Tymnet
Encyclopedia
Tymnet was an international data communications network headquartered in San Jose
, California
that used virtual call packet switched technology and X.25
, SNA
/SDLC
, ASCII
and BSC
interfaces to connect host computers (servers) at thousands of large companies, educational institutions, and government agencies. Users typically connected via dial-up connections or dedicated async connections. The business consisted of a large public network that supported dial-up users and a private network business that allowed government agencies and large companies (mostly banks and airlines) to build their own dedicated networks. The private networks were often connected via gateways to the public network to reach locations not on the private network. Tymnet was also connected to dozens of other public networks in the United States
and internationally via X.25/X.75
gateways.
As the Internet
grew and became almost universally accessible in the late 1990s, the need for services such as Tymnet migrated to the Internet style connections, but still had some value in the third world
and for specific legacy roles. However the value of these links continued to decrease, and Tymnet was officially shut down in 2004.
access in most cities in the United States and to a limited degree in Canada
, which preferred its own DATAPAC
service.
Users would dial into Tymnet and then interact with a simple command-line interface to establish a connection with a remote system. Once connected, data was passed to and from the user as if connected directly to a modem on the distant system. For various technical reasons, the connection was not entirely "invisible", and sometimes required the user to enter arcane commands to make 8-bit clean connections work properly for file transfer.
Tymnet was extensively used by large companies to provide dial-up services for their employees who were "on the road", as well as a gateway for users to connect to large online services such as CompuServe
or The Source
.
layout which allowed the supervisors to be aware of every possible end-point. In its original incarnation, the users connected to nodes built using Varian
minicomputers, then entered commands that were passed to the supervisor which ran on a XDS 940
host.
Circuits were character oriented and the network was oriented towards interactive character-by-character full-duplex
communications circuits. The nodes handled character translation between various character sets, which were numerous at that point in time. This did have the side effect of making data transfers quite difficult, as byte
s from the file would be invisibly "translated" without specific intervention on the part of the user.
Tymnet later developed their own custom hardware, the Tymnet Engine, which contained both nodes and a supervisor running on one of those nodes. As the network grew, the supervisor was in danger of being overloaded by the sheer number of nodes in the network, since the requirements for controlling the network took a great part of the supervisor's capacity.
Tymnet II was developed in response to this challenge. Tymnet II was developed to ameliorate the problems outlined above by off-loading some of the work-load from the supervisor and providing greater flexibility in the network by putting more intelligence into the node code. A Tymnet II node would set up its own "permuter tables", eliminating the need for the supervisor to keep copies of them, and had greater flexibility in handling its inter-node links. Data transfers were also possible via "auxiliary circuits".
was founded in 1964 as a time sharing company, selling computer time and software packages for users. It had two SDS/XDS
940 computers; access was via direct dial-up to the computers. In 1968, it purchased Dial Data, another time-sharing service bureau.
In 1968, Norm Hardy and LaRoy Tymes developed the idea of using remote sites with minicomputers to communicate with the mainframes. The minicomputers would serve as the network's nodes, running a program called a "supervisor" to route data. In November 1971, the first Tymnet Supervisor program became operational. Written in assembly code by LaRoy Tymes for the SDS 940, with architectural design contributions from Norman Hardy, the "Supervisor" was the beginning of the Tymnet network. The Varian
620i (8K of 16 bit words) was used for the TYMNET nodes. Initially, Tymshare and its direct customers were the network's only users. In February, 1972, the National Library of Medicine became the first non-Tymshare network customer with a toxicology data base on an IBM 360.
It soon became apparent that the SDS 940 could not keep up with the rapid growth of the network. In 1972, Joseph Rinde joined the Tymnet group and began porting the Supervisor code to the 32-bit Interdata 7/32
, as the 8/32 was not yet ready. In 1973, the 8/32 became available, but the performance was disappointing and a crash-effort was made to develop a machine that could run Rinde's Supervisor.
In 1974, a second, more efficient version of the Supervisor software became operational. The new Tymnet "Engine" software was used on both the Supervisor machines and on the nodes.
After the migration to the Tymnet Engine, they started developing Tymnet accounting and other support software on the PDP-10
. Tymshare sold the Tymnet network software to TRW
, who created their own private network, TRWNET.
Tymes and Rinde then developed "Tymnet II". Tymnet II ran in parallel with the original network, which continued to run on the Varian machines until it was phased out over a period of several years. Tymnet II's different method of constructing virtual circuits allowed for much better scalability.
In 1996, the third and final version of the Supervisor was written in C for a Sparc multiprocessor work station by Tymes and Romolo Raffo. Node code software was ported from the Tymnet Engine to a Sparc platform by Bill Soley.
In about 1979, Tymnet Inc. was spun off from Tymshare Inc. to continue administration and operation of the network. The network continued to grow, and customers who owned their own host computers and wanted access to them from remote sites became interested in connecting their computers to the network. This led to the foundation of Tymnet as a wholly owned subsidiary of Tymshare to run a public network as a common carrier within the United States. This allowed users to connect their host computers and terminals to the network, and use the computers from remote sites or sell time on their computers to other users of the network, with Tymnet charging them for the use of the network.
