Packet switching system for forwarding packets from input buffers using idle/busy status of output buffers

A packet switching system comprising:

• N input buffers connected respectively to N incoming links where N is an integer greater than one;
• N output buffers connected respectively to N outgoing links;
• a self-routing network connected between said input buffers and said output buffers for routing packets from the input buffers to the output buffers according to routing information contained in the packets;
• N output controllers associated respectively with said output buffers, each of the output controllers determining an idle space of the associated output buffer which is available for storing additional packets and determining whether the idle space is greater than N, and generating an idle status bit if the idle space is determined to be greater than N or a busy status bit if the idle space is determined to be smaller than N;
• and
• N input controllers associated respectively with said input buffers, each of the input controllers including memory means for storing said idle status bit and said busy status bit from said output controllers, and means for writing an incoming packet into the associated input buffer and reading the incoming packet therefrom into the self-routing network if an idle status bit is stored in said memory means corresponding to the routing information of said incoming packet.

A packet switching system comprising:

• a plurality of input buffers connected respectively to a plurality of incoming links;
• a plurality of output buffers connected respectively to a plurality of outgoing links;
• a self-routing network connected between said input buffers and said output buffers for routing packets from the input buffers to the output buffers according to routing information contained in the packets;
• a plurality of output controllers associated respectively with said output buffers, each of the output controllers determining an idle space of the associated output buffer which is available for storing additional point-to-point packets and additional multicast packets, determining whether the idle space of point-to-point packets is greater than a first predetermined value, determining whether the idle space of multicast packets is greater than a second predetermined value smaller than said first predetermined value, generating a first idle status bit or a first busy status bit if the idle space is determined to be greater or smaller than said first predetermined value, respectively, and generating a second idle status bit or a second busy status bit if the idle space is determined to be greater or smaller than said second predetermined value, respectively;
• and
• a plurality of input controllers associated respectively with said input buffers, each of the input controllers including memory means for storing said first idle and busy status bits and second idle and busy status bits from said output controllers, and means for writing an incoming point-to-point packet into the associated input buffer and reading the incoming point-to-point packet therefrom onto the self-routing network if a first idle bit from is stored in said memory means corresponding to the routing information of the incoming point-to-point packet, storing an incoming multicast packet into the associated input buffer and reading the incoming multicast packet therefrom onto the self-routing network if a second idle status bit is stored in said memory means corresponding to the incoming multicast packet.

A packet switching system comprising:

• N input buffers connected respectively to N incoming links where N is an integer greater than one;
• N output buffers connected respectively to N outgoing links;
• a self-routing network connected between said input buffers and said output buffers for routing packets from the input buffers to the output buffers according to routing information contained in the packets;
• N output controllers associated respectively with said output buffers, each of the output controllers determining an idle space of the associated output buffer which is available for storing additional point-to-point packets and additional multicast packets, determining whether the idle space of point-to-point packets is greater than M which is an integer greater than N and whether the idle space of multicast packets is greater than N, generating a first idle status bit or a first busy status bit i the idle space is determined to be greater or smaller than M, respectively, and generating a second idle status bit or a second busy status bit if the idle space is determined to be greater or smaller than N, respectively;
• and
• N input controllers associated respectively with said input buffers, each of the input controllers including memory means for storing the first idle and busy status bits and the second idle and busy status bits from said output controllers, and means for writing an incoming point-to-point packet into the associated input buffer and reading the incoming point-to-point packet therefrom onto the self-routing network if a first idle status bit is stored in said memory means corresponding to the routing information of the incoming point-to-point packet, writing an incoming multicast packet therefrom onto the self-routing network if a second idle status bit is stored in said memory means corresponding to the incoming multicast packet.