This is an incomplete list of central office (telephone company

Telephone company

A telephone company is a service provider of telecommunications services such as telephony and data communications access. Many were at one time nationalized or state-regulated monopolies...

 operated) telephone switches.

Alcatel

Alcatel

Alcatel Mobile Phones is a brand of mobile handsets. It was established in 2004 as a joint venture between Alcatel-Lucent of France and TCL Communication of China....

See also Lucent

• E10 FIVE
• E10MT
• E10B
• System 12 (formerly ITT 1240)
• System 12 Remote Switching Unit (RSU)
• OCB-283 (1000E10 Digital Family)
• OmniPCX Office
• OmniPCX Enterprise

Automatic Electric

• 32A42
• 32A44
• 35E97
• 370A
• 370B
• 375A
• 375B
• 385A
• 385B
• C1-EAX
• CXP5
• CXP5A
• EAX1
• EAX2
• EAX3
• ESU 3072 Line
• FW1
• GTD-3 EAX (Toll switch, NOT CCS7 capable)
• GTD-5 EAX
  GTD-5 EAX
  The GTD-5 EAX is the Class 5 telephone switch developed by GTE Automatic Electric Laboratories...
  
   (Class 5 switch, many in use today, was the primary switch in former GTE exchanges. Now supported by Lucent.)
• XPT No. 1
• SATT
• TSPS (Traffic Service Position System, obsolete system for operator handled LD calls.)
• 101 Director
• OXO
• OXE

Avaya

Avaya

Avaya Inc. is a privately held computer networking, information technology and telecommunications company that is a global provider of business communications systems. The international head quarters is in Basking Ridge, New Jersey, United States...

• Currently Available Avaya Switches
  • Application Server 5300 (AS5300)
  • Communication Manager
  • S8800
  • S8730
  • S8510
  • S8400
  • S8300D
  • INDeX
  • IP Office
  • PARTNER ACS (Advanced Communications System)
  • PARTNER Small Office Edition

• Discontinued Avaya Switches
  • 1A2 Key System
    1A2 Key System
    The 1A2 Key System is an analog multiline business key telephone system. Unlike more modern multiline systems, every telephone line serving a particular phone is wired into that phone, and electromechanical switches switch the lines in the phone itself...
    
     (Electro-mechanical Key System made by Western Electric)
  • DEFINITY BCS (Business Communications System)
  • DEFINITY ECS (Enterprise Communications Server)
  • DEFINITY G3R (Rack)
  • DEFINITY Communications System Generic 2 (Formerly, System 85)
  • DEFINITY Communications System Generic 3 (Formerly System 75)
  • DIMENSION (Previously made by AT&T)
  • G3MCC (Multi-Carrier Cabinet)
  • HORIZON (Previously made by AT&T)
  • MERLIN
    AT&T Merlin
    The AT&T Merlin telephone system was introduced in late 1983, branded American Bell Merlin. After the breakup of AT&T in 1984, it was rebranded AT&T Merlin. It was designed at the beginning of the 1980s prior to the Bell System Divestiture as a modern electronic replacement for the dated...
    
     ("Classic", Originally made by AT&T)
  • MERLIN PLUS ("Classic", Originally made by AT&T)
  • MERLIN II ("Classic", Originally made by AT&T)
  • MERLIN LEGEND
  • MERLIN MAGIX, Integrated Communications System
  • PARTNER
  • PARTNER II
  • PARTNER PLUS
  • S8700 & S8720
  • S8500
  • S8300 a,b & c
  • SPIRIT
  • System 25 (Previously made by AT&T)
  • System 75 (Previously made by AT&T)
  • System 75 XE (Previously made by AT&T)
  • System 85 (Previously made by AT&T)

GPO/PO/British Telecommunications

• TXS
• IAX5 Island Automatic eXchange No 5
• UAX5
• UAX6
• UAX7
• UAX8
• UAX9
• UAX10
• UAX11
• UAX12
• UAX13
• UAX14
• UXE7
• UXE8
• TXK
  TXK
  TXK was a range of Crossbar exchanges used by the British Post Office telephone network, subsequently BT, between 1964 and 1994. TXC was used as the designation at first, but this was later changed as TXC sounded too much like TXE the code used for later electronic exchanges...
  