In 1984 Tymnet was bought by the McDonnell Douglas Corporation as part of the acquisition of Tymshare. The company was renamed McDonnell Douglas Tymshare, and began a major reorganization. A year later, McDonnell Douglas (MD) split Tymshare into several separate operating companies: MD Network Systems Company, MD Field Service Company, MD RCS, MD "xxx" and many more. (This is sometimes referred to the Alphabet Soup phase of the company). At this point, Tymnet had outlived its parent company Tymshare.
McDonnell Douglas acquired Microdata
and created MD Information Systems Group (MDISC), expecting to turn Microdata's desktop and server systems along with Tymshare's servers and Tymnet data network into a major player in the Information Services market. Microdata's systems were integrated into many parts of McDonnell Douglas, but Tymnet never was. MDC really did not seem to understand the telecommunications market. After five years, peace
was breaking out in many places in the world and McDonnell Douglas
sold off MDNSC and MDFSC at a profit for much needed cash.
Earlier, in 1986, the Canadian Radio-television and Telecommunications Commission (CRTC) liberalized the interconnection rules in the provinces it then regulated (Ontario, Quebec and British Columbia) and this allowed McDonnell Douglas to expand the network into select Canadian cities. The Canadian operation was part of McDonnell Douglas Computer Systems Company (MDCSC) as this was the only MDxxx company operating in Canada. MDCSC hired David Kingsland to spearhead this expansion into Canada.
On July 30, 1989 at the Mariott Hotel in Santa Clara, it was announced that British Telecom was purchasing McDonnell Douglas Network Systems Company, and McDonnell Douglas Field Service Company was being spun off as a start-up called NovaDyne. British Telecom (BT) wanted to expand and the acquisition of Tymnet which already a word-wide data network help to achieve that goal. On November 17, 1989 MDNSC officially became BT Tymnet with its headquarters in San Jose, California. BT brought with it the idea of continuous development with teams in America, Europe, and Asia-pacific all working together on the same projects. BT renamed the Tymnet services, Global Network Services (GNS).
British Telecom brought new life to the company with development of hardware and software for the Tymnet data network using contacts BT already had with telecommunication hardware vendors. There was a trial of "next-generation" nodes scattered throughout the network, called "TURBO engine nodes" based on the Motorola 68000
family. In the mid to late 1980s, serious node-code development was migrated from the PDP-10s to UNIX
. Sun-3
(based on the Motorola 68000) and later Sun-4
(SPARC based) workstations and servers were purchased from Sun Microsystems
, though the majority of PDP-10s were still around in the early '90s for legacy code, as well as documentation storage. Eventually, all of the code development trees were on the Sun-4s, and the development tools (NAD, etc.) had been ported to SunOS
.
Another project begun a few months before the BT purchase was to migrate the Tymnet code repository from the PDP-10s to Sun systems. The new servers were dubbed the Code Generation Systems or CGS. They were initially six Sun-3 servers upgraded eventually to two Sun-4/690 servers for redundancy. A second pair of servers for catastrophic failover were also installed in Malvern, PA and later moved to Norristown, PA as part of later site consolidation efforts. After the migration, there was code for more than 6000 nodes and 38,000 customer interfaces.
Tymnet was still growing, and at several times reached its peak capacity when some of its customers held network intensive events. One of these of note was a live, on-line presentation and chat on America On-Line
(AOL
) with Michael Jackson
. Tymnet usage statistics showed AOL's call capacity was greater than its maximum volume for the duration of the event.
(MCI) negotiated what they called the "Deal of the Century", where MCI would take ownership of the US-based portions of Tymnet and they would create a 50/50 joint venture called "Concert". (The joint venture was called "NewCo" for more than a year while they decided on a name.) Concert was also aligned with another acquisition of BT, called Syncordia which was headquartered in Atlanta, Ga. Tymnet was then referred to as: The Packet network, the BT/MCI network and Concert Packet-switching Services (CPS). At first, MCI only wanted to use the POPs or points of presence that Tymnet had because we have locations in over 150 cities in the US giving MCI more locations to provide local service. As MCI cut away at Tymnet, expecting it to die, it became a cash cow that just wouldn't go away.
In May 1994, there were still three DEC KL-10s under TYMCOM-X. At this time, the network had approximately 5000 nodes in 30 foreign countries. A variety of protocols can be run over a single packet-switching-network, and Tymnet's most-used protocols were X.25
, asynchronous (ATI/AHI), SNA.
BT and Concert also continued to develop the network, and after the failure of the "Turbo nodes" to take off, decided to have an outside company add Tymnet protocols to existing hardware used in their frame-relay
network. Telematics International developed a subset of the Tymnet protocols to run on their ACP/PCP nodes. The Telematics nodes were connected in a mesh network via Frame-relay
and appeared to Tymnet as super-nodes that were directly connected to as many as 44 other super-nodes interconnecting most of Europe, Asia and the Americas as a high speed data network.
