Method and apparatus for accumulating and distributing data items within a packet switching system

This invention relates to accumulating and distributing data-items within a packet switching system, and more particularly, the invention to communicating flow control information within a packet switching system. Methods and apparatus are disclosed for accumulating and distributing information in a packet switching system. For example, it is desirable in certain packet switching systems to communicate the status of internal queues and other port status information from an individual port to all other ports (or at least those which are communicating with the individual port). The amount of information being sent from the individual port is typically very small, such as on the order of a few bits or bytes. By accumulating the information and then broadcasting the collected flow control information, a vast amount of switch fabric resources (e.g., bandwidth) can be saved. In one implementation, flow control information is sent to a destination (e.g., a "mailbox") within a packet switching fabric which includes a memory in which flow control information is accumulated. After a period of time or based on the occurrence of some event, the accumulated flow control information is distributed. This same mechanism may be used to distribute most any type of information (e.g., flow control information, signaling information, and data internal or external to a packet switch or packet switching system).