  1
• TXK
  TXK
  TXK was a range of Crossbar exchanges used by the British Post Office telephone network, subsequently BT, between 1964 and 1994. TXC was used as the designation at first, but this was later changed as TXC sounded too much like TXE the code used for later electronic exchanges...
  
  5
• TXE
  TXE
  TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office , now BT, designed to replace the ageing Strowger systems....
  
  1
• TXE
  TXE
  TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office , now BT, designed to replace the ageing Strowger systems....
  
  2
• TXE
  TXE
  TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office , now BT, designed to replace the ageing Strowger systems....
  
  3
• TXE
  TXE
  TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office , now BT, designed to replace the ageing Strowger systems....
  
  4
• TXE
  TXE
  TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office , now BT, designed to replace the ageing Strowger systems....
  
  4A
• TXE
  TXE
  TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office , now BT, designed to replace the ageing Strowger systems....
  
  4E
• TXE
  TXE
  TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office , now BT, designed to replace the ageing Strowger systems....
  
  5
• TXE
  TXE
  TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office , now BT, designed to replace the ageing Strowger systems....
  
  6
• System X
  System X (telephony)
  System X was the name of the UK's first national digital telephone exchange system.-Development:System X was developed by the UK Post Office , GEC, Plessey, and Standard Telephones and Cables and first shown in public in 1979 at the Telecom 79 exhibition in Geneva Switzerland...
  
  
• System Y
  System Y
  System Y is a digital telephone exchange system used by British Telecom, the operator of the United Kingdom's telephone network.British Telecom decided to use the AXE10 digital switch in the mid-1980s to end its total reliance on GEC's System X. This also kept GEC from using a position of...
  
   (Ericsson AXE)
• UXD5

Digium

The Asterisk PBX is not exactly a phone exchange per se, but a software implementation of a PBX that runs on a PC, using the computer's network interface to handle voice over IP

Voice over IP

Voice over Internet Protocol is a family of technologies, methodologies, communication protocols, and transmission techniques for the delivery of voice communications and multimedia sessions over Internet Protocol networks, such as the Internet...

, and PCI cards sold by Digium to connect to the phone network.

• Asterisk PBX
  Asterisk PBX
  Asterisk is a software implementation of a telephone private branch exchange ; it was created in 1999 by Mark Spencer of Digium. Like any PBX, it allows attached telephones to make calls to one another, and to connect to other telephone services including the public switched telephone network and...
  
  

DSC Communications Corp.

DSC merged with Alcatel-Lucent

Alcatel-Lucent

Alcatel-Lucent is a global telecommunications corporation, headquartered in the 7th arrondissement of Paris, France. It provides telecommunications solutions to service providers, enterprises, and governments around the world, enabling these customers to deliver voice, data, and video services...

• DEX 200
• DEX 400
• DEX 600
• DEX 600E
• DEX 600SC

Electronics and Telecommunications Research Institute (Korea)

The TDX switch was a joint project with Korea Telecom

Korea Telecom

KT Corporation is a South Korean integrated wired/wireless telecommunication service provider. KT has an information & communications business, and has the largest portion of the South Korean local telephone and high-speed Internet business...

 and four manufacturers, LG Electronics, Samsung Telecommunications

Samsung

The Samsung Group is a South Korean multinational conglomerate corporation headquartered in Samsung Town, Seoul, South Korea...

, Daewoo Telecom

Daewoo

Daewoo or the Daewoo Group was a major South Korean chaebol . It was founded on 22 March 1967 as Daewoo Industrial and was dismantled by the Korean government in 1999...

 and Hanwha Telecom

Hanwha

Hanwha Group is one of the largest business conglomerate in South Korea. Founded in 1952 as Korea Explosives Inc. , the group has grown into a large multi-profile business conglomerate, with diversified holdings stretching from explosives, their original business, to retail to financial...

.

• TDX-1
• TDX-10
• TDX-100

Ericsson

Ericsson

Ericsson , one of Sweden's largest companies, is a provider of telecommunication and data communication systems, and related services, covering a range of technologies, including especially mobile networks...

