478 results about "Cable modem" patented technology

A computing environment with methods for monitoring access to an open network such as the Internet, is described. The system includes one or more client computers, each operating applications (e.g., Netscape Navigator or Microsoft Internet Explorer) requiring access to an open network, such as a WAN or the Internet, and a router or other equipment that serves a routing function (e.g., a cable modem) for the client computers. A centralized security enforcement module on the router maintains access rules for the client computers and verifies the existence and proper operation of a client-based security module on each client computer. The router-side security module periodically sends out a router challenge via Internet broadcast to the local computers on the network. If the client-side security module is installed and properly operating, the client-side security module responds to the router challenge. The responses received by the router-side security module are maintained in a table. Each time the router receives a request from a client computer to connect to the Internet, the router-side security module reviews the table and analyzes whether or not the computer requesting a connection to the Internet properly responded to the most recent router challenge. If it determines that the computer has properly responded to the router challenge, then it permits the computer to connect to the Internet. If a computer has not properly responded or if a computer has not answered the router challenge, then the computer is not allowed to connect to the Internet as requested.

A networked computer system has a plurality of servers and a plurality of distributed clients, which may be devices or computers. Each client has a boot operating system (OS). Upon startup, the boot OS in each client automatically initiates a connection to one of the servers via the Internet. The boot OS can detect the type of medium (e.g., cable modem, DSL) to which the client is connected. The server automatically downloads a base OS and dynamically configures a suite of applications on the client without running the standard installation programs. One included application is an Internet telephony application, allowing a user to plug a standard telephone into the client appliance or computer, pick up the telephone, and automatically dial out using long distance Internet telephony. Optionally, the server may download a plurality of operating systems that are automatically initiated to run concurrently on the client. The clients use a random access memory (RAM) caching technique. A first portion of each OS or application is downloaded at startup and maintained in the client RAM, containing the files needed to launch the OS or application. If the client processes a request for an OS or application program file not in the client's RAM, the requested file is automatically downloaded from the server.

A Power Line Communications (PLC) device includes a processing module, memory, and a communication interface. In a first operation, the PLC device determines that the PLC device will service communications with a first remote PLC device according to a first PLC communication standard and configures the communication interface to service communications according to the first PLC communication standard. In a second operation, the PLC device determines that the PLC device will service communications with a second remote PLC device according to a second PLC communication standard and configures the communication interface to service communications according to the second PLC communication standard, wherein the first PLC communication standard and the second PLC communication standard are differing and incompatible PLC communication standards. The PLC device may also configure the communication interface to service non-PLC communications such as LAN, WAN, WLAN, cable modem, and other communications.

A method and system for optimizing performance in a data-over-cable system. The method includes determining parameters for data transmission on an upstream channel of the data-over-cable system, and negotiating use of the parameters. A measurement is made of a signal-to-noise ratio (“SNR”) on the upstream channel. Associated with the SNR and a target packet-error-ratio (“PER”) are parameters that provide optimal data throughput. The parameters, such as symbol rate, type of modulation, or amount of error correction, are used to construct a message that is sent to the cable modems. The message instructs the cable modems to reconfigure themselves to transmit according to the parameters. The reconfiguration helps ensure optimal performance.

A system and methods are shown for traffic shaping and congestion avoidance in a computer network such as a data-over-cable network. A headend of the data-over-cable system includes a traffic shaper configured to calculate a packet arrival rate from a cable modem and a traffic conditioner configured to calculate an average queue size on an output interface to an external network. For example, the traffic shaper compares the packet arrival rate to three packet arrival thresholds including a committed rate threshold, a control rate threshold and a peak rate threshold. If the calculated packet arrival rate falls between the committed threshold and control rate threshold, the traffic shaper applies a link layer mechanism, such as a MAP bandwidth allocation mechanism, to lower the transmission rate from the cable modem.

A protection CMTS is available to immediately service a cable modem should that modem's service from a working CMTS fail for any reason. To speed the service transfer (cutover) from the working CMTS to the protection CMTS, the cable modem may preregister with the protection CMTS well before the cutover becomes necessary. The cable modem's registration with both the working CMTS and the protection CMTS preferably employs a single IP address, so that the cable modem need not obtain a new IP address during cutover. While the cable modem may register with both the working CMTS and the protection CMTS, the devices are designed or configured so that only the working CMTS injects a host route for the cable modem into the appropriate routing protocol. Only after cutover to the protection CMTS does the protection CMTS inject its host route.

