5ESS - switching system, universal digital telephone exchange with distributed control. Refers to a Class-5 automatic telephone exchange (telephone network node serving subscribers directly). The entire range of functions of the 5ESS system is implemented in only three types of modules: administrative AM, communication CM and switching SM. Each module consists of many microprocessors, the communication between which is carried out using an internal digital network that combines all the modules of the system.
Developed in 1982 by Lucent Technologies , a former AT&T [1] . 5ESS-2000 is an improved version of 5ESS, delivered in three different configurations: DCS, CDX, VCDX [1] .
Content
- 1 History
- 2 General architecture and main technical parameters of the system
- 3 notes
- 4 Literature
- 5 Links
History
The 5ESS electronic digital switching system was developed by AT & T Corporation. It is used quite widely on rural, urban, intercity, international and cellular telephone networks.
General architecture and basic technical parameters of the system
The AM administrative module performs system-wide functions, serves to store and administer the database, centralized technical operation and maintenance of the station, participates in complex call routing, and also performs a number of functions not directly related to the call processing process. With the help of AM, the station is diagnosed, identification, localization and, if possible, troubleshooting are performed. Through AM, access is made to recording and reading devices from magnetic media, and access to disk drives. Also, charging data is accumulated in this module. Through AM, station staff can use the terminal to provide both local and remote access to any station systems. Through AM, 5ESS is connected to automated systems for technical operation and maintenance and a traffic management system. There are data transmission channels for connecting to technical operation centers or tariffication data processing centers. Files are transferred using the standard FTAM access control and transmission protocol. The AM module is based on the 3B21D processor developed at Bell Lab, which provides high fault tolerance.
The CM communication module (or communication module) carries out spatial switching of voice channels between switching modules and packet switching of control messages between the processors of CM and AM switching modules. In addition, the CM provides 5ESS station synchronization. The main elements of CM are: spatial switching matrix, message switch, packet switch, and integrated clock source. For communication in CM fiber optic intermodular connections are used.
The SM Switch Module provides basic call service features. Call processing in the station is 98% performed by switching modules. Up to 5120 subscriber (AL) or 500 trunk (SL) lines, or a combination of AL and SL in the specified range, can be connected to each SM module. The SM Switch Module is the primary unit for increasing system capacity. One 5ESS digital switching system can contain up to 192 SM modules and serve up to 350 thousand ALs or 90 thousand SLs, as well as any combination of them. The maximum capacity of the system is limited by a capacity of 45 thousand erlang or 900 thousand calls per hour of maximum load .
Notes
- ↑ 1 2 Dong, 2007 .
Literature
- Jielin Dong. Network Dictionary. - Javvin Technologies Inc., 2007. - P. 7-8. - ISBN 978-1-60267-000-6 .
- Rudolf J. Frank: AT & T's Long Distance Runner // Black Enterprise. - Earl G. Graves, Ltd., 1988. - Vol. 18, No. 7 . - P. 96. - ISSN 0006-4165 .
Links
- Switch Basics 5ESS Scribd.com