• AGF
• AKE
• AR10
• ARB (telex)
• ARE11
• ARE13
• ARF10
• ARF101
• ARF102
• ARK-D (decadic signalling)
• ARK-M (mfc signalling)
• ARK523 (small minor switching centre)
• ARM20
• ARM50
• ARM 201
• ARM202
• ATE
• ATE-NB
• ATE-VB
• AXE
  AXE telephone exchange
  The AXE telephone exchange is a product line of circuit switched digital telephone exchanges manufactured by Ericsson, a Swedish telecom company. It was developed in 1974 by Ellemtel, a research and development subsidiary of Ericsson and Televerket.. The first system was deployed in 1976...
  
   10
  • AXE 10 Remote
  • AXE Local 7
  • AXE Transgate
• AXE810
• MD110
• MX-ONE
• Rurax

Fujitsu

Fujitsu

is a Japanese multinational information technology equipment and services company headquartered in Tokyo, Japan. It is the world's third-largest IT services provider measured by revenues....

• C140
• C460
• Focus I
• Focus II
• Focus III
• Focus 50
• Focus 100
• Focus 196
• Focus 960
• Focus Elite
• FETEX 100
• FETEX 150
  • FETEX 150 Local
  • FETEX 150 Toll
• Essence 630
• Essence 650
• 9600 Series
  • 9600VS
  • 9600S
  • 9600M
  • 9600L
• Coral (branded as Fujitsu in Australia/New Zealand 1996-2002, manufactured by Tadiran Telecom)
  • Coral FlexiCom 200 (formerly Coral SL, discontinued)
  • Coral FlexiCom 300 (formerly Coral I, discontinued)
  • Coral FlexiCom 400 (formerly Coral II)
  • Coral FlexiCom 5000 (formerly Coral III)
  • Coral FlexiCom 6000 (formerly Coral III)
  • Coral IPx Office
  • Coral IPx 500
  • Coral IPx 800
  • Coral IPx 3000
  • Coral IPx 4000

:it:Italtel

• CT1
• CT2
• CIMA
• UT10
• UT20
• TN16
• UT100
• iMSS (Italtel Multi Service Solution), a.k.a. i-SSW

ITT Corporation

ITT Corporation

ITT Corporation is a global diversified manufacturing company based in the United States. ITT participates in global markets including water and fluids management, defense and security, and motion and flow control...

 (Includes ITT-Kellogg)

• 1210 (originally North Electric DSS)
• 1240
• TCS5
• TCS2
• TE500A
• TE400H
• TE400
• TD100
• Kellex
• 7J
• 7X2
• 7X3
• 7XB
• A1
• A1-SPC
• CRX
• CSX
• K60 (ITT-Kellogg)
• K7 (ITT-Kellogg)
• K1040
• PC32B
• Relaymatic (ITT-Kellogg)
• TCS5
• TRS4
• AN/TTC-22 100 Line Automatic/Manual Military Tactical Switch (retired)

ITT (Europe)

• 7A, 7A1, 7A2, 7E (Rotary 'machine switching' system)
• 7D (Rotary, for smaller/rural areas)
• Pentaconta (crossbar)
• Metaconta (SPC electronic)

Marconi

Marconi Communications

Marconi Communications was a principal subsidiary of the Marconi Corporation plc and was formerly known as GEC Plessey Telecommunications . The company was a world leading telecommunications manufacturer...

 (was GEC)

• System X
  System X (telephony)
  System X was the name of the UK's first national digital telephone exchange system.-Development:System X was developed by the UK Post Office , GEC, Plessey, and Standard Telephones and Cables and first shown in public in 1979 at the Telecom 79 exhibition in Geneva Switzerland...
  
  

Mitel

Mitel

Mitel Networks, is a high-tech company providing unified communications solutions for business. The company previously produced TDM PBX systems and applications but after a change in ownership in 2001 now focuses almost entirely on Voice-over-IP products.Mitel is headquartered in Ottawa,...

• SX5
• SX10
• SX20
• SX50
• SX200
• SX200D
• SX200 Light
• SX200ML/EL/ELx
• SX200ICP
• SX2000SG
• SX2000S
• SX2000 Light
• 3300ICP
• 3300MCD
• GX5000L
• GX5000S
• 5000 Communications Platform

Motorola

Motorola

Motorola, Inc. was an American multinational telecommunications company based in Schaumburg, Illinois, which was eventually divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011, after losing $4.3 billion from 2007 to 2009...

