3com Technologies

Microsemi Frequency and Time Corporation

Mingoa Limited

Broadcom Corporation

Con David Cremin

Anne G O'Connell

Eugene O'Neill

Niall Hanrahan

Mark A Hughes

Una Quinlan

Richard A Gahan

Sorcha O'Callaghan

Neil O Fanning

Raymond Beechinor

Yves Cognet

David Nolan

Micheal Lardner

J Noel Butler

Sorcha Callaghan

Maurice Gleeson

Niall Finbarr Donovan

Jennifer Hamilton

Anne Geraldine O'connell

Various electronic devices may benefit from appropriate power conservation techniques and tools. For example, low power techniques may benefit small form-factor pluggable applications. An apparatus can include a packet parsing functionality that includes a first order shallow packet parser configured to operate at line rate and a second order deep packet parser configured to operate only on received filtered packets and received packets destined for a management and/or central processing port. The apparatus can also include a microprocessor configured to manage the apparatus and configured to operate at a low duty cycle. The apparatus can further include a packet generator configured to be active only when generating certain packets of interest. The packet parsing function, the microprocessor, and the packet generator can be configured to provide data from a host port of a small form-factor pluggable device toward an optical port of the small form-factor pluggable device.

Low power techniques for small form-factor pluggable applications

A method of providing forward error correction on an Ethernet point-to-point link, constituted of: receiving at one end of the point-to-point link an input data stream, wherein the input data stream is a 10 bit symbol encoded serial data stream at a first data rate; decoding the 10 bit encoded data stream to a 9 bit symbol data stream; increasing the data rate of the 9 bit symbol data stream to a second data rate; for each segment of a predetermined number of 9 bit symbols generating a respective plurality of parity symbols; combining the segments and the generated respective plurality of parity symbols into FEC appended segments; encoding the FEC appended segments into an output 10 bit symbol encoded data stream; and transmitting the output 10 bit encoded stream on the point-to-point link at the second data rate.

Ethernet point to point link incorporating forward error correction

A method of commencement of operation of a communication system such as an Ethernet OAM system enables an endpoint (A) to transmit and receive repetitive connectivity check messages on a link between the endpoint and a remote endpoint (B). A loss of connectivity with the remote endpoint is determined by the absence of received connectivity check messages within a monitoring interval. The commencement of the monitoring interval is delayed until a predetermined number of valid connectivity check messages has been received. The method may be implemented by use of a counter for received connectivity check messages and an additional waiting state in a state machine.

Detection of link connectivity in communication systems

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.

Enhancing accuracy of service level agreements in ethernet networks

Multicast packets that are received on a port of a network device and forwarded to multiple output ports are stored in memory and respective primary control entries which define them are converted to secondary control entries defining multiple unicast packets before a scheduling algorithm is applied. The packets are reconstituted after the application of the scheduling algorithm has been applied to the control entries. For VPLS packets that are received on a single port and replicated multiple times on one or more output ports, a replication database may be used in conjunction with a replication engine to convert the control entry for a received packet into multiple control entries defining unicast packets for each of the destination ports before the scheduling algorithm is applied. This method is applicable to the replication of packets onto a Virtual Private LAN.

Maintenance of bandwidth allocation for traffic including multicasts

A method for distributing addressed data packets from an input channel to a multiplicity of packet queues includes receiving said addressed data packets and, responsive to first hashed addresses, distributing the addressed data packets to said queues in accordance with said first hashed addresses. A first hash function is applied to selected address data of each of said addressed data packets to produce said first hashed addresses. At the same time a succession of different hash functions is applied to said selected address data in each of the packets to produce second hashed addresses and occurrences of each of the second hashed addresses are counted so as to obtain for each of said different hash functions a respective one of a plurality of set of counts, each such set representing the distribution of said packets that would occur in said queues if the respective one of the different hash functions had been applied to said addressed data packets. The sets of counts are analyzed to determined which one of them represents a best distribution of said packets and the hash function associated with the best distribution is applied to incoming packets in place of the said first hash function.

System and method for dynamically mapping a high speed link to a multiplicity of low speed trunked links

A plurality of serial data streams are transmitted on a corresponding plurality of lines at a common frequency in equal groups of symbols. A framing signal composed of groups of symbols corresponding in number to groups of data symbols is transmitted on an additional control line. Each group of symbols in the framing signal includes a majority of symbols capable of representing a first plurality of code words and a second plurality, substantially less than the first plurality, of valid code words, and a minority of symbols which constitute parity check symbols. Each of the valid code words consists of a first sub-group of similar symbols and a second plurality of similar symbols. For some of the valid code words the symbols in the first sub-group are similar to the symbols in the second sub-group. For other valid code words the symbols in the first sub-group are different from the symbols in the second sub-group. The valid code words correspond to groups which represent (a) start of a data packet or block; (b) data/(c) a gap between groups of data; and (d) an idle state. The sequence of groups in the framing signal is monitored by means of a state machine.

Framing codes for high-speed parallel data buses

Growing community of inventors

Rochestown, Ireland

Con David Cremin