Zephyr (protocol)
Encyclopedia
Created at MIT
, as part of Project Athena
, Zephyr was designed as an instant messaging
protocol and application-suite with a heavy Unix
background. Using the "do one thing, do it well" philosophy
of Unix, it was made up of several separate programs working together to make a complete messaging system. Zephyr and IRC
are the first widely used IP
-based instant-messaging systems.
and a Visiting Research Scientist at Project Athena
. The design originated as a solution to the "reverse Remote Procedure Call
(RPC)" problem: how can service providers (servers in a client–server system) locate and communicate with service users. The initial concept emerged from conversations between Ciarán and Michael R. Gretzinger, another systems engineer at Project Athena
, in early 1986. By mid to late 1986 Ciarán had distilled the problem to two specific issues: the ability to locate users in a distributed computing environment (known today as "presence detection"), and the ability to deliver scalable, light-weight, and authentic messages in a distributed computing environment. The Zephyr Development Team (Mark W. Eichin, Robert S. French, David C. Jedlinsky, John T. Kohl, William E. Sommerfeld) was responsible for the creation of the initial code-base and the subsequent releases that were issued throughout the late 1980s.
environments such as Carnegie Mellon
, Iowa State, University of Maryland, College Park
, Brown University
and MIT. It has been largely replaced by modern and more popular instant messenger systems such as XMPP
. MIT currently operates both Zephyr and XMPP
.
datagrams sent between ports 2102, 2103, and 2104. It is incompatible with most routers doing NAT
because it reports the internal IP address and so returning datagrams are incorrectly routed. Most sites have deployed Zephyr using Kerberos 4
authentication exclusively, though in late 2007, some sites, including Iowa State, deployed Zephyr using Kerberos 5
.
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
, as part of Project Athena
Project Athena
Project Athena was a joint project of MIT, Digital Equipment Corporation, and IBM to produce a campus-wide distributed computing environment for educational use. It was launched in 1983, and research and development ran until June 30, 1991, eight years after it began...
, Zephyr was designed as an instant messaging
Instant messaging
Instant Messaging is a form of real-time direct text-based chatting communication in push mode between two or more people using personal computers or other devices, along with shared clients. The user's text is conveyed over a network, such as the Internet...
protocol and application-suite with a heavy Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
background. Using the "do one thing, do it well" philosophy
Unix philosophy
The Unix philosophy is a set of cultural norms and philosophical approaches to developing software based on the experience of leading developers of the Unix operating system.-McIlroy: A Quarter Century of Unix:...
of Unix, it was made up of several separate programs working together to make a complete messaging system. Zephyr and IRC
Internet Relay Chat
Internet Relay Chat is a protocol for real-time Internet text messaging or synchronous conferencing. It is mainly designed for group communication in discussion forums, called channels, but also allows one-to-one communication via private message as well as chat and data transfer, including file...
are the first widely used IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
-based instant-messaging systems.
Creation
Zephyr is the invention of Ciarán Anthony DellaFera who was, at that time, an employee of Digital Equipment CorporationDigital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
and a Visiting Research Scientist at Project Athena
Project Athena
Project Athena was a joint project of MIT, Digital Equipment Corporation, and IBM to produce a campus-wide distributed computing environment for educational use. It was launched in 1983, and research and development ran until June 30, 1991, eight years after it began...
. The design originated as a solution to the "reverse Remote Procedure Call
Remote procedure call
In computer science, a remote procedure call is an inter-process communication that allows a computer program to cause a subroutine or procedure to execute in another address space without the programmer explicitly coding the details for this remote interaction...
(RPC)" problem: how can service providers (servers in a client–server system) locate and communicate with service users. The initial concept emerged from conversations between Ciarán and Michael R. Gretzinger, another systems engineer at Project Athena
Project Athena
Project Athena was a joint project of MIT, Digital Equipment Corporation, and IBM to produce a campus-wide distributed computing environment for educational use. It was launched in 1983, and research and development ran until June 30, 1991, eight years after it began...