These are Mobile Telephone Switching Office

Mobile Telephone Switching Office

The Mobile Telephone Switching Office is the mobile equivalent to a PSTN Central Office. The MTSO contains the switching equipment or Mobile Switching Center for routing mobile phone calls. It also contains the equipment for controlling the cell sites that are connected to the MSC.The systems...

 Cellular switches

• EMX2500
• EMX4
• EMX5000

NEC

• Aspire
• Topaz
• C410
• C460
• NC10
• NC23
• NC23SE
• NC230
• NC460
• NA820
• NCA20
• NCX23
• ND10A
• ND10B
• ND20A
• ND20B
• ND20S
• NEAX-61 (K, L, M & S)
• NEAX-61E
  • NEAX-61E Remote
• NESXS (Nippon Electric step-by-step based on license from Western Electric)
• M100
• NEAX31 (Discrete Electronic CPU, 4-stage Crossbar switching fabric, PBX)
• NEAX22 (Analog / Digital hybrid PBX)
• NEAX 2000/1000
• NEAX2400 (Fully Digital PBX)
• XN120
• NEC Univerge SL1000 (Small or Medium Sized, VoIP And TDM)

• Enterprise IP Systems
  • NEC Univerge SV7000 (Fully IP, VoIP and TDM) Pure IP Communication server
  • NEC Univerge SV8100 (Fully IP, VoIP and TDM)
  • NEC Univerge SV8300 (Fully IP, VoIP and TDM) Pure IP Communication server
  • NEC Univerge SV8500 (Fully IP, VoIP and TDM) Pure IP Communication server

North Electric (Galion, Ohio)

• CX "All-Relay Exchanges:

(CX evolved from the "Automanual" system designed by Edward Clements "Clement eXchange" or "Community eXchange")

• • CX30 (30 line)
  • CX60 (60 line)
  • CX100 (100 line)
  • CX200 ("broadspan" up to 200 lines)
  • CX1000 (large CX expandable to 10,000 lines)
• MCX A version of the CX product line designed by F.R. McBerty after leaving Western Electric/Bell Labs and becoming President of North Electric.

The McBerty design used an early "wire spring" relay and welded piano wire interconnections rather than complex wire multiples. The system never achieved the reputation of the CX product due to problems with poor contact pressure in the interconnection relays. Despite its much lower cost of production and installation, the level of maintenance required to keep these systems on good order doomed this variation of the CX design.

• DSS1 (North's first digital switch for local exchanges)

This later was renamed the ITT 1210 product upon purchase of North electric by ITT.

• DSS2
• ETS4 (Large #4A-ETS class toll switch based on Ericsson "code switch")
• NTS4E (4-wire toll switch with Xbar switches and "Omni" processors)
• NX1 (Family NX1A, B, C & D; All based on Ericsson By-Path Crossbar license)

L.M. Ericsson purchased North Electric in the early 1950s and brought this Swedish design to North where it was reworked to conform to U.S. telecommunications requirements.

• • NX1D (Final production version)
  • NX1E (NX-1D with OMNI Processor for line/directory, trunk and number-group translation services)

The NX-1E was not a SPC switch, rather it was a conventional path controlled switching matrix with electronic processors (computers) replacing the control, route selection and translation (directory number to line ID) functions.

• NX2 (Family Small 90–1800 line CDO Xbar)
  • NX2 (Original design 1959-60)
  • NX2A (Improved cabinets ~1962)
  • UN2 Electrically and mechanically the same as the NX-2A but with design modifications specified by United Telecom (United Telecom/Sprint/Embarq) when they acquired North from L.M. Ericsson in the early 1960s. The "United" version of NX-2A replaced the intercabling connection blocks with wire wrap connections so that switches could be installed or expanded without having custom cable harnesses provided by North Electric.
  • Switcher Family (NX-2A pre-installed in a trailer for rapid installation or portable/emergency use)
    • TSW Basic Unit with growth to ~360 lines
    • TSW2 Expanded unit with growth to ~1200 lines
    • TSW3 Jumbo unit with growth to system recommended maximums
• TSD (toll switch)
• AN/TTC-20 568 Line Military Fixed Switch (Used by US Air Force - only one was known in existence at Sembach AB, Germany) (retired)
• AN/TTC-30 568 Line Military Tactical Mobile Switch (Used by US Army and Air Force) (retired)

Nortel

• Application Server 5300 (AS5300)
  Nortel Application Server 5300
  The Avaya Aura Application Server 5300 or Avaya Aura AS5300 in telecommunication and computer networking is a secure Unified Communications system designed and manufactured by Avaya...
  