MCI took a different direction and looked to migrate the network protocols to run over TCP/IP and use Sun Microsystems
SPARC
technology. The supervisor technology was rewritten in C to run as standard UNIX applications under Sun's Solaris operating system. Funding for this project was at a minimum but the Tymnet engineers believed it was a superior method and proceeded anyway.
Times were changing and the Internet
and World Wide Web
were becoming a practical and even important part of corporate and personal life. Tymnet technology needed improvements to keep pace with TCP/IP and other internet protocols. Both BT and MCI decided not to compete with the internet, but to convert their customer base to IP based networks and technologies. However, the Tymnet network was still bringing in lots of cash (in some cases more than current IP based services), so both BT and MCI needed to keep their customers happy.
Concert created Project Leonardo to separate the BT and MCI/Worldcom voice and data networks. At times over the next five years, advancements were made or stalled due to BT and MCI management negotiating and renegotiating the terms of their contractual obligations to each other made during the alliance. At times, things came to a standstill, or decisions made were reversed, and some reversed again at a later time. Parts of the project were to migrate customers from X.25 to IP based networks, while others created a duplicate set of services so that both Concert and MCI could separately continue to run and manage their own portions of the network. Accounting data for network usage was also shared by the two companies and had to be separated before clients could be billed properly.
, moving the headquarters to Atlanta, Georgia. This alliance did not help the negotiations between BT and MCI Worldcom as their partners from MCI and AT&T were corporate enemies. For Tymnet, the data network portion of the split, and the "CPS Leonardo" project, the split was never fully realized. Instead, MCI Worldcom completed their migration of services from Tymnet to IP based services in March 2003 and disconnected their supervisor nodes and their portion of the network on March 31, 2003. British Telecom continued to run the network using their own supervisor and other utility nodes until February 2004 when their last customer was able to move all of its customers to other access services. BT and AT&T dissolved their Concert alliance on September 30, 2003 and the remaining BT assets were combined with BTNA assets into BT Americas, Inc. Sometime in early March 2004, without ceremony, BT Americas disconnected the last two remaining Tymnet supervisors from the network, effectively shutting it down.
This scandal sent the stock price down to ten cents per share, and Worldcom filed for bankruptcy. It came out of bankruptcy renamed as "MCI" several months later.
Shortly thereafter the name was changed to AT&T Inc. to distinguish itself from AT&T Corp.
Verizon was formed in 2000 when Bell Atlantic, one of the Regional Bell Operating Companies, merged with GTE
. Prior to its transformation into Verizon, Bell Atlantic had merged with another Regional Bell Operating Company, NYNEX
, in 1997
Tymshare was one of the pioneers in the EDI field. Under McDonnell Douglas
, the Payment Systems Company continued that legacy and maintained its own network monitoring and support group. They used Tandem
computers connected to a high speed data link using Tymnet as the connection and translation medium. Tymshare developed a bi-sync modem interface (HSA), a translation module to translate between EBCDIC
and ASCII
(BBXS), and a highly customized x.25 module (XCOM) to interface with the Tandem computers.
Apparently, there was no TCP/IP equivalent service, so to continue use of this service after the shutdown of Tymnet, an ingenious solution was selected. A special version of Tymnet Engine node code which allows nodes and interfaces to communicate with one another and the rest of the network was created. Instead of relying on the "supervisor" to validate calls, a table of permitted connections was defined per customer to allow an incoming call to be made from the HSA interface to the BBXS interface to the XCOM interface and on to the Tandem computer. In effect, they created a "Tymnet Island" consisting of a single Tymnet node that accepted calls for a pre-determined list of clients. No supervisor needed.
These islands of Tymnet have not only outlived the parent company, Tymshare, and the operations company, Tymnet, but also the Tymnet Network itself. As of 2008, these Tymnet Island nodes are still running and doing their jobs.
DECSystem-10 computers that Tymshare offered as timesharing hosts for their customers. Tymnet operations formed a strategic alliance with the Tymshare PDP-10 TYMCOM-X operating systems group to assist them in developing new network management tools.
system for TOPS-10
published by Software House). He called the program PAPER after the old manual way of managing trouble tickets. The program grew as features were added to handle customer information, call-back contact information, escalation procedures, and outage statistics.
computers, model KL-1090, accessible via the Tymnet Packet Network as Tymshare hosts 23 and 26. Each computer was the size of 5 refrigerators, and had a string of disks that looked like 18 washing machines. Their power supplies produced +5 volts at 200 amps (non-switching) making them expensive to operate.
and HTTP. A low-end workstation
from Sun was used as a telnet
gateway; it accepted logins from the Tymnet network via x.25 to IP translation done by a Cisco router forwarded to "ticket" and/or "token". The XKL TOAD-1 systems ran a modified TOPS-20
. The application was ported to a newer version of the Fortran
compiler, and still used the 1022 database.
In January 1999, both XKL servers (ticket and token) were decommissioned. In late 2003 the hardware left onsite in San Jose was accidentally scrapped by the facilities manager during a scheduled cleanup.
