File Service Protocol
Encyclopedia
File Service Protocol is a UDP
-based replacement for the File Transfer Protocol
, designed for anonymous access with lower hardware and network requirements than FTP. In particular, because it uses UDP, it avoids the problems that many FTP servers have had with requiring a separate process for each client, and because it is built to use an unreliable protocol, it can more easily handle resuming a transfer after a network failure.
and id Software
provided FSP service in addition to FTP for some time), but became very popular in the early-to-mid-1990s for underground sites containing pornography
and/or warez
. Because an FSP server only requires one process (as opposed to one process per client for most FTP servers), it is much harder for a system administrator
to notice it in a process list; also, since it uses UDP, it is less likely to be noticed by a network administrator
.
Eventually, however, an increased use of firewalls, a decreasing usage of the shell account
s required to run a server or most of the clients, and a lack of FSP support in web browser
s caused its use to taper off, and the warez scene moved to HTTP and FXP
while pornography moved to publicly-advertised web server
s.
, it has no official port number. However, as a UDP equivalent of FTP, official FSP servers frequently run on UDP port 21, which is the same as FTP's TCP port number. Because FSP uses UDP and FTP uses TCP they can both run at same time on same port number without conflict. Unofficial servers may run on any port, although 2121 was a popular choice. (On most *nix systems, only the root user can start a process that listens on a port under 1024.)
User Datagram Protocol
The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
-based replacement for the File Transfer Protocol
File Transfer Protocol
File Transfer Protocol is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server...
, designed for anonymous access with lower hardware and network requirements than FTP. In particular, because it uses UDP, it avoids the problems that many FTP servers have had with requiring a separate process for each client, and because it is built to use an unreliable protocol, it can more easily handle resuming a transfer after a network failure.
History
FSP never reached the popularity of FTP for legitimate use (although wuarchiveWU-FTPD
WU-FTPD is a free FTP server software for Unix-like operating systems.It was originally written by Chris Myers and Bryan D...
and id Software
Id Software
Id Software is an American video game development company with its headquarters in Richardson, Texas. The company was founded in 1991 by four members of the computer company Softdisk: programmers John Carmack and John Romero, game designer Tom Hall, and artist Adrian Carmack...
provided FSP service in addition to FTP for some time), but became very popular in the early-to-mid-1990s for underground sites containing pornography
Pornography
Pornography or porn is the explicit portrayal of sexual subject matter for the purposes of sexual arousal and erotic satisfaction.Pornography may use any of a variety of media, ranging from books, magazines, postcards, photos, sculpture, drawing, painting, animation, sound recording, film, video,...
and/or warez
Warez
Warez refers primarily to copyrighted works distributed without fees or royalties, and may be traded, in general violation of copyright law. The term generally refers to unauthorized releases by organized groups, as opposed to file sharing between friends or large groups of people with similar...
. Because an FSP server only requires one process (as opposed to one process per client for most FTP servers), it is much harder for a system administrator
System administrator
A system administrator, IT systems administrator, systems administrator, or sysadmin is a person employed to maintain and operate a computer system and/or network...
to notice it in a process list; also, since it uses UDP, it is less likely to be noticed by a network administrator
Network administrator
A network administrator, network analyst or network engineer is a person responsible for the maintenance of computer hardware and software that comprises a computer network...
.
Eventually, however, an increased use of firewalls, a decreasing usage of the shell account
Shell account
A shell account is a user account on a remote server which gives access to a shell via a command-line interface protocol such as telnet or ssh....
s required to run a server or most of the clients, and a lack of FSP support in web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
s caused its use to taper off, and the warez scene moved to HTTP and FXP
File eXchange Protocol
File eXchange Protocol and is a method of data transfer which uses FTP to transfer data from one remote server to another without routing this data through the client's connection. Conventional FTP involves a single server and a single client; all data transmission is done between these two...
while pornography moved to publicly-advertised web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
s.
Port number
As the FSP protocol is not officially recognized by IANAInternet Assigned Numbers Authority
The Internet Assigned Numbers Authority is the entity that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System , media types, and other Internet Protocol-related symbols and numbers...
, it has no official port number. However, as a UDP equivalent of FTP, official FSP servers frequently run on UDP port 21, which is the same as FTP's TCP port number. Because FSP uses UDP and FTP uses TCP they can both run at same time on same port number without conflict. Unofficial servers may run on any port, although 2121 was a popular choice. (On most *nix systems, only the root user can start a process that listens on a port under 1024.)