  
• Business Communications Manager (BCM)
  • BCM50
  • BCM200
  • BCM400
  • BCM450
• Communication Servers (CS Systems)
  Nortel Communication Servers
  The Nortel Communication Servers is a series of products that Nortel manufactures for telephony communications. The equipment can support TDM and VoIP services for 150 users to 200,000 users or more...
  
  
  • CS1000 (22,500 lines 3200 trunks TDM and VoIP)
  • CS1500 (48,000 lines 8,400 trunks TDM and VoIP)
  • CS2000 Compact
  • CS2000 (180,000 lines 200,000 trunks TDM and VoIP)
  • CS2100
    Nortel Communication Server 2100
    The Avaya Communication Server 2100 or CS-2100 in computer networking, telecomunications and IP telephony is a carrier grade, IP soft switch or VoIP server solution for large campus and geographically dispersed large enterprises...
    
     (230,000 ports, 125,000 IP phones, 150,000 analog telephones, 125,000 digital telephones, 200,000 IP trunks, 50,025 digital trunks, 32,000 analog trunks, 200,000 SS7 trunks, 4,093 H.323 gateways, 112,000 nodes per host, 99,999 ACD agents)
• Digital Multiplex System (DMS)
  Digital Multiplex System
  Digital Multiplex System is the name shared among several different telephony product lines from Nortel Networks for wireline and wireless operators...
  
  
  • DMS-10 Carrier Class Switching System (320 ISDN PRI links or more than 20,000 lines) (First "production" class 5 digital switch installed in the North American public telephone network{fact})
  • DMS-10 RLCM (640 line remote)
  • DMS-10 RSLE (520 line remote)
  • DMS-10 RSLM (640 line remote)
  • DMS-10S (super small DMS-10 for very small exchanges, less than 640 lines)
  • DMS-10M (prepackaged DMS-10, a Community Dial Office in a pre-packaged container/"box")
• DMS-100
  Digital Multiplex System
  Digital Multiplex System is the name shared among several different telephony product lines from Nortel Networks for wireline and wireless operators...
  
   FAMILY of Digital Exchanges
  • DMS-100 (large local digital Class 5) (also known as an SL-100 when used as CPE (Customer Provided Equipment or PBX service)
    
