Patent ID: 6330245
Filing Date: 2001-12-11
Classification: H04L

Abstract:
A data network hub comprising a plurality of hub units each connected to supply data packets to network data destinations and receive data packets from network data sources, said hub including a closed data transmission ring which enables packets received at any unit to be transmitted from any other unit and wherein:(i) each hub unit includes means for supplying data to said ring and for receiving data from the ring and means for controlling access to the ring for the supplying of packets to(ii) a unit which is acting as a master unit, supplying packets to the ring, replaces fields in the headers of said packets with arbitration fields, said arbitration fields including a request field and a grant field,(iii) the master unit responds, when it has no more packets to supply to the ring and it receives by way of said ring a packet header which has a request field set, to set said grant field;(iv) a unit which is not the master and has data to place on the ring responds to a packet header received by way of said ring to modify the header to set a request field; and(v) a unit which is not the master and has data to place on the ring responds to a packet header which has the grant field set to become the master unit to provide data packets to said ring.