| 摘要 |
<p>This invention provides a high-speed link switch (132) for a distributed-control burst-switching communications system. The switch provides fully integrated voice and data services. A communications system employing the invention includes a plurality of switches interconnected by time-division multiplexed links. In a preferred embodiment, a link switch comprises a central memory (160) coupled with a link-input processor (140), a link-output processor (162), a port-input processor (168), a port-output processor (170), and a memory manager (172). The link switch includes switching intelligence for routing a burst through the switch toward its destination port in the system. A burst is a plurality of bytes which may represent, for example, a block of data or a spurt of voice energy as sensed by silence/voice detectors located at voice ports. Within an outgoing communications link, a burst is transmitted by the switch one byte at a time in an assigned channel of sequential frames of the time-division multiplexed link. A byte is a predetermined number of bits, preferably eight bits, equivalent to the transmission capacity within a channel. The routing intelligence employs dynamic allocation of bursts to channels within communications links such that any channel of a communications link is allocated only when a burst is being transmitted therein and such channel is otherwise available for transmission of another burst. A preassigned terminator character is used to signal the end of a burst, and a data-link escape character-insertion method is employed to distinguish a data character having the terminator's bit configuration from the terminator itself. In an alternate embodiment of the invention, a multiplexer is coupled between the port processors and the external port circuits (178). A link switch as disclosed herein will meet the growing communications needs of the present and foreseeable future. </p> |