  • DMS-100/200 (local/toll digital more than 135,000 lines)
  • DMS-200 (toll digital)
  • DMS-250 (Equal Access Carrier Switch-digital)
  • DMS-300 (International Gateway Switch-digital)
  • DMS-300/250 (combination Carrier/International Gateway 70,000 to 100,000 trunks)
  • DMS-500 (Local/Toll + CLEC Switch)
  • DMS-Global Services Platform
  • DMS-MTX (Cellular MTSO)
• Stored Program (SP) (Electronic Stored Program Control using mini-bar switches)
  • SP1 2-Wire (Local)
    • The SP1 processor was constructed using Small Scale Integration (SSI) Diode Transistor (DTL) Logic. Two types of memory was used. Processor read/write scratch memory (called CALL STORE) was implemented using a magnetic core variant called Ferrite Sheet. Program and Data Store (used to store Software and infrequently changed data) was implemented using a technology called piggy back twistor - in modern parlance a write once, read many times non-volatile memory system). As was the case with the #1ESS systems, processors and memory were duplicated with automatic comparison of processing results and automatic recovery in the event that a mismatch was discovered. It did not however support the complex recovery mechanism provided in the #1ESS where a processor from one half of the complex could be connected to a mix of memory (both call store and program store) modules from both halves of the complex in order to achieve a working combination. Processor diagnostics would generally narrow a problem down to a board or three.
    • A SP1 2-wire variant was also available that provided Centrex services.
    • A version of the SP-1 ESS that could provide both 2 & 4 wire services was also built. The first instance was installed in Vegreville Alberta in 1976 or 1977.
  • SP1 4-Wire (Toll)
    • The first example of this switch was installed for Bell Canada, in Thunder Bay, Ontario in late 1973. It provided toll services for North Western Ontario and CAMA (Centralized Message Accounting) for the City of Thunder Bay. The City of Thunder Bay which operated its own Telephone Company installed a number of 2W SP1s.
  • SP1E (used NT40 processor which was later the first processor system for the DMS-100 Family of switches)
• NE-1ESS (Northern Electric version of Western Electric) #1ESS {licensee} )
  • Bell Canada operated NE-1ESS 2 wire switches (some of which also provided Centrex services) in Toronto, Ottawa and Montreal. A 4W NE-1ESS was installed in Thunder Bay to provide telephone switching services (SAGE and AUTOVON)for USA and Canadian bases in that part of North America. The #1ESS was implemented using discrete diode transistor logic. A typical circuit board would implement a single 4 input "NAND" gate. Of the myriad of cards in the system - many were dedicated diagnostic gates. The diagnostic software had a very high (95% +) success rate identifying a single failing card. The success rate dropped quickly thereafter. Drifting Voltage Regulator cards caused a lot of angst.
• NE-4A (Northern Electric version of Western Electric) 4A toll {licensee} )
• NE-5XB (Northern Electric version of Western Electric) #5Xbar {licensee} )
• SA1 (Small Northern designed crossbar CDO)
• SA2 (Small Northern designed crossbar CDO)
• SF1 (Small Northern designed crossbar CDO)

Oki

Oki Electric Industry

, commonly referred to as OKI, OKI Electric or the OKI Group, is a Japanese company manufacturing and selling info-telecom and printer products. Headquartered in Tokyo, Japan, OKI operates in over 120 countries around the world....

• Discovery I PBX
• Discovery II PBX
• Discovery III PBX
• Discovery 8000 PBX
• D10
• D60
• D70
• KB270

Philips

Philips

Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....

• UR
• UR NB
• UR49
• URVB
• UV
• PRX/A
  PRX (telephony)
  The PRX205 is a processor controlled reed relay telephone exchange developed by Philips Telecommunicatie Industrie BV in Hilversum during the late 1960s and early 1970s. The first public switch was installed in Overvecht in Utrecht in 1972. About half of all sales were in the Netherlands...
  
  
• PRX/D
  PRX (telephony)
  The PRX205 is a processor controlled reed relay telephone exchange developed by Philips Telecommunicatie Industrie BV in Hilversum during the late 1960s and early 1970s. The first public switch was installed in Overvecht in Utrecht in 1972. About half of all sales were in the Netherlands...
  
  

REDCOM Labs

• TRANSip
• SLICE
• HDX
• IGX-A
• IGX-MT
• IGX-N
• MDX 10K
• MDX 384 modular exchange "stackable" to 384 lines/trunks

Siemens

Siemens AG

Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....

• SD50 PBX
• SD192MX PBX
• SD232 PBX
• Saturn I PBX
• Saturn II PBX
• Saturn IIE PBX
• Saturn III PBX
• No. 16 Step-by-Step
• No. 17 Step-by-Step
• No. 51 Step-by-Step
• EDX-P
• EMD55
• EMD56
• EMD57
• ESK - CP24
• ESK - CP44
• ESK - CP44A
• ESK 10000 E
• EWSD
  EWSD
  EWSD is one of the most widely installed telephone exchange systems in the world. EWSD can work as a local or tandem switch or combined local/tandem, and for landline or mobile phones...
  
  
  • Remote Switch Unit RSU-DE3
  • Remote Switch Unit RSU-DE4
  • Remote Switch Unit RSU-DE5
• RCUB-800C
• DCO-CS (Formerly Stromberg Carlson DCO) - Sold to Genband
  Genband
  GENBAND is a privately held company which makes IP multimedia application and infrastructure products and solutions for fixed wire line, mobile, and cable network service providers. The company was formed in 1999 as General Bandwidth and since 2010 is headquartered in Frisco, Texas.It has major...
  
   in 2006
• HiQ8000
• SPX2000 (Formerly Equitel)

Stromberg-Carlson

Stromberg-Carlson

Stromberg-Carlson was a telecommunications equipment and electronics manufacturing company formed in 1894 as a partnership of Alfred Stromberg and Androv Carlson. Along with four other companies, it controlled the United States national supply of telephone equipment until after World War...