San Jose, California
San Jose is the third-largest city in California, the tenth-largest in the U.S., and the county seat of Santa Clara County which is located at the southern end of San Francisco Bay...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
that used virtual call packet switched technology and X.25
X.25
X.25 is an ITU-T standard protocol suite for packet switched wide area network communication. An X.25 WAN consists of packet-switching exchange nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links...
, SNA
Systems Network Architecture
Systems Network Architecture is IBM's proprietary networking architecture created in 1974. It is a complete protocol stack for interconnecting computers and their resources. SNA describes the protocol and is, in itself, not actually a program...
/SDLC
Synchronous Data Link Control
Synchronous Data Link Control is a computer communications protocol. It is the layer 2 protocol for IBM's Systems Network Architecture . SDLC supports multipoint links as well as error correction. It also runs under the assumption that an SNA header is present after the SDLC header...
, ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
and BSC
Binary Synchronous Communications
Binary Synchronous Communication is an IBM link protocol, announced in 1967 after the introduction of System/360. It replaced the synchronous-transmit-receive protocol used with second generation computers. The intent was that common link management rules could be used with three different...
interfaces to connect host computers (servers) at thousands of large companies, educational institutions, and government agencies. Users typically connected via dial-up connections or dedicated async connections. The business consisted of a large public network that supported dial-up users and a private network business that allowed government agencies and large companies (mostly banks and airlines) to build their own dedicated networks. The private networks were often connected via gateways to the public network to reach locations not on the private network. Tymnet was also connected to dozens of other public networks in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and internationally via X.25/X.75
X.75
X.75 is an International Telecommunication Union standard specifying the interface for interconnecting two X.25 networks. X.75 is almost identical to X.25...
gateways.
As the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
grew and became almost universally accessible in the late 1990s, the need for services such as Tymnet migrated to the Internet style connections, but still had some value in the third world
Third World
The term Third World arose during the Cold War to define countries that remained non-aligned with either capitalism and NATO , or communism and the Soviet Union...
and for specific legacy roles. However the value of these links continued to decrease, and Tymnet was officially shut down in 2004.
Network
Tymnet offered local dial-up modemModem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
access in most cities in the United States and to a limited degree in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, which preferred its own DATAPAC
DATAPAC
DATAPAC was Canada's packet switched X.25-equivalent data network. Operated first by Trans-Canada Telephone System, then Telecom Canada, then the Stentor Alliance, it finally reverted to Bell Canada when the Stentor Alliance was dissolved.-Use:...
service.
Tymnet was extensively used by large companies to provide dial-up services for their employees who were "on the road", as well as a gateway for users to connect to large online services such as CompuServe
CompuServe
CompuServe was the first major commercial online service in the United States. It dominated the field during the 1980s and remained a major player through the mid-1990s, when it was sidelined by the rise of services such as AOL with monthly subscriptions rather than hourly rates...
or The Source
The Source (service)
The Source was an early online service, one of the first such services to be oriented toward and available to the general public. The Source described itself as follows:...
.
Organization and functionality
In its original implementation, the network supervisor contained most of the routing intelligence in the network. Unlike the TCP/IP protocol underlying the internet, Tymnet used a circuit switchingCircuit switching
Circuit switching is a methodology of implementing a telecommunications network in which two network nodes establish a dedicated communications channel through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the...
layout which allowed the supervisors to be aware of every possible end-point. In its original incarnation, the users connected to nodes built using Varian
Varian Data Machines
Varian Data Machines was a division of Varian Associates which sold minicomputers. It entered the market in 1966, but met stiff competition and was bought by Sperry Corporation in 1977....
minicomputers, then entered commands that were passed to the supervisor which ran on a XDS 940
SDS 940
The SDS 940 was Scientific Data Systems' first machine designed to support time sharing directly, and was based on the SDS 930's 24-bit CPU built primarily of integrated circuits. It was announced in February 1966 and shipped in April, becoming a major part of Tymshare's expansion during the 1960s...
host.
Circuits were character oriented and the network was oriented towards interactive character-by-character full-duplex
Duplex (telecommunications)
A duplex communication system is a system composed of two connected parties or devices that can communicate with one another in both directions. The term multiplexing is used when describing communication between more than two parties or devices....
communications circuits. The nodes handled character translation between various character sets, which were numerous at that point in time. This did have the side effect of making data transfers quite difficult, as byte
Byte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...
s from the file would be invisibly "translated" without specific intervention on the part of the user.
Tymnet later developed their own custom hardware, the Tymnet Engine, which contained both nodes and a supervisor running on one of those nodes. As the network grew, the supervisor was in danger of being overloaded by the sheer number of nodes in the network, since the requirements for controlling the network took a great part of the supervisor's capacity.
Tymnet II was developed in response to this challenge. Tymnet II was developed to ameliorate the problems outlined above by off-loading some of the work-load from the supervisor and providing greater flexibility in the network by putting more intelligence into the node code. A Tymnet II node would set up its own "permuter tables", eliminating the need for the supervisor to keep copies of them, and had greater flexibility in handling its inter-node links. Data transfers were also possible via "auxiliary circuits".
