Abstract: An apparatus consisting of a digital communication channel comprised of a multiplicity of lanes where data is striped across the lanes in a predefined sequence. Each lane has the ability to be powered down or powered up in response to the amount of data being held in a transmit buffer at one end of the communication channel. The method consists of monitoring the amount of data being held in the transmit buffer; making the decision of how many lanes are required based on the amount of data; sending signals to cause the required number of lanes to be powered down or powered up; and performing the required power down or power up action at the particular transmitter and receiver.

Abstract: An autoprotected optical communication ring network includes a first and a second optical carrier (2, 3) having opposite transmission directions and a plurality of optically reconfigurable nodes (20a-20f) optically connected along the first and the second optical carrier (2, 3) and adapted to communicate in pairs by means of respective links susceptible of failure, the ring network having a normal operative condition in which the nodes of each pair are optically configured so as to exchange optical signals on a respective working arc path at a respective first wavelength (&lgr;x) on the first carrier (2) and at a respective second wavelength (&lgr;y) different from the first wavelength (&lgr;x) on the second carrier (3), the respective working path having a complementary arc path defining a respective protection arc path in which the first wavelength (&lgr;x) on the first carrier (2) and the second wavelength (&lgr;y) on the second carrier (3) can be used for further links and the first wavelength (&lgr;x) on

Abstract: A hierarchical wide-area network architecture which conforms to the DLSw protocol is provided, in which multiple routers having a logical connection to one another are designated as a peer group. At least one router in each peer group is designated as a border peer, and functions as a gateway between the members of its group and other peer groups. The peer group structure reduces broadcast traffic on slow links by changing the source of the broadcast from a small access router with a relatively slow link to another, more powerful router, with a faster link on the network. More than one border peer can be included in each group, to share the transmission workload and act as a backup. The border peers can share information about the groups that they service and can cooperate to provide a single-point broadcast service to all of the users of the service. When two or more routers are connected to a network in parallel to provide back-up facilities, conditional filters are employed to prevent redundant operations.