Abstract: Vehicles such as airliners or trains can be equipped with a form of local area network in which individual network connections are made to individual passenger seats using standard telephony connectors. Passengers having computers can connect to the network using their own conventional telephone cables. Wireless communications technology is used to link the vehicle network to external ground stations or satellite systems. To meet the DC power requirements of mobile computer users, the vehicle includes a DC power source. A normally unused wire-pair in the telephony connectors brings the DC power to each seatback. A slightly modified connector is used to transfer the DC power to the computer's DC power subsystem.

Abstract: A hardware function performed in the data link control layer first determines if a received frame is an IP frame requiring IPSec processing, and if it is, places the IPSec frame on a separate receive queue for subsequent inbound processing. The hardware function further determines if a frame to be transmitted is an IP frame requiring IPSec outbound processing, and if it is, places the IPSec frame on a separate transmit queue for subsequent outbound processing. To determine if an IP frame is an IPSec frame, the hardware function examines both the type field in the Medium Access Control (MAC) header and the protocol field in the IP header, both at the data link control layer. Once IPSec and non-IPSec traffic are separated at the data link layer into different receive or transmit queues, a hardware assist component processes the IPSec data frames in parallel with the processing of non-IPSec data frames by the processor in the network device.

Abstract: A converged service frame format is defined to support any-to-any connections between Ethernet and Token Ring LANs. The converged service frame format is a superset of standard Ethernet frame formats defined in IEEE 802.3 specifications. Where the frame source is an Ethernet LAN, an 802.1Q tag is added. Where the frame source is a Token Ring LAN, other operations are performed, including mapping of Token Ring priority bits into an appropriate field in the converged service frame. The operations required to map either an Ethernet or a Token Ring frame into the converged service frame are performed at an edge device at a point of ingress into an intervening network. The inverse operations required to restore the Ethernet or Token Ring frame are similarly performed in an edge device at a point of egress from the network.

Abstract: A programmable multispeed communication apparatus includes a plurality of identical media access control (MAC) units for use with a programmable data processing system. The MAC units when multiplexed and connected to a communication media achieve a transmission speed n·s where n is the number of MAC units and s is the speed of the individual MACs. If one or more but not all of the MAC units fail, the apparatus will operate in degraded mode with the remaining active MAC units. User frames are sequentially numbered, partitioned into sequentially numbered partitions which are assigned to one or more MAC's. Each of the partitions includes a prefix which includes the sequential frame number, the sequential partition number and an indicator for distinguishing the last partition of a frame from the other partitions of that frame.