A method and apparatus for initialization and operation of cable modems comprising initializing the cable modems over management channels and transferring the cable modems to a data channel for operation. Initialization over a management channel overcomes certain prior art constraints associated with initialization over the data channel.

The present invention provides a facility management platform to monitor and view the status of a plurality of individually addressable downstream devices including, but not limited to, addressable terminals, IRG's, settops, cable modems, taps, nodes, and/or hubs at a network control center. The FMP may display problems at these downstream devices, for example, power loss, and/or may automatically notify the appropriate companies and/or personnel to correct the problem.

A communication system that includes a supervisory node (e.g., a headend) and one or more remote nodes (e.g., cable modems). Packets are transmitted between the supervisory node and the one or more remote nodes via RF channels. A plurality of the RF channels are bonded, such that packets may be transmitted via any one or more of the RF channels that are bonded. Bonding may include higher-layer bonding and/or lower-layer bonding. In higher-layer bonding, the communication system further includes a forwarder and a plurality of edge modulators. Each edge modulator is connected to a different RF channel or group of RF channels. The forwarder determines to which edge modulator one or more packets or flows are to be transmitted. In lower-layer bonding, a packet is split into pieces. The pieces are assigned to respective RF channels that are associated with an edge modulator for transmission to a remote node.

A method and apparatus for providing message authentication between a first device (such as a provisioning server) and a plurality of other devices (such as cable modems) without need to share a secret key between the first device and the plurality of second devices.

A system and method permits a network management agent executing on a customer premise equipment (CPE) component to determine whether a router is coupled between the CPE component and the cable modem through which the CPE component communicates with a data-over-cable network. The network management agent executing on the CPE component encapsulates the MAC address of the CPE component in a network management message that is sent to a server at the head end of the data-over-cable network. The head end compares the encapsulated MAC address with the MAC address of the device coupled to the cable modem that sent the network management message. If the MAC addresses are not the same, the server at the head end sets a router status element in the network management message response and sends it to the agent executing on the CPE component. The agent may then interrogate the router status element and determine whether a router is coupled between the CPE component on which it is executing and the cable modem through which it is coupled to the data-over-cable network.

The present invention enables the self-diagnosis functionality by embedding a cable modem with the CMTS system with mechanisms to redirect the signals from external connections to the embedded cable modem, thereby enabling the end user to fully test the CMTS using a suite of diagnostic tests. The embedded cable modem integrates the external CM, computer and diagnostic software in the chassis, or alternatively onto the CMTS card in the chassis. The invention enables the end user to fully test the functionality as a stand-alone unit, without relying on any external test equipment or methods. It also enables the end user to diagnose the CMTS from a remote location. Another major advantage of the present invention is that it enables the CMTS/CM function to be verified over the entire physical layer parameter set (frequency, symbol rate, FEC, signal levels, etc.) while not interrupting any of the services that are on the ‘live’ HFC plant.

A head-end in a data-over-cable system transmits a multicast message in a downstream channel to all the cable modems in a particular MAC layer. The message includes an address field that contains an upstream channel multicast MAC address that identifies a particular channel, and is used to send a multicast message for which only cable modems transmitting in the upstream direction in that channel are to respond. When the message is received by the cable modems, the cable modems compare the upstream channel multicast MAC address with addresses stored in a memory. If a match is found, indicating that the cable modem happens to transmit in the upstream direction in the particular channel, it processes the message. If no match is found, the message is discarded. The upstream channel multicast MAC address helps noise avoidance or redundancy problems associated with a particular channel to be quickly remedied, and avoids the head-end from having to send out a large number of unicast messages in order to communicate with all the modems sharing a given upstream channel.

A system and method are disclosed for transmitting upstream data from a cable modem within a cable television plant. One aspect of the invention pertains to a method that includes transmitting a first portion of the upstream data on a first upstream channel from the cable modem and transmitting a second portion of the upstream data on a second upstream channel from the cable modem. The second upstream channel differs from the first upstream channel. In another aspect, the invention pertains to a cable modem that includes a processor configured to initiate transmission on multiple upstream channels. The cable modem further includes an upstream transmitting component operating in conjunction with the processor and configurable by the processor to transmit data over multiple upstream channels. In one embodiment, the upstream transmitting component includes a first transmitter that is capable of being configured by the processor to transmit data at both a first upstream channel and a second transmitter that is capable of being configured by the processor to transmit at a second upstream channel that differs from the first upstream channel.