Abstract: A remote PHY comprises circuitry operable to communicate with a converged cable access platform and a plurality of cable modems in accordance with Data Over Cable Service Interface Specification (DOCSIS®). The remote PHY comprises buffer circuitry operable to buffer signals to be transmitted to one or more of the plurality of cable modems. The remote PHY may comprise subcarrier insertion circuitry operable to manipulate the contents of the buffer circuitry such that the remote PHY is scheduled to transmit, during a determined time interval, subcarriers having determined characteristics. The subcarriers having determined characteristics may be zero-bit-loaded subcarriers.

Abstract: A user device connected to a CMTS over a network is configured such that upon power-up it can use a universal broadcast SID or a predetermined multicast SID to obtain an initial maintenance during a maintenance window. The predetermined multicast SID is assigned to the device at manufacture based on the type, or class, of device. The CMTS to which the devices connect is configured to schedule exclusive initial maintenance opportunity windows for each type of device in addition to an all-inclusive, or open, initial maintenance opportunity window, during which all types of devices may attempt to register. The order and number of initial maintenance windows within a periodically recurring sequence of windows can be configured by an operator based on the types of devices connected to the network.

Abstract: A token bucket instantiation regulate packets in a traffic flow stream based on a predetermined peak traffic flow rate. The token bucket size is nominally set to zero. An evaluation is made at a device that has received a given packet. The packet is considered conforming and is passed from the device if the token depth of the bucket is zero or greater. The token depth is decreased by the number of byes in the packet that was passed. The token depth is continuously replenished at a predetermined token rate until the predetermined bucket size is attained (the bucket is full). A received packet is deemed nonconforming if the token depth is less than zero; the non-conforming packet is not passed but is processed according to non-conforming criteria. Token bucket instantiations may be implemented in hardware, software or firmware for each traffic flow to regulate traffic to a given user.

Abstract: A user device connected to a CMTS over a network is configured such that upon power-up it can use a universal broadcast SID or a predetermined multicast SID to obtain an initial maintenance during a maintenance window. The predetermined multicast SID is assigned to the device at manufacture based on the type, or class, of device. The CMTS to which the devices connect is configured to schedule exclusive initial maintenance opportunity windows for each type of device in addition to an all-inclusive, or open, initial maintenance opportunity window, during which all types of devices may attempt to register. The order and number of initial maintenance windows within a periodically recurring sequence of windows can be configured by an operator based on the types of devices connected to the network.

Abstract: An active multiplexer contains a switching mechanism that connects one of a plurality of upstream links from corresponding nodes in a communication network to an upstream output based on information contained in a MAP. The MAP contains scheduling information of the next user stations, which are coupled to the nodes, and which are scheduled to transmit in the upstream direction during a period following the current time. Station identifiers are associated with their corresponding node identifier during a ranging burst interval into a station/node table, which is used in conjunction with the MAP to control the active multiplexer. Based on the MAP, the active multiplexer connects the node, as determined from the station/node table, that serves the station that is scheduled to transmit upstream traffic and disconnects other nodes.

Abstract: The receipt at a network access device of an acknowledgement packet from a destination host is anticipated upon the receipt at the network access device of a data packet destined to the host from a centralized scheduler. The access device generates a bandwidth request for sending the acknowledgement packet and sends the bandwidth request to the scheduler before the anticipated acknowledgement packet is received from the host. If aggregation is enabled, the bandwidth request may request enough bandwidth to forward a predetermined number of acknowledgement packets from the host to the scheduler. Aggregation and anticipation may be combined.

Abstract: A user device connected to a CMTS over a network is configured such that upon power-up it can use a universal broadcast SID or a predetermined multicast SID to obtain an initial maintenance during a maintenance window. The predetermined multicast SID is assigned to the device at manufacture based on the type, or class, of device. The CMTS to which the devices connect is configured to schedule exclusive initial maintenance opportunity windows for each type of device in addition to an all-inclusive, or open, initial maintenance opportunity window, during which all types of devices may attempt to register. The order and number of initial maintenance windows within a periodically recurring sequence of windows can be configured by an operator based on the types of devices connected to the network.

Abstract: Leaky bucket state machines police packets and throttle packets of a stream or streams that are flowing from hosts towards the processor of a switch or router of a network. The throttling is performed by measuring and analyzing the actual flow rate(s) of the streams' packets. The actual flow rate(s) is compared to a predetermined threshold, which may be based on historical or estimated normal traffic patterns. If the actual flow rate exceeds the threshold associated with characteristics that relate packets to certain streams, packets are discarded from the streams having excessive flow rates. By discarding excessive packets having characteristics that correspond to packet information that typically causes a switch/router's processor to execute operations, the effects of a DoS attack are minimized while also minimizing the discarding of legitimate traffic packets.

Abstract: A long-term usage profile and a congestion state metric are used to determine QoS treatment to apply to packets corresponding to a given network user. A user's historical long-term use, measured over one or more periods of time, is used to generate a profile that is compared to one or more predetermined usage threshold level(s). If the usage profile, either singular or composite corresponding to whether one or more than one measurement is used respectively, exceeds the threshold(s), QoS treatment is applied to service flow bytes according to the comparison results during times of network channel congestion. Congestion metrics are determined based on a count of the number of bytes dropped during a congestion measurement window. Either the count itself or the count rate of change combined with the count are compared to a congestion threshold. If the measured/derived values exceed a congestion threshold, the channel is deemed congested.