Hardware Components
A telephone exchange's hardware consists of call-path, control, and input/output components.
- The call-path section sends and receives telephone signals, monitors circuit status, and establishes connections. It mainly includes subscriber circuits, trunk circuits, the switching network, service circuits (including digit receivers, digit senders, ring generators, ringback-tone generators and connectors), scanners and drivers.
- The control section runs programs, processes data and issues control commands. Its main components are the processor and main memory.
- The input/output section provides the human-machine interfaces needed for maintenance and management. It mainly includes external storage, a keyboard, a display and a printer.
Software Components
The software consists of program and data components.
- The program component includes the operating system and applications. The operating system handles task scheduling, input/output control, fault detection and recovery, fault diagnosis, and command execution. Applications handle telephone events and state processing, hardware-resource management, subscriber-service categories, traffic statistics, service observation, software maintenance and automatic testing.
- The data component includes system data, switching-framework data, exchange data, routing data and subscriber data. It describes the characteristics of the switching system, the telephone office and its surrounding environment, and the service categories assigned to subscribers.
Current program-controlled telephone exchanges are mainly analog or digital. Their principal differences include:
- Compared with analog program-controlled exchanges, digital exchanges support longer call distances, faster transmission, clearer voice quality and fewer transmission errors.
- A digital exchange provides a non-blocking switching path. Analog exchanges have a limit on available paths; an exchange with less capacity has fewer call paths.
- Digital exchanges offer a wider range of interfaces. They can connect loop trunks, carrier trunks, E/M interfaces, 2 Mbit/s trunks and digital subscriber interfaces such as 2B+D and 30B+D, and support networking and tandem switching. For example, connecting a 2 Mbit/s trunk can turn the exchange into a virtual network. The source says these capabilities cannot be matched by analog exchanges.
Functions
- Improve telephone use by assigning an extension to each office position, so callers can reach the relevant person directly.
- Provide a computerized attendant and voice prompts, allowing callers to dial an extension directly and helping save time and improve office efficiency.
- Control extension permissions to help reduce telephone costs.
- Some models can be controlled from a PC in real time and provide live call-record queries, which the source notes may suit hotels, guesthouses and inns.
- Automatically use least-cost routing for domestic and international IP long-distance calls.
- Provide a manager-secretary function to screen unwanted calls.
In summary, Yuqi Intelligent has extensive experience in telephone-exchange system design and implementation. For questions or requirements related to telephone exchanges, contact Lanmeng for consultation and support.