Beginnings: Tymshare
TymshareTymshare
Tymshare, Inc. was headquartered in Cupertino, California from 1964 to 1984.It was a well-known timesharing service and third-party hardware maintenance company throughout its history and competed with companies such as Four Phase, Compuserve, and Digital Equipment Corporation...
was founded in 1964 as a time sharing company, selling computer time and software packages for users. It had two SDS/XDS
Scientific Data Systems
Scientific Data Systems, or SDS, was an American computer company founded in September 1961 by Max Palevsky, a veteran of Packard Bell and Bendix, along with eleven other computer scientists. SDS was an early adopter of integrated circuits in computer design and the first to employ silicon...
940 computers; access was via direct dial-up to the computers. In 1968, it purchased Dial Data, another time-sharing service bureau.
In 1968, Norm Hardy and LaRoy Tymes developed the idea of using remote sites with minicomputers to communicate with the mainframes. The minicomputers would serve as the network's nodes, running a program called a "supervisor" to route data. In November 1971, the first Tymnet Supervisor program became operational. Written in assembly code by LaRoy Tymes for the SDS 940, with architectural design contributions from Norman Hardy, the "Supervisor" was the beginning of the Tymnet network. The Varian
Varian Data Machines
Varian Data Machines was a division of Varian Associates which sold minicomputers. It entered the market in 1966, but met stiff competition and was bought by Sperry Corporation in 1977....
620i (8K of 16 bit words) was used for the TYMNET nodes. Initially, Tymshare and its direct customers were the network's only users. In February, 1972, the National Library of Medicine became the first non-Tymshare network customer with a toxicology data base on an IBM 360.
It soon became apparent that the SDS 940 could not keep up with the rapid growth of the network. In 1972, Joseph Rinde joined the Tymnet group and began porting the Supervisor code to the 32-bit Interdata 7/32
Interdata 7/32 and 8/32
The Model 7/32 and Model 8/32 were 32-bit minicomputers developed by Interdata, Inc. of Oceanport, New Jersey during the 1970s. They are primarily remembered for being the first 32-bit minicomputers, and the first non-PDP computers to run Unix...
, as the 8/32 was not yet ready. In 1973, the 8/32 became available, but the performance was disappointing and a crash-effort was made to develop a machine that could run Rinde's Supervisor.
In 1974, a second, more efficient version of the Supervisor software became operational. The new Tymnet "Engine" software was used on both the Supervisor machines and on the nodes.
After the migration to the Tymnet Engine, they started developing Tymnet accounting and other support software on the PDP-10
PDP-10
The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
. Tymshare sold the Tymnet network software to TRW
TRW
TRW Inc. was an American corporation involved in a variety of businesses, mainly aerospace, automotive, and credit reporting. It was a pioneer in multiple fields including electronic components, integrated circuits, computers, software and systems engineering. TRW built many spacecraft,...
, who created their own private network, TRWNET.
Tymes and Rinde then developed "Tymnet II". Tymnet II ran in parallel with the original network, which continued to run on the Varian machines until it was phased out over a period of several years. Tymnet II's different method of constructing virtual circuits allowed for much better scalability.
In 1996, the third and final version of the Supervisor was written in C for a Sparc multiprocessor work station by Tymes and Romolo Raffo. Node code software was ported from the Tymnet Engine to a Sparc platform by Bill Soley.
Tymnet, Inc. spun off
Sold to McDonnell Douglas
McDonnell Douglas TymshareIn 1984 Tymnet was bought by the McDonnell Douglas Corporation as part of the acquisition of Tymshare. The company was renamed McDonnell Douglas Tymshare, and began a major reorganization. A year later, McDonnell Douglas (MD) split Tymshare into several separate operating companies: MD Network Systems Company, MD Field Service Company, MD RCS, MD "xxx" and many more. (This is sometimes referred to the Alphabet Soup phase of the company). At this point, Tymnet had outlived its parent company Tymshare.
McDonnell Douglas acquired Microdata
Microdata
Microdata Corporation was an Irvine, California based computer company, developing hardware and operating systems to run its REALITY environment...
and created MD Information Systems Group (MDISC), expecting to turn Microdata's desktop and server systems along with Tymshare's servers and Tymnet data network into a major player in the Information Services market. Microdata's systems were integrated into many parts of McDonnell Douglas, but Tymnet never was. MDC really did not seem to understand the telecommunications market. After five years, peace
Peace
Peace is a state of harmony characterized by the lack of violent conflict. Commonly understood as the absence of hostility, peace also suggests the existence of healthy or newly healed interpersonal or international relationships, prosperity in matters of social or economic welfare, the...
was breaking out in many places in the world and McDonnell Douglas
McDonnell Douglas
McDonnell Douglas was a major American aerospace manufacturer and defense contractor, producing a number of famous commercial and military aircraft. It formed from a merger of McDonnell Aircraft and Douglas Aircraft in 1967. McDonnell Douglas was based at Lambert-St. Louis International Airport...
sold off MDNSC and MDFSC at a profit for much needed cash.
