Method and apparatus for rendering a cell-based switch useful for frame based protocols

A method for adapting to different data rates between an input data frame and a cell-based switch fabric within a data switch, the switch fabric having fixed-sized cells each having a data payload, the method comprising:

• a) receiving a first portion of the data frame at an input port;
• b) establishing a path through the cell-based switch fabric to a destination port selected by examining a destination address found in the first portion of the data frame;
• c) sending a first data cell containing at least part of the first portion of the data frame across the path;
• d) after sending the first data cell, receiving a second portion of the data frame;
• e) partially filling the data payload of a second data cell with the second portion of the data frame;
• f) sending the second data cell across the path even though the data payload of the second data cell is not filled;
• g) detecting an end of the data frame;
• h) after detecting the end of the data frame, sending an End of Packet indicator across the data path to the destination port;
• and
• i) closing the path through the cell-based switch fabric when the End of Packet indicator has been detected at the destination port.

A data switch comprising:

• a) a cell based switch fabric using fixed size data cells;
• b) an input port having logic to:
• i) receive a data frame,
• ii) establish a path across the cell-based switch fabric,
• iii) partition the data frame into data cells to be sent across the path, with at least two data cells having a partially filled and partially empty cell payload and with a third data cell having an end-of-packet indicator to inform the output port that the entire data frame has been sent across the path;
• and
• c) an output port having logic to:
• i) receive the data cells across the path, and ii) terminate the path upon receipt of the end-of-packet indicator.