Abstract: A method of determining frame loss between two management points (C, D) in an Ethernet network, in which the management points each transmit frames to each other and each of the two management points transmits to the other, in regular intervals, measurement messages which contain current counts of frames transmitted and received by the respective transmitting management point. At least one of the two management points responds to a received management message to compute from counts of actual packets transmitted and/or received by a given one of the management points the frame loss at the given management point. At least one of the management points computes the frame loss only once in a measurement interval which consists of a multiplicity of the regular intervals and employs in the computation the counts indicated by the measurement message most recently received by the one of the management points.

Abstract: A method of determining frame loss between two management points (C, D) in an Ethernet network, in which the said management points each transmit frames to each other and each of the said two management points transmits in regular intervals to the other measurement messages which contain current counts of frames transmitted and received by the respective transmitting management point. At least one of the said two management points responds to a received management message to compute from counts of actual packets transmitted and/or received by a given one of the management points the frame loss at said given management point. At least one of the management points computes the said frame loss only once in a measurement interval which consists of a multiplicity of said regular intervals and employs in the computation the counts indicated by the measurement message most recently received by said one of the management points.

Abstract: Ethernet ‘operation, administration and management’ (OAM) circuits contain monitoring points that exchange ‘management” messages, particularly connectivity fault management messages and performance monitoring messages. This invention is a search process to identify a receiving monitoring point and also a further process to verify, particularly for continuity check messages, a management endpoint. The search processes use information carried in a message, in a hardware efficient method with predictable search times independent of search table size.

Abstract: A method is described that converts a first flow of data words into a second flow of data words. The first flow of data words has a first data rate and the second flow of data words has a second data rate. The second data rate is greater than the first data rate such that the second flow of data words under-runs. The method also includes transmitting the second flow of data words over a plurality of communication links. A data alignment data structure is transmitted over each of the communication links for each under-run.

Abstract: A bus interface coupling an asynchronous bus and a slave device, such as a memory. The bus interface comprises an asynchronous bus controller and a synchronous bus controller. The asynchronous bus controller is implemented as two PAL state machines. One state machine controls the connection and disconnection phases of the bus protocol, while the other controls the data transfer phase. The synchronous bus controller controls data transfer between the bus and the slave device. The state machines are closely interlinked to each other and the synchronous bus controller allowing for increased bus efficiency.