• DCO 21
• DCO 80
• DCO 200
• DCO 360
• Century DCO6000
  • DCO Remote Line Switch 1000 (RLS 1000)
  • DCO Remote Line Switch 4000 (RLS 4000)
  • RLS 450
• DCO-SE
• DTM
• ESC-1 "Crossreed"
  Reed relay
  A reed relay is a type of relay that uses an electromagnet to control one or more reed switches. The contacts are of magnetic material and the electromagnet acts directly on them without requiring an armature to move them...
  
   electronic exchange
  • ESC-3
• MS30
• SC#5 (#5 Crossbar licensed from Northern Electric (Canada) for US sales/distribution)
• Motorswitch - Siemens (Germany)
• XY (Stromberg version of Ericsson "flat motion" switch operated in horizontal planes)

The DCO family starts as generic DCO

• DCO
  • DCO-E (Line Switch 10,000 lines)
  • DCO-SE (Line Switch 10,000 lines, software enhanced, class features, centrex, etc.)
    • DCO-RLS (Remote Line Switch, controlled by hosts above)
      • RLS 1000 (Pedestal mount cabinet 1000 lines in a subdivision - required multiple T-1's to host)
      • RLS 4000 (Same thing, but 4000 lines)
      • RLS (This has the ability in a host outage to make intra-cabinet calls)
      • The line switches will also talk to AT&T SLC-96 pedestals - 96 lines on a ped
  • DCO-CS (Long distance, very limited lines - 1+ trunking to long distance all T-1 cards)

Note: DCO systems are now supported by GENBAND

Genband

GENBAND is a privately held company which makes IP multimedia application and infrastructure products and solutions for fixed wire line, mobile, and cable network service providers. The company was formed in 1999 as General Bandwidth and since 2010 is headquartered in Frisco, Texas.It has major...

Tadiran Telecom

Tadiran Telecom

Tadiran Telecom Ltd is a telecommunications company which offers enterprises complete converged communications solutions that support voice, data, video and advanced applications. It is represented by a global network of more than 200 distributors and affiliates in 40 countries.The corporate...

• Coral FlexiCom 200 (formerly Coral SL, discontinued)
• Coral FlexiCom 300 (formerly Coral I, discontinued)
• Coral FlexiCom 400 (formerly Coral II)
• Coral FlexiCom 5000 (formerly Coral III)
• Coral FlexiCom 6000 (formerly Coral III)
• Coral IPx Office
• Coral IPx 500
• Coral IPx 800
• Coral IPx 3000
• Coral IPx 4000
• Coral ICE
• Coral Sea Soft Switch

Tekelec

Tekelec

Tekelec, Inc. is a US company , founded 1971 in California, but now headquartered in Morrisville, North Carolina. Tekelec produces hardware and software solutions for telecoms - land line, mobile and data.-Jean-Claude Asscher:...

• Tekelec 9000 Distributed Switching Solution (formerly SanteraOne)
• Tekelec 7000 Class 5 Packet Switch (formerly Taqua Open Compact Exchange)

Tropico

• Tropico C (Subscriber Line Digital Concentrator)
• Tropico R (Small Capacity Local/Tandem Exchange)
• Tropico RA (Local/Transit Exchange)

VEB Kombinat Nachrichtenelektronik

• DVZ 2000 (space-division digital switch)
• ENSAD (time-division digital switch)
• OZ 100 D (96-line time-division digital switch)

Panel

Panel switch

The panel switching system was an early type of automatic telephone exchange, first put into urban service by the Bell System in the 1920s and removed during the 1970s...

• Local Panel
  • Battery cut-off (BCO)
  • Ground cut-off (GCO)
• Panel Tandem
  • Panel Sender Tandem
  • Office Select Tandem

Step-by-Step

Stepping switch

In electrical controls, a stepping switch, also known as a stepping relay, is an electromechanical device which allows an input connection to be connected to one of a number of possible output connections, under the control of a series of electrical pulses. It can step on one axis , or on two axes...

