telephone exchange definition of telephone exchange in the Free Online Encyclopedia.

central office

A local telephone company switching center. There are two types of central offices (COs). The first is called an "end office" (EO) or "local exchange" (LE) and connects directly to the outside plant, which is the feeder and distribution system to homes and offices. The end office (often called a "Class 5 office") provides customer services such as call waiting and call forwarding.

Tandem/Toll Office
The second type is the tandem office (also toll office or tandem/toll office), which is a central office that does not connect directly to the customer. Toll call record generation and accounting used to be handled in the tandem offices. Today, the billing is mostly done in the end offices. There are more than 25,000 central offices in the U.S. See LEC, IXC and LATA.

Central Offices

End offices provide the local loops directly to customers, while tandem offices carry traffic between end offices. The PSTN is made up of local exchange carriers (LECs) and interexchange carriers (IXCs) that are governed by LATA boundaries.

High-Tech Switching in the 19th Century

This "central office" was used to switch phone calls between all the lawyers in Richmond, Virginia in 1882. (Image courtesy of AT&T.)

central office [′sen·trəl ′ȯ·fəs]

(communications)

A switching unit, installed in a telephone system serving the general public, having the necessary equipment and operating arrangements for terminating and interconnecting lines and trunks. Also known as telephone central office.

(communications)

central office - The place where telephone companies terminate customer lines and locate switching equipment to interconnect those lines with other networks.

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No references found	With reliability comes cost - maintaining old style land lines, and then inter office telephone exchange systems represents a significant amount of hardware infrastructure and expense, and as anyone who''s had to upgrade a legacy phone exchange can tell you, sometimes, those old standards are difficult or even impossible to maintain. The Benefits of IP Telephony for Your Business by Navjot Kaur / Computers and Internet community WANA, September 03, 2009 (Balochistan Times): The Taliban militants have taken control of telephone exchange in South Waziristan, suspending the agency communication with whole world including Pakistan. Taliban take control of telephone exchange in S. Waziristan by Balochistan Times (Baluchistan Province, Pakistan) WANA, September 03, 2009 (Frontier Star): The Taliban militants have taken control of telephone exchange in South Waziristan, suspending the agency communication with whole world including Pakistan. Taliban take control of telephone exchange in S. Waziristan by The Frontier Star (Northwest Frontier Province, Pakistan)	Telenka Telenomus teleological ethics Teleology teleoperation teleoperator Teleorman Teleosauridae Teleostei TELEPAC telepathy Telephone Telephone Answering Device Telephone Application Program Interface telephone booth telephone booth-stuffing Telephone Cable telephone carrier current Telephone Central Office telephone channel telephone circuit Telephone Communication telephone data set telephone dial telephone emission telephone exchange telephone induction coil telephone influence factor telephone line telephone loading coil telephone modem Telephone Network telephone pickup telephone plug Telephone Receiver Telephone Register Telephone Relay telephone repeater telephone repeating coil telephone ringer Telephone Set telephone signal telephone station telephone switch Telephone Switchboard telephone system telephone theory Telephone Traffic telephone transmitter telephone-answering system Telephony	Telephone Conversation Confirmation Telephone Conversation Record Telephone Conversation With Telephone Conversation/Conference telephone cord telephone cord Telephone counseling Telephone counselling Telephone Country Code Telephone Crime Reporting Unit telephone data set Telephone Database Integration Telephone Device for the Hearing Impaired telephone dial telephone dial Telephone directories telephone directory telephone directory Telephone Directory Monitor Telephone Disclosure and Dispute Resolution Act Telephone Emergency Notification System Telephone Emergency Services telephone emission Telephone Employees Flying Club, Inc. Telephone Entry and Reporting System Telephone Equipment Network Telephone Equipment Order telephone exchange Telephone Exchange Crossbar Telephone eXchange Electronics Telephone EXchange Name Project Telephone eXchange Strowger Telephone exchanges Telephone Excise Tax Refund telephone extension telephone extension Telephone Extension Alert Telephone Extension Hold Music Activator telephone f.-u. telephone f.-u. telephone f.-u. telephone follow-up Telephone Free Landslide Victory Telephone hacking Telephone hacking Telephone Handset Audio Tap Telephone Health Advisory Service Telephone Help Line telephone in telephone induction coil Telephone Industries of Pakistan Ltd. telephone influence factor Telephone Information Briefing Service Telephone Information Center Telephone Information Directory Telephone Information Management System

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References in periodicals archive

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With reliability comes cost - maintaining old style land lines, and then inter office telephone exchange systems represents a significant amount of hardware infrastructure and expense, and as anyone who''s had to upgrade a legacy phone exchange can tell you, sometimes, those old standards are difficult or even impossible to maintain.

The Benefits of IP Telephony for Your Business by Navjot Kaur / Computers and Internet community

WANA, September 03, 2009 (Balochistan Times): The Taliban militants have taken control of telephone exchange in South Waziristan, suspending the agency communication with whole world including Pakistan.

Taliban take control of telephone exchange in S. Waziristan by Balochistan Times (Baluchistan Province, Pakistan)

WANA, September 03, 2009 (Frontier Star): The Taliban militants have taken control of telephone exchange in South Waziristan, suspending the agency communication with whole world including Pakistan.

Taliban take control of telephone exchange in S. Waziristan by The Frontier Star (Northwest Frontier Province, Pakistan)