Earlier, in 1986, the Canadian Radio-television and Telecommunications Commission (CRTC) liberalized the interconnection rules in the provinces it then regulated (Ontario, Quebec and British Columbia) and this allowed McDonnell Douglas to expand the network into select Canadian cities. The Canadian operation was part of McDonnell Douglas Computer Systems Company (MDCSC) as this was the only MDxxx company operating in Canada. MDCSC hired David Kingsland to spearhead this expansion into Canada.
Sold to British Telecom
BT Tymnet, BT North America, BTNAOn July 30, 1989 at the Mariott Hotel in Santa Clara, it was announced that British Telecom was purchasing McDonnell Douglas Network Systems Company, and McDonnell Douglas Field Service Company was being spun off as a start-up called NovaDyne. British Telecom (BT) wanted to expand and the acquisition of Tymnet which already a word-wide data network help to achieve that goal. On November 17, 1989 MDNSC officially became BT Tymnet with its headquarters in San Jose, California. BT brought with it the idea of continuous development with teams in America, Europe, and Asia-pacific all working together on the same projects. BT renamed the Tymnet services, Global Network Services (GNS).
British Telecom brought new life to the company with development of hardware and software for the Tymnet data network using contacts BT already had with telecommunication hardware vendors. There was a trial of "next-generation" nodes scattered throughout the network, called "TURBO engine nodes" based on the Motorola 68000
Motorola 68000
The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor...
family. In the mid to late 1980s, serious node-code development was migrated from the PDP-10s to 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...
. Sun-3
Sun-3
Sun-3 was the name given to a series of UNIX computer workstations and servers produced by Sun Microsystems, launched on September 9th, 1985. The Sun-3 series were VMEbus-based systems similar to some of the earlier Sun-2 series, but using the Motorola 68020 microprocessor, in combination with the...
(based on the Motorola 68000) and later Sun-4
Sun-4
Sun-4 is a series of Unix workstations and servers produced by Sun Microsystems, launched in 1987. The original Sun-4 series were VMEbus-based systems similar to the earlier Sun-3 series, but employing microprocessors based on Sun's own SPARC V7 RISC architecture in place of the 68k family...
(SPARC based) workstations and servers were purchased from Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
, though the majority of PDP-10s were still around in the early '90s for legacy code, as well as documentation storage. Eventually, all of the code development trees were on the Sun-4s, and the development tools (NAD, etc.) had been ported to SunOS
SunOS
SunOS is a version of the Unix operating system developed by Sun Microsystems for their workstation and server computer systems. The SunOS name is usually only used to refer to versions 1.0 to 4.1.4 of SunOS...
.
Another project begun a few months before the BT purchase was to migrate the Tymnet code repository from the PDP-10s to Sun systems. The new servers were dubbed the Code Generation Systems or CGS. They were initially six Sun-3 servers upgraded eventually to two Sun-4/690 servers for redundancy. A second pair of servers for catastrophic failover were also installed in Malvern, PA and later moved to Norristown, PA as part of later site consolidation efforts. After the migration, there was code for more than 6000 nodes and 38,000 customer interfaces.
Tymnet was still growing, and at several times reached its peak capacity when some of its customers held network intensive events. One of these of note was a live, on-line presentation and chat on America On-Line
AOL
AOL Inc. is an American global Internet services and media company. AOL is headquartered at 770 Broadway in New York. Founded in 1983 as Control Video Corporation, it has franchised its services to companies in several nations around the world or set up international versions of its services...
(AOL
AOL
AOL Inc. is an American global Internet services and media company. AOL is headquartered at 770 Broadway in New York. Founded in 1983 as Control Video Corporation, it has franchised its services to companies in several nations around the world or set up international versions of its services...
) with Michael Jackson
Michael Jackson
Michael Joseph Jackson was an American recording artist, entertainer, and businessman. Referred to as the King of Pop, or by his initials MJ, Jackson is recognized as the most successful entertainer of all time by Guinness World Records...
. Tymnet usage statistics showed AOL's call capacity was greater than its maximum volume for the duration of the event.
MCI, NewCo, Concert
In 1993 British Telecom (BT) and MCI CommunicationsMCI Communications
MCI Communications Corp. was an American telecommunications company that was instrumental in legal and regulatory changes that led to the breakup of the AT&T monopoly of American telephony and ushered in the competitive long-distance telephone industry. It was headquartered in Washington,...
(MCI) negotiated what they called the "Deal of the Century", where MCI would take ownership of the US-based portions of Tymnet and they would create a 50/50 joint venture called "Concert". (The joint venture was called "NewCo" for more than a year while they decided on a name.) Concert was also aligned with another acquisition of BT, called Syncordia which was headquartered in Atlanta, Ga. Tymnet was then referred to as: The Packet network, the BT/MCI network and Concert Packet-switching Services (CPS). At first, MCI only wanted to use the POPs or points of presence that Tymnet had because we have locations in over 150 cities in the US giving MCI more locations to provide local service. As MCI cut away at Tymnet, expecting it to die, it became a cash cow that just wouldn't go away.
