Advanced Micro Devices Corporation

Broadband Royalty Corporation

Arris Group, Inc.

Nader Vijeh

Ian S Crayford

William Lo

Adisak Mekkittikul

David R Staab

Jeffrey M Blumenthal

John M Wincn

William J Tuohy

An asynchronous metropolitan packet transport ring having per-flow QoS. Asynchronous packetized data flow in one direction through a fiber optic loop. A number of Metropolitan Packet Switches (MPS) are coupled to the fiber optic loop. An MPS allows packetized data from an upstream MPS to flow to a downstream MPS over a segment of the fiber optic loop. The MPS also puts packetized data onto and pulls packetized data off of the fiber optic loop. Thereby, flows can access the fiber optic loop via the MPS's. The MPS's also regulate the data rates on a per-flow basis according to setup information supplied by a Ring Management System (RMS). If one segment of the fiber loop becomes overly congested, the MPS guarantees quality of service for those flows by deallocating available bandwidth from flows upstream to the point of congestion. Utilization of packet transport ring capacity is optimized by allocating any bandwidth that becomes available to active flows according to a pre-specified weighting scheme.

Per-flow rate control for an asynchronous metro packet transport ring

In a metropolitan area network, a method and system for maintaining an accurate total of the amount of allocated bandwidth on the network. A plurality of incoming packets are assigned to a respective plurality of queues of a metropolitan area network switch. Using a fair arbitration scheme, the respective queues are configured to empty at a specified output rate. A finish time for each respective queue is computed, the finish time describing a time at which the respective queue will be emptied using the output rate. The plurality of queues are grouped into multiple groups in accordance with their respective finish times. The earliest group includes the reserved rates of those queues having a finish time indicating an empty condition at a first time increment. The second earliest group includes the reserved rates of those queues having a finish time indicating an empty condition at a second time increment later than the first time increment, and so on. The amount of allocated bandwidth on the network is determined by tracking the sum of the reserved rates of all the multiple groups. The first time increment, second time increment, and the like are indexed with respect to a schedule clock. The earliest group thus indicates those queues that will have an empty condition at a next time increment of the schedule clock. The determination of the amount of allocated bandwidth can be accomplished in real time, thereby allowing the efficient allocation of unallocated bandwidth in real time.

Method and system for bandwidth allocation tracking in a packet data network

An asynchronous metropolitan packet transport ring having guaranteed QoS. Asynchronous packetized data flow in one direction through a fiber optic loop. A number of Metropolitan Packet Switches (MPS) are coupled to the fiber optic loop. An MPS allows packetized data from an upstream MPS to flow to a downstream MPS over a segment of the fiber optic loop. The MPS also puts packetized data onto and pulls packetized data off of the fiber optic loop. Thereby, flows can access the fiber optic loop via the MPS's. The MPS's also regulate the data rates on a per-flow basis according to setup information supplied by a Ring Management System (RMS). If one segment of the fiber loop becomes overly congested, the MPS guarantees quality of service for those flows by deallocating available bandwidth from flows upstream to the point of congestion. Utilization of packet transport ring capacity is optimized by allocating any bandwidth that becomes available to active flows according to a pre-specified weighting scheme.

Guaranteed quality of service in an asynchronous metro packet transport ring

A method and system for implementing weighted fair flow control on a metropolitan area network. Weighted fair flow control is implemented using a plurality of metro packet switches (MPS), each including a respective plurality of virtual queues and a respective plurality of per flow queues. Each MPS accepts data from a respective plurality of local input flows. Each local input flow has a respective quality of service (QoS) associated therewith. The data of the local input flows are queued using the per flow queues, with each input flow having its respective per flow queue. Each virtual queue maintains a track of the flow rate of its respective local input flow. Data is transmitted from the local input flows of each MPS across a communications channel of the network and the bandwidth of the communications channel is allocated in accordance with the QoS of each local input flow. The QoS is used to determine the rate of transmission of the local input flow from the per flow queue to the communications channel. This implements an efficient weighted bandwidth utilization of the communications channel. Among the plurality of MPS, bandwidth of the communications channel is allocated by throttling the rate at which data is transmitted from an upstream MPS with respect to the rate at which data is transmitted from a downstream MPS, thereby implementing a weighted fair bandwidth utilization of the communications channel.

