Abstract: A method and system for digital communication wherein nodes exchange messages at a first data rate in order to coordinate testing at a second, higher data rate. After testing is completed, the nodes exchange test results at the first data rate, and if conditions are satisfactory for operation at the second data rate user data are transmitted at the second data rate. Otherwise, user data are transmitted at the first data rate.

Abstract: A method and system for digital communication wherein nodes exchange messages at a first data rate in order to coordinate testing at a second, higher data rate. After testing is completed, the nodes exchange test results at the first data rate, and if conditions are satisfactory for operation at the second data rate user data are transmitted at the second data rate. Otherwise, user data are transmitted at the first data rate.

Abstract: A method for link-level flow control includes establishing a plurality of logical links over a physical link between a transmitting entity and a receiving entity in a network. Respective maximum limits of transmission credits are assigned to the logical links, the credits corresponding to space available to the links in a dynamically allocable portion of a receive buffer at the receiving entity, such that a sum of the maximum limits for all of the logical links corresponds to an amount of space substantially larger than a total volume of the space in the dynamically allocable portion of the receive buffer.

Abstract: A method and switch system for optimizing the use of a given bandwidth in different communication network connections. The method comprises providing port bandwidth resources at a port of the network, and dynamically and automatically allocating said port bandwidth resources. In a preferred embodiment, the bandwidth resources include a cluster of 3 ports with a given bandwidth of 12x, which can be declared as a 12x port and two 4x ports or as a trio of three 4x ports. The declaration causes dynamic and automatic configuration of the three ports, thereby optimizing the use of the given bandwidth.

Abstract: Apparatus for interfacing a computing device with a network includes a switch and an interface adapter. The interface adapter includes packet generation circuitry, for preparing a packet for transmission onto the network through the switch, and a buffer, coupled to receive and store the packet prepared by the packet generation circuitry. An output interface, coupled between the buffer and a first port of the switch, submits a notification to the first port that the packet has been prepared in the buffer. Upon receiving a response from the first port indicating that a second port of the switch, connected to the network, is ready to transmit the packet, the output interface conveys the packet to the first port, whereupon the first port passes the packet to the second port for transmission onto the network.

Abstract: A method for sampling a data stream (22) includes receiving a segment of the data stream containing a sequence of known data, together with a source-synchronous clock signal (20), and generating a series of trial sampling clocks (60) by applying a corresponding series of different trial delays to the received clock signal The received segment of the data stream is sampled using each of the trial sampling clocks in turn to generate sampled data. The known data are compared to the sampled data to find comparison results for each of the trial sampling clocks. Responsive to the comparison results, a final delay is set, to be applied to the received clock signal so as to generate a final sampling clock for use in sampling the data stream subsequent to the segment.

Abstract: A device for switching packets in a network includes a switching core and a plurality of ports, coupled to pass the packets from one to another through the switching core. The ports include, with respect to each packet among the packets switched by the device, a receiving port, coupled to receive the packet from a packet source, and a destination port, to which the packet is passed for conveyance to a packet destination. The ports also include one or more cache memories, respectively associated with one or more of the ports, each of the cache memories being configured to hold a forwarding database cache for reference by the receiving port with which the cache memory is associated in determining the destination port of the packet.

Abstract: A method for link-level flow control includes establishing a plurality of logical links over a physical link between a transmitting entity and a receiving entity in a network. Respective maximum limits of transmission credits are assigned to the logical links, the credits corresponding to space available to the links in a dynamically allocable portion of a receive buffer at the receiving entity, such that a sum of the maximum limits for all of the logical links corresponds to an amount of space substantially larger than a total volume of the space in the dynamically allocable portion of the receive buffer.