In May 1994, there were still three DEC KL-10s under TYMCOM-X. At this time, the network had approximately 5000 nodes in 30 foreign countries. A variety of protocols can be run over a single packet-switching-network, and Tymnet's most-used protocols were X.25
X.25
X.25 is an ITU-T standard protocol suite for packet switched wide area network communication. An X.25 WAN consists of packet-switching exchange nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links...
, asynchronous (ATI/AHI), SNA.
BT and Concert also continued to develop the network, and after the failure of the "Turbo nodes" to take off, decided to have an outside company add Tymnet protocols to existing hardware used in their frame-relay
Frame relay
Frame Relay is a standardized wide area network technology that specifies the physical and logical link layers of digital telecommunications channels using a packet switching methodology...
network. Telematics International developed a subset of the Tymnet protocols to run on their ACP/PCP nodes. The Telematics nodes were connected in a mesh network via Frame-relay
Frame relay
Frame Relay is a standardized wide area network technology that specifies the physical and logical link layers of digital telecommunications channels using a packet switching methodology...
and appeared to Tymnet as super-nodes that were directly connected to as many as 44 other super-nodes interconnecting most of Europe, Asia and the Americas as a high speed data network.
MCI took a different direction and looked to migrate the network protocols to run over TCP/IP and use Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
technology. The supervisor technology was rewritten in C to run as standard UNIX applications under Sun's Solaris operating system. Funding for this project was at a minimum but the Tymnet engineers believed it was a superior method and proceeded anyway.
Times were changing and the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
and World Wide Web
World Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...
were becoming a practical and even important part of corporate and personal life. Tymnet technology needed improvements to keep pace with TCP/IP and other internet protocols. Both BT and MCI decided not to compete with the internet, but to convert their customer base to IP based networks and technologies. However, the Tymnet network was still bringing in lots of cash (in some cases more than current IP based services), so both BT and MCI needed to keep their customers happy.
MCI, MCI Worldcom, Worldcom vs. BT, Concert, AT&T
In 1997 talks were underway for British Telecom (BT) to acquire MCI. The deal fell through, and in September, 1998 MCI was acquired by WorldCom after they made a better offer for the company. Actually, the Worldcom offer was nearly identical to the BT offer, but where BT planned to buy out MCI shares of stock, WorldCom offered a stock-swap which was more attractive to the stockholders. Worldcom took control in September 1998 and dissolved the BT/MCI alliance as of October 15, 1998.Concert - headquarters in Reston, Va.
With the alliance gone, BT and MCI/Worldcom began the process of unraveling and separating their extensive voice and data communications systems.Concert created Project Leonardo to separate the BT and MCI/Worldcom voice and data networks. At times over the next five years, advancements were made or stalled due to BT and MCI management negotiating and renegotiating the terms of their contractual obligations to each other made during the alliance. At times, things came to a standstill, or decisions made were reversed, and some reversed again at a later time. Parts of the project were to migrate customers from X.25 to IP based networks, while others created a duplicate set of services so that both Concert and MCI could separately continue to run and manage their own portions of the network. Accounting data for network usage was also shared by the two companies and had to be separated before clients could be billed properly.
Concert - headquarters in Atlanta, Ga.
In 2000 BT then went searching for another alliance, and created a new "Concert" alliance between BT and AT&TAT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
, moving the headquarters to Atlanta, Georgia. This alliance did not help the negotiations between BT and MCI Worldcom as their partners from MCI and AT&T were corporate enemies. For Tymnet, the data network portion of the split, and the "CPS Leonardo" project, the split was never fully realized. Instead, MCI Worldcom completed their migration of services from Tymnet to IP based services in March 2003 and disconnected their supervisor nodes and their portion of the network on March 31, 2003. British Telecom continued to run the network using their own supervisor and other utility nodes until February 2004 when their last customer was able to move all of its customers to other access services. BT and AT&T dissolved their Concert alliance on September 30, 2003 and the remaining BT assets were combined with BTNA assets into BT Americas, Inc. Sometime in early March 2004, without ceremony, BT Americas disconnected the last two remaining Tymnet supervisors from the network, effectively shutting it down.
Worldcom bankruptcy
Worldcom executives were involved in a financial scandal resulting in the CEO, Bernie Ebbers, to be ousted and later brought up on federal charges.This scandal sent the stock price down to ten cents per share, and Worldcom filed for bankruptcy. It came out of bankruptcy renamed as "MCI" several months later.
AT&T sold to SBC
On January 31, 2005, SBC Communications announced that it would purchase AT&T Corp. for more than $16 billion.Shortly thereafter the name was changed to AT&T Inc. to distinguish itself from AT&T Corp.
MCI sold to Verizon
On February 14, 2005, Verizon agreed to acquire MCI, formerly WorldCom, after SBC Communications agreed to acquire AT&T Corp. just a few weeks earlier.Verizon was formed in 2000 when Bell Atlantic, one of the Regional Bell Operating Companies, merged with GTE
GTE
GTE Corporation, formerly General Telephone & Electronics Corporation was the largest independent telephone company in the United States during the days of the Bell System....
