorrent client used to transfer files via the BitTorrent protocol. Vuze is written in Java, and uses the Azureus Engine. In addition to downloading data linked to .torrent files, Azureus allows users to view, p ...

*XBT Client *

MLDonkey MLDonkey is an open-source software, open-source, multi-protocol, peer-to-peer file sharing application that runs as a Front and back ends, back-end server application on many platforms. It can be controlled through a user interface provided by one ...

Transmission Transmission may refer to: Medicine, science and technology * Power transmission ** Electric power transmission ** Propulsion transmission, technology allowing controlled application of power *** Automatic transmission *** Manual transmission *** ...

Tixati Tixati is a proprietary Linux and Windows BitTorrent client written in C++. It has standalone and portable versions with each new client version. Features In addition to standard BitTorrent client-sharing functions, Tixati provides integral ...

Criticisms

* Limited

IPv6 Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic ...

support (the protocol specifies a 32-bit integer for the IP address and supports pseudo-headers for 128-bit IPv6 addresses) * No mechanism for

index Index (or its plural form indices) may refer to: Arts, entertainment, and media Fictional entities * Index (''A Certain Magical Index''), a character in the light novel series ''A Certain Magical Index'' * The Index, an item on a Halo megastru ...

sites to scrape an entire tracker ** This can be supported by traditional TCP scrape mechanisms, as it's not a performance issue. * No mechanism for trackers to enforce client restrictions * The UDP tracker protocol has no field to represent the user agent, as the HTTP protocol has. However, the convention to encode the user agent and version inside the peer_id field still applies. * No mechanism for trackers to send warning messages * No compression, especially problematic for large announce responses.

References

External links

UDP tracker protocol specification

an UDP torrent tracker list
BitTorrent {{Internet-stub