 | This article provides insufficient context for those unfamiliar with the subject.(September 2024) |
Datakit is a virtual circuit switch which was developed by Sandy Fraser at Bell Labs [1] [2] for both local-area and wide-area networks, [3] and in widespread deployment by the Regional Bell Operating Companies (RBOCs). [4]
Datakit uses a cell relay protocol similar to Asynchronous Transfer Mode. Datakit is a connection-oriented switch, with all packets for a particular call traveling through the network over the same virtual circuit. Datakit networks are still in widespread use by the major telephone companies in the United States.
Interfaces to these networks include TCP/IP and UDP, X.25, asynchronous protocols and several synchronous protocols, such as SDLC, HDLC, Bisync and others. These networks support host to terminal traffic and vice versa, host-to-host traffic, file transfers, remote login, remote printing, and remote command execution. At the physical layer, it can operate over multiple media, from slow speed EIA-232 to 500Mbit fiber optic links including 10/100 Megabit Ethernet links.
Datakit uses an adaptation protocol called Universal Receiver Protocol (URP) that spreads PDU overhead across multiple cells and performs immediate packet processing. URP assumes that cells arrive in order and may force retransmissions if not.
The Information Systems Network (ISN) was the pre-version of Datakit that was supported by the former AT&T Information Systems. The ISN was a packet switching network that was built similar to digital System 75 platform.
LAN and WAN applications with the use of what was referred to as a Concentrator that was connected via fiber optics up to 15 miles away from the main ISN. The speeds of these connections were very slow to today's standards, from 1200 to 5600 baud with most connections / end users on dumb terminals. The main support for this product came from the NCSC (National Customer Support Center) in Englewood CO then later AT&T Information Systems as the company reorganized and Bell Labs.
Most of Bell Laboratories was trunked together via Datakit networking. On top of Datakit transport service, several operating systems (including UNIX) implemented UUCP for electronic mail and dkcu for remote login. [5]
It was in production three or more years prior to the Datakit being released. Datakit was programmed similar to a Central Office with area code and seven digit location.
In 1996, AT&T spun off Bell Labs as a separate company, Lucent Technologies–who would later merge with the French firm Alcatel to become Alcatel-Lucent, before finally being acquired by Nokia in 2016. By the late 1990s, Datakit was clearly a legacy technology, being superseded by newer technologies such as IP and Ethernet. Lucent decided to discontinue their Datakit product line, but a group of former Lucent employees started a new firm, Datatek Applications, who licensed the technology from Lucent, and aimed to support the remaining Datakit users and provide gateway solutions to assist in their migration to newer technologies. [6] In part due to the continuing decline in Datakit use, Datatek Applications went out of business in January 2018.
Asynchronous Transfer Mode (ATM) is a telecommunications standard defined by the American National Standards Institute and International Telecommunication Union Telecommunication Standardization Sector for digital transmission of multiple types of traffic. ATM was developed to meet the needs of the Broadband Integrated Services Digital Network as defined in the late 1980s, and designed to integrate telecommunication networks. It can handle both traditional high-throughput data traffic and real-time, low-latency content such as telephony (voice) and video. ATM provides functionality that uses features of circuit switching and packet switching networks by using asynchronous time-division multiplexing. ATM was seen in the 1990s as a competitor to Ethernet and networks carrying IP traffic as, unlike Ethernet, it was faster and designed with quality-of-service in mind, but it fell out of favor once Ethernet reached speeds of 1 gigabits per second.
Plan 9 from Bell Labs is a distributed operating system which originated from the Computing Science Research Center (CSRC) at Bell Labs in the mid-1980s and built on UNIX concepts first developed there in the late 1960s. Since 2000, Plan 9 has been free and open-source. The final official release was in early 2015.
The 5ESS Switching System is a Class 5 telephone electronic switching system developed by Western Electric for the American Telephone and Telegraph Company (AT&T) and the Bell System in the United States. It came into service in 1982 and the last unit was produced in 2003.
