Abstract: A virtual chassis system includes a plurality of network nodes configured with a master virtual chassis address. The network nodes are connected by virtual fabric link (VFLs) that provide a connection for exchange of packets between the network nodes. The packets include source MAC addresses and associated hardware device information, such as source chassis ID, source network interface identifier and source port identifier information. The network nodes use this information to maintain synchronized MAC address tables for forwarding of packets in the virtual chassis system.

Abstract: A virtual chassis system includes a plurality of network nodes configured with a master virtual chassis address. The network nodes are connected by virtual fabric link (VFLs) that provide a connection for exchange of packets between the network nodes. The packets include source MAC addresses and associated hardware device information, such as source chassis ID, source network interface identifier and source port identifier information. The network nodes use this information to maintain synchronized MAC address tables for forwarding of packets in the virtual chassis system.

Abstract: In a computerized tomographic apparatus, different detectors are caused to receive radiation along substantially the same beam path through the body in order to permit the evaluation of differences in performance of the detectors. This evaluation is average with other evaluations made in respect of the same detector for other beam paths so as to reduce the risk that erroneous performance differences may be evaluated in the event that any of the relevant beam paths lies adjacent a bone edge in a patient's body. Also disclosed are techniques for electronically deflecting the radiation so that part at least of the radiation is taken clear of the body and can be detected to provide reference signals.