 / Strowger

Strowger switch

The Strowger switch, also known as Step-by-Step or SXS, is an early electromechanical telephone switching system invented by Almon Brown Strowger...

• No. 1
• No. 350A
• No. 355A CDO (Community Dial Office)
• No. 356A
• No. 360A

Crossbar switch

Crossbar switch

In electronics, a crossbar switch is a switch connecting multiple inputs to multiple outputs in a matrix manner....

• Crossbar Tandem
• No. 1 Crossbar
• No. 3 Crossbar
  • No. 3 Crossbar 2-Wire
  • No. 3 Crossbar 4-Wire
• No. 4 Crossbar
  • No. 4A/CTS Crossbar (Card Translator System)
  • No. 4A/ETS Crossbar (Electronic Translator System)
  • No. 4M Crossbar
  • No. 4M ETS Crossbar
• No. 5 Crossbar
  • No. 5 Crossbar 2-Wire
  • No. 5 Crossbar 4-Wire
  • No. 5 ETS Crossbar
  • No. 5A Crossbar

Electronic Switching System

Electronic switching system

In telecommunications, an electronic switching system is:* A telephone exchange based on the principles of time-division multiplexing of digitized analog signals. An electronic switching system digitizes analog signals from subscriber loops, and interconnects them by assigning the digitized...

 SPC

• ESS (Experimental system installed in Morris, Illinois
  Morris, Illinois
  Morris is a city in Grundy County, Illinois, United States. The population was 13,636 at the 2010 census.Morris is home to the Dresden Nuclear Power Plant, which provides a substantial portion of the electricity supply for the Chicago metropolitan area...
  
  . In operation November 1960–?. This switch was never given a name other than "Morris ESS".)
• No. 101 ESS
• No. 1 ESS (1ESS)
  1ESS switch
  The Number One Electronic Switching System, the first large-scale Stored Program Control telephone exchange or Electronic Switching System in the Bell System, was introduced in Succasunna, New Jersey, in May 1965. The switching fabric was composed of reed matrixes controlled by wire spring relays...
  
  
  • No. 1 ESS 2-Wire
  • No. 1 ESS 4-Wire
• No. 1A ESS
• No. 2 ESS (2ESS)
  • No. 2A ESS
  • No. 2B ESS
  • No. 2C ESS
• No. 3 ESS (3ESS)

Electronic Switching System

Electronic switching system

In telecommunications, an electronic switching system is:* A telephone exchange based on the principles of time-division multiplexing of digitized analog signals. An electronic switching system digitizes analog signals from subscriber loops, and interconnects them by assigning the digitized...

 TDM

• No. 4 ESS (4ESS
  4ESS switch
  The 4ESS switch is a Class 4 telephone Electronic Switching System that was the first digital electronic toll switch introduced by Western Electric for long distance switching. It was introduced in 1976 in Chicago, Illinois to replace the 4a crossbar switch. The last of 145 in the AT&T network was...
  
  )
• No. 5 ESS (5ESS
  5ESS Switch
  The 5ESS Switch is a Class 5 telephone electronic switching system sold by Alcatel-Lucent. This digital central office telephone circuit switching system is used by many telecommunications service providers.-History:...
  
  )
  • No. 5 ESS CDX (Compact Digital Exchange)
  • No. 5 ESS-2000 VCDX (Very Compact Digital Exchange)
  • No. 5 ESS-2000 VCDX Remote
  • No. 5A RMS (Remote Switching Module)
  • No. 5B RMS (Remote Switching Module)
  • No. 5E XC (Extended Capabilities)
• No. 7 R/E (Revolutionary/Evolutionary)
• No. 10A Remote Switching System (10A RSS)

Other digital switches

• BZ5000 (formerly Batik Elcom 4KT from Batik/Zetax, Brazil)
• CSD
• iGen
• PacketStar PSAX1000/1250/2300/4500
• Plexus/Lucent Gateway Platform/Lucent Compact Switch (formerly Telica Plexus 9000)
• Zetax ZTX610

USSR manufacturers

• AMTS-1M
• AMTS-2
• AMTS-3
• Кварц (Quartz)
• M-10C
• ATS-47
• ATS-54
• ATS-K
• ATS-K4
• ATSK-U