Method and system for weighted fair flow control in an asynchronous metro packet transport ring network

A system is provided for use in a network to provide authentication of packets of data, provide security to ensure the prevention of unauthorized receipt of data, to provide improved monitoring of the packets of data transmitted and received over such a network, and to detect changes in the network topology. Repeaters utilized in the network are provided with the capability to detect and interpret packet data and the source address (SA) and destination address (DA) fields to provide the improved features.

Address tracking over repeater based networks

A discrete integrated repeater device and port MAU/AUI functions shares resources among its several ports. The device includes a single multi-bit free running counter providing preselected timing intervals to a plurality of latches. A signal undergoing measurement clears the latch while a preselected timing signal sets the latch. Receipt of a timing signal at a set latch indicates success or failure of some particular condition under test. The device satisfies an IEEE 802.3 specification for execution of a link integrity test. The device is also able to selectively disable or enable the link integrity test function for particular ports. A plurality of latches, one associated with each port, is set upon carrier sense detection at the particular port. A token passing mechanism implemented with a daisy chained line coupled to each latch enables a polling of each latch to provide carrier sense information about each port in a serial format. The device shares a single PLL among all its ports by producing a logical sum of carrier sense inputs to enable activation of the PLL. A collision indication signal will override operation of the PLL to ensure data integrity and to allow the PLL to reacquire lock on its reference clock.

Integrated multi-port repeater having shared resources

An integrated media attachment unit (MAU) operative for interfacing Digital Terminal Equipment (DTE) on a Local Area Network (LAN) using twisted pair media. The twisted pair function as either a DTE MAU or a repeater MAU. A line driver for the twisted pair differential signal provides a ramped response with low jitter while an improved Attachment Unit Interface (AUI) driver uses CMOS technology and provides simplified End-of-Transmission Delimiter (ETD) control. The twisted pair MAU includes a combined override and status indication of link status and an additional feature to allow automatic polarity reversal of differential signal input lines and polarity status signalling.

AUI to twisted pair loopback

A system is provided on an Integrated Multiport Repeater (IMR) to monitor the activity of the IMR when the repeater is in minimum mode. Through this system the serial output pin outputs status based upon inputs at two input pin the signal in and the clock signal. In a preferred embodiment there are four different status outputs, partition, loopback/link, Bitrate and SQE/Polarity. This system finds use in low end applications where complex control circuitry is not desired.

Enhanced port activity monitor for an integrated multiport repeater

A discrete repeater having a predetermined number of ports includes an expansion port permitting connection of one or more of similar devices to produce a single repeater unit having an increased number of ports. The expansion port includes two bidirectional channels, an output channel and two input channels. An arbiter function connects to each discrete repeater to assert appropriate signals to permit the discrete repeaters making up a repeater unit to exchange data and collision information. This exchange of data is used in a state machine of the discrete repeaters to provide a repeater unit with distributed repeater and relay functions.

Expandable repeater

A counter for attribute stored in an Ethernet system is partitioned such that the storage section is separated from the incrementors section. In so doing, counters are implemented in a significantly less space than if the counters were implemented as individual counters. The counter utilizes random access memory as the storage section and a 32 bit incrementor. As the incrementor section along with a pair of latches to implement the counter.

Counter for attribute storage for use in a repeater

A system is provided for use in a network providing security to ensure the prevention of unauthorized receipt of data. The system utilizes a jamming sequence to prevent unauthorized ports from receiving certain data. Repeaters utilized in the network are provided with the capability to detect a particular data sequence to provide the improved features.

Repeater security system

Method and apparatus for squelch circuit in network communication

An apparatus and method for providing a selectable novel reconnection algorithm for a repeater partition state machine to use in reconnecting a partitioned port. The reconnection algorithm permits selection of one of a first or a second partitioning/reconnection algorithm from a set of partitioning/reconnection algorithms. The first partitioning/reconnection algorithm corresponds to the IEEE 802.3 Standard partitioning/reconnection algorithm. The second partitioning/reconnection algorithm reconnects a partitioned port only upon minimum duration collision-free transmit activity from a partitioned port. The apparatus includes a partition state machine responsive to a counter controlled by a signal indicating the particular partitioning/reconnection algorithm selected and a device for selecting the algorithm. The signal determines whether the counter responds to receive and transmit activity or only to transmit activity. When the counter times that the minimum duration of the appropriate activity has elapsed and the partition state machine has seen activity without a collision, the port is reconnected as appropriate.

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Sunnyvale, CA, United States of America

Nader Vijeh