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Architecture : The C-DOT switches have a distributed architecture.A base module (BM) has 512 portswhich can provide non-blocking connectivity and can accept concentrated subscriber lines.The BM capable of serving 2000 linesor 512 trunks, is used as a basic building block. Each BM is housed in a single cabinet. By interconnecting Module (CM), the switch can support upto 40000 lines. The system can support upto 4:1 concentration. Lines and trunks can be inter-mixed in the same BM.

The front-end of the system consists of an input-output processor (IOP) connected to the Administration processor (AP). Each system consists of two IOPs working in duplex mode. IOP, based on Motorola 68010 and suppporting UNIX environment, provides interface for the main machinecommunication, system initialisation support, operator features etc.

The switch is capable of local, trunk, and integrated-local-cum-Transit applications.It is meant to provide cost-effective solution for metropolitan needs. There is commanality of hardware, software, features and facilities, packaging, operations and maintenanc, etc. in all MAXs.

Hardware : A BM can support upto 16 Terminal Units (Tus), each handling 128 terminations. A service Unit (SU) caters for the service functions like tone generation. MF/DTMF signalling etc. The switch is controlled by Motorola 68000. In the periphery one 8-bit microprocessor controls 128 terminations. The system has a high redundancy - all hardware excluding the line/trunk terminations are duplicated to provide a very high system reliablity. The switch uses less than 40 card types. The controllers communicate through a Base Message Switch (BMS) via 64 Kb/s HDLC links. The switch is highly connectorised with minimal inter-frame wiring. Low power CMOS tecnology ensures low power consumption. The BM is convection cooled and the CM is forced-air cooled.

The major function of CM is to provide voice switching between the BMs and enable communication of control messages between different parts of the system The Ap supports the global routing and translation functions.

Software : The software is distributed across the 16-bit and 8-bit controllers of the system. Majority of the software real time functonsare handled at the BM level. Only minimal real time functions are handled at the AP. The BP handles call processing, administration, and maintenance functions relating to the terminations connected to that BM. Majority of the real time software runs under a custom built real time operating system called CDOS. The software is implemented as modular communicating processes using 'C' language.  

[ Technical Specifications ]