| 摘要 |
A high speed communication link between peripheral nodes and a single multi-link layer protocol (MLAP) controller with an integrated HDLC framer in a main control complex. Peripheral nodes contain a very simple control that forwards all the HDLC D-channel data from the peripherals to a single MLAP controller, thus making the peripheral nodes small in physical size, extremely flexible to connect to new interfaces and very portable. Accordingly it facilitates the efficient distributed deployment of the PABX. Using the described system, the PABX itself may be distributed around a building, using a backbone high speed link. Peripheral nodes may be located at various places in a building with peripherals such as line interfaces and associated digital telephones at locations as needed. They need not be centralized, adjacent the main control complex, as is now required. This facilitates the provision of a building with a flexible communication system having substantially reduced wiring requirements. The bit rate of transmission of HDLC formatted data is changed from 16 kb/s or 64 kb/s to 2.048 mb/s and visa versa. Plural modified HDLC packets are multiplexed to one physical link that is terminated by an HDLC framer inside the multi-link access protocol controller or, from one MLAP controller, many peripherals can be accessed and controlled. The functions of the present invention are transparent to the end-point HDLC framers and hence to the link layer protocol and peripheral software.
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