. Prior to its transformation into Verizon, Bell Atlantic had merged with another Regional Bell Operating Company, NYNEX
NYNEX
NYNEX Corporation was a telephone company that served five New England states as well as most of New York state, except the Rochester area, from 1984 through 1997....
, in 1997
Electronic Data Interchange (EDI)
Tymshare EDI, MD Payment Systems Company, MCI EDI DepartmentTymshare was one of the pioneers in the EDI field. Under McDonnell Douglas
McDonnell Douglas
McDonnell Douglas was a major American aerospace manufacturer and defense contractor, producing a number of famous commercial and military aircraft. It formed from a merger of McDonnell Aircraft and Douglas Aircraft in 1967. McDonnell Douglas was based at Lambert-St. Louis International Airport...
, the Payment Systems Company continued that legacy and maintained its own network monitoring and support group. They used Tandem
Tandem
Tandem is an arrangement where a team of machines, animals or people are lined up one behind another, all facing in the same direction....
computers connected to a high speed data link using Tymnet as the connection and translation medium. Tymshare developed a bi-sync modem interface (HSA), a translation module to translate between EBCDIC
EBCDIC
Extended Binary Coded Decimal Interchange Code is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems....
and ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
(BBXS), and a highly customized x.25 module (XCOM) to interface with the Tandem computers.
Apparently, there was no TCP/IP equivalent service, so to continue use of this service after the shutdown of Tymnet, an ingenious solution was selected. A special version of Tymnet Engine node code which allows nodes and interfaces to communicate with one another and the rest of the network was created. Instead of relying on the "supervisor" to validate calls, a table of permitted connections was defined per customer to allow an incoming call to be made from the HSA interface to the BBXS interface to the XCOM interface and on to the Tandem computer. In effect, they created a "Tymnet Island" consisting of a single Tymnet node that accepted calls for a pre-determined list of clients. No supervisor needed.
These islands of Tymnet have not only outlived the parent company, Tymshare, and the operations company, Tymnet, but also the Tymnet Network itself. As of 2008, these Tymnet Island nodes are still running and doing their jobs.
Organization
In operation, Tymshare's Data Networks Division was responsible for the development and maintenance of the network and Tymnet was responsible for the administration, provisioning and monitoring of the network. Each company had their own software development staff and a line was drawn to separate what each group could do. Tymshare development engineers wrote all the code which ran in the network, and the Tymnet staff wrote code running on host computers connected to the network. It is for this reason, that many of the Tymnet projects ran on the 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...
DECSystem-10 computers that Tymshare offered as timesharing hosts for their customers. Tymnet operations formed a strategic alliance with the Tymshare PDP-10 TYMCOM-X operating systems group to assist them in developing new network management tools.
Origins
Trouble reports were initially tracked on pieces of paper. This was until a manager at Tymnet wrote a small FORTRAN IV program to maintain a list of problem reports and track their status in a System 1022 database (a hierarchical databaseHierarchical model
A hierarchical database model is a data model in which the data is organized into a tree-like structure. The structure allows representing information using parent/child relationships: each parent can have many children, but each child has only one parent...
system for TOPS-10
TOPS-10
The TOPS-10 System was a computer operating system from Digital Equipment Corporation for the PDP-10 mainframe computer launched in 1967...
published by Software House). He called the program PAPER after the old manual way of managing trouble tickets. The program grew as features were added to handle customer information, call-back contact information, escalation procedures, and outage statistics.
Company-wide use
Access to PAPER became critical as more and more functionality was added. It eventually was maintained on two dedicated PDP-10PDP-10
The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
computers, model KL-1090, accessible via the Tymnet Packet Network as Tymshare hosts 23 and 26. Each computer was the size of 5 refrigerators, and had a string of disks that looked like 18 washing machines. Their power supplies produced +5 volts at 200 amps (non-switching) making them expensive to operate.
Major upgrades
In 1996 the DEC PDP-10s that ran Tymnet's trouble-ticket system were replaced by PDP-10 clones from XKL, Inc. They were accessible via TCP/IP as ticket.tymnet.com and token.tymnet.com, by both TELNETTELNET
Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection...
and HTTP. A low-end workstation
Workstation
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems...
from Sun was used as a telnet
TELNET
Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection...
gateway; it accepted logins from the Tymnet network via x.25 to IP translation done by a Cisco router forwarded to "ticket" and/or "token". The XKL TOAD-1 systems ran a modified TOPS-20
TOPS-20
The TOPS-20 operating system by Digital Equipment Corporation was the second proprietary OS for the PDP-10 mainframe computer. TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman...
. The application was ported to a newer version of the Fortran
Fortran
Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
compiler, and still used the 1022 database.
Decommission
In mid to late 1998, Concert produced an inter-company trouble tracking system for use by both MCI and Concert. This was adopted and the TTS PAPER data necessary for ongoing tickets was re-entered on the new system. TTS was kept up for historical information until the end of the year.In January 1999, both XKL servers (ticket and token) were decommissioned. In late 2003 the hardware left onsite in San Jose was accidentally scrapped by the facilities manager during a scheduled cleanup.