, in early 1986. By mid to late 1986 Ciarán had distilled the problem to two specific issues: the ability to locate users in a distributed computing environment (known today as "presence detection"), and the ability to deliver scalable, light-weight, and authentic messages in a distributed computing environment. The Zephyr Development Team (Mark W. Eichin, Robert S. French, David C. Jedlinsky, John T. Kohl, William E. Sommerfeld) was responsible for the creation of the initial code-base and the subsequent releases that were issued throughout the late 1980s.
Application
Zephyr is still in use today at a few universityUniversity
A university is an institution of higher education and research, which grants academic degrees in a variety of subjects. A university is an organisation that provides both undergraduate education and postgraduate education...
environments such as Carnegie Mellon
Carnegie Mellon University
Carnegie Mellon University is a private research university in Pittsburgh, Pennsylvania, United States....
, Iowa State, University of Maryland, College Park
University of Maryland, College Park
The University of Maryland, College Park is a top-ranked public research university located in the city of College Park in Prince George's County, Maryland, just outside Washington, D.C...
, Brown University
Brown University
Brown University is a private, Ivy League university located in Providence, Rhode Island, United States. Founded in 1764 prior to American independence from the British Empire as the College in the English Colony of Rhode Island and Providence Plantations early in the reign of King George III ,...
and MIT. It has been largely replaced by modern and more popular instant messenger systems such as XMPP
Extensible Messaging and Presence Protocol
Extensible Messaging and Presence Protocol is an open-standard communications protocol for message-oriented middleware based on XML . The protocol was originally named Jabber, and was developed by the Jabber open-source community in 1999 for near-real-time, extensible instant messaging , presence...
. MIT currently operates both Zephyr and XMPP
Extensible Messaging and Presence Protocol
Extensible Messaging and Presence Protocol is an open-standard communications protocol for message-oriented middleware based on XML . The protocol was originally named Jabber, and was developed by the Jabber open-source community in 1999 for near-real-time, extensible instant messaging , presence...
.
Points of interest
Zephyr uses UDPUser 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...
datagrams sent between ports 2102, 2103, and 2104. It is incompatible with most routers doing NAT
Network address translation
In computer networking, network address translation is the process of modifying IP address information in IP packet headers while in transit across a traffic routing device....
because it reports the internal IP address and so returning datagrams are incorrectly routed. Most sites have deployed Zephyr using Kerberos 4
Kerberos protocol
Kerberos is a computer network authentication protocol which works on the basis of "tickets" to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner. Its designers aimed primarily at a client–server model, and it provides mutual...
authentication exclusively, though in late 2007, some sites, including Iowa State, deployed Zephyr using Kerberos 5
Kerberos protocol
Kerberos is a computer network authentication protocol which works on the basis of "tickets" to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner. Its designers aimed primarily at a client–server model, and it provides mutual...
.
Client Support
- Multi-protocol IM client BarnOwl has always had Zephyr protocol support.
- Multi-protocol IM client PidginPidgin (software)Pidgin is an open-source multi-platform instant messaging client, based on a library named libpurple. Libpurple has support for many commonly used instant messaging protocols, allowing the user to log into various services from one application.The number of Pidgin users was estimated to be over 3...
supports the Zephyr protocol since version 0.11.0-pre10 (April 13, 2001). - Multi-protocol IM client AdiumAdiumAdium is a free and open source instant messaging client for Mac OS X that supports multiple IM networks, including Windows Live Messenger, Yahoo! Messenger, Google Talk, AIM, ICQ, and XMPP. It supports many protocols through the libraries libezv , MGTwitterEngine , and libpurple...
added support for Zephyr in Version 0.70 (October 18, 2004) and dropped support in version 1.4b6 (June 3, 2009).
See also
- Comparison of instant messaging clientsComparison of instant messaging clientsThe following tables compare general and technical information for a number of instant messaging clients. Please see the individual products' articles for further information. This article is not all-inclusive or necessarily up-to-date...
- Gale, the Caltech equivalent of the Zephyr protocol
External links
- Zephyr 3.0
- The 1988 Usenix paper on Zephyr
- Zephyr on Athena
- MIT Q&A about Zephyr
- [ftp://athena-dist.mit.edu/pub/ATHENA/zephyr/ Zephyr's Source Code]