A switch queue predictive protocol (SQPP) includes a packet switching system
including:
a switch fabric having a cross-point switch, and a plurality of line cards, each
coupled to the switch fabric. A cross-point buffer is located at each cross-point
of the cross-point switch. The switch fabric also includes a plurality of actual
available queue space tables (AAQSTs), each identifying the actual queue space
available in a row of the cross-point buffers. Each of the line cards includes
an input buffer, an output buffer, and a predicted available queue space table
(PAQST) identifying predicted queue space available in a corresponding row of the
cross-point buffers. Packet information is transmitted from a source line card
to the switch fabric only if available queue space is predicted by the corresponding
PAQST. The switch fabric uses the AAQST to update the PAQST after packet information
is transmitted to a destination line card.