摘要:
A drilling system for use at a wellhead has a plurality of modules each containing rig component equipment. The plurality of modules are connected or interconnected together so as to form a drilling rig. Each of the plurality of modules has a size adapted to be lifted by forklift or a front end loader. The plurality of modules are arranged such that one end of the plurality of modules is adjacent to the wellhead. A pipe handling system is positioned adjacent to one end of the plurality of modules. A ventilation system is cooperative with the plurality of modules so as to move air toward or away from heat-generating equipment in the plurality of modules.
摘要:
Deciphering and verification of the checksum of enciphered and encapsulated UDP datagrams, particularly those which enclose a tunneling protocol such as L2TP, are achieved by the provision of a checksum verifier in parallel with a decipher block. Checksum logic creates a pseudo UDP header needed for checksum verification using fields that would occur at the start of the packet that encapsulates the UDP datagram. The first part of the packet to be deciphered is the UDP header; checksum logic can latch the checksum field into a local register. As the rest of the packet is deciphered the checksum verifier processes the data at the same time. Eventually the checksum logic will acquire a complete checksum which can be compared with the checksum that had been previously latched, so as to verify the checksum.
摘要:
Deciphering and verification of the checksum of enciphered and encapsulated UDP datagrams, particularly those which enclose a tunnelling protocol such as L2TP, are achieved by the provision of a checksum verifier in parallel with a decipher block. Checksum logic creates a pseudo UDP header needed for checksum verification using fields that would occur at the start of the packet that encapsulates the UDP datagram. The first part of the packet to be deciphered is the UDP header; checksum logic can latch the checksum field into a local register. As the rest of the packet is deciphered the checksum verifier processes the data at the same time. Eventually the checksum logic will acquire a complete checksum which can be compared with the checksum that had been previously latched, so as to verify the checksum.
摘要:
A network router has a distributed processing scheme for multicast packets. The router has a look-up and forwarding engine operative in response to the reception of an internet protocol multicast packet to direct the packet to a multiplicity of transmit ports which may or may not be connected to the source network segment from which the multicast packet was received by the router. Each transmit port is associated with a predetermined default network segment and the engine directs the packet to the ports (e.g. across the router's backplane) with an identification of the source network segment and control flags which enable processing means associated with the ports to determine by comparison of the respective network segment and the source network segment whether the packet is bridged from the respective port or routed, with relevant modification of the packet, from that port. The control flags comprises a first flag which can be set to allow the relevant modification and a second flag which can be set to allow the comparison between the source segment and the predetermined default segment.