A wide area network (WAN) is a telecommunications network that extends over a large geographic area. Wide area networks are often established with leased telecommunication circuits.
A network switch is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device.
Xerox Network Systems (XNS) is a computer networking protocol suite developed by Xerox within the Xerox Network Systems Architecture. It provided general purpose network communications, internetwork routing and packet delivery, and higher level functions such as a reliable stream, and remote procedure calls. XNS predated and influenced the development of the Open Systems Interconnection (OSI) networking model, and was very influential in local area networking designs during the 1980s.
UUCP is a suite of computer programs and protocols allowing remote execution of commands and transfer of files, email and netnews between computers.
A digital subscriber line access multiplexer is a network device, often located in telephone exchanges, that connects multiple customer digital subscriber line (DSL) interfaces to a high-speed digital communications channel using multiplexing techniques. Its cable internet (DOCSIS) counterpart is the cable modem termination system.
The use of Asynchronous Transfer Mode (ATM) technology and services creates the need for an adaptation layer in order to support information transfer protocols, which are not based on ATM. This adaptation layer defines how to segment higher-layer packets into cells and the reassembly of these packets. Additionally, it defines how to handle various transmission aspects in the ATM layer.
In computer networking and telecommunications, a pseudowire is an emulation of a point-to-point connection over a packet-switched network (PSN).
Internet Protocol television (IPTV), also called TV over broadband, is the service delivery of television over Internet Protocol (IP) networks. Usually sold and run by a telecom provider, it consists of broadcast live television that is streamed over the Internet (multicast) — in contrast to delivery through traditional terrestrial, satellite, and cable transmission formats — as well as video on demand services for watching or replaying content (unicast).
A terminal server connects devices with a serial port to a local area network (LAN). Products marketed as terminal servers can be very simple devices that do not offer any security functionality, such as data encryption and user authentication. The primary application scenario is to enable serial devices to access network server applications, or vice versa, where security of the data on the LAN is not generally an issue. There are also many terminal servers on the market that have highly advanced security functionality to ensure that only qualified personnel can access various servers and that any data that is transmitted across the LAN, or over the Internet, is encrypted. Usually, companies that need a terminal server with these advanced functions want to remotely control, monitor, diagnose and troubleshoot equipment over a telecommunications network.
Riverstone Networks, was a provider of networking switching hardware based in Santa Clara, California. Originally part of Cabletron Systems, and based on an early acquisition of YAGO, it was one of the many Gigabit Ethernet startups in the mid-1990s. It is now a part of Alcatel-Lucent and its operations are being wound down via a Chapter 11 filing by their current owners.
In computer networking, DECserver initially referred to a highly successful family of asynchronous console server / terminal server / print server products introduced by Digital Equipment Corporation (DEC) and later referred to a class of UNIX-variant application and file server products based upon the MIPS processor. In February 1998, DEC sold its Network Products Business to Cabletron, which then spun out as its own company, Digital Networks, in September 2000.
A computer network is a set of computers sharing resources located on or provided by network nodes. Computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.
In audio and broadcast engineering, audio over Ethernet (AoE) is the use of an Ethernet-based network to distribute real-time digital audio. AoE replaces bulky snake cables or audio-specific installed low-voltage wiring with standard network structured cabling in a facility. AoE provides a reliable backbone for any audio application, such as for large-scale sound reinforcement in stadiums, airports and convention centers, multiple studios or stages.
Alcatel–Lucent S.A. was a multinational telecommunications equipment company, headquartered in Boulogne-Billancourt, Paris France. It was formed in 2006 by the merger of France-based Alcatel SA and U.S.-based Lucent Technologies, the latter being a successor of AT&T's Western Electric and a holding company of Bell Labs.
The following is a comparison of audio over Ethernet and audio over IP audio network protocols and systems.