Patent ID: 6684258
Filing Date: 2004-01-27
Classification: H04L

Abstract:
A network unit for sending and receiving data packets and connectable in a ring with other similar units, the network unit having:a master mode, wherein it can place packets on the ring and arbitrate in response to requests for mastership in packets received from the ring to determine whether to retain or relinquish mastership; and a repeat mode, wherein the network unit can forward on the ring packets received by way of the ring but is not permitted to place packets on the ring, and wherein the network unit is permitted to insert a request for transfer of mastership in a packet and in response to a packet denoting a transfer of mastership to the network unit to change from the repeat mode to the master mode; wherein the network unit in said master mode is operative to send, after an arbitration packet into which a request for transfer of mastership can be inserted by another unit, and before said arbitration packet returns to said network unit by way of said ring, at least one further data packet and said at least one further data packet has a header which prevents other units from inserting said requests for transfer of the mastership of the ring.