483 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.

Apparatus for recording and collecting the installed location of cable modems in a cable data network comprises a network manager for maintaining and collecting cable modem location information. Components of the network manager maintains a software agent that manages a database of modem installation and status information. Responsive to a manager request, the component software agent provides the installation and status information to the network manager. The information is displayed as a map which can show the topology of the cable modem's location in the network with respect to other modems and other components of the network.

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 system and method for proxying Dynamic Host Configuration Protocol (“DHCP”) network services for a network device, such as, a customer premise equipment entity, on a network device, such as, a cable modem, include creating a specialized proxy task for the customer premise equipment entity on the cable modem. One method of the present invention includes intercepting DHCP message flow between a customer premise equipment having a specialized proxy task created on the cable modem and a DHCP server selected by the customer premise equipment entity. The methods further include modifying lease time intervals prior to providing a routable network address lease to a customer premise equipment entity and renewing an initial lease for the customer premise equipment entity by a cable modem prior to expiration of the lease time interval provided by a DHCP server. The methods include using known protocols, such as, for example, the Dynamic Host Configuration Protocol.

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 system for providing video-on-demand service, broadband internet access and other broadband services over T-carrier systems including a pull multiplexer cherrypicker at the head end is disclosed. The pull multiplexer receives upstream requests and cull out MPEG or other compressed video packets, IP packets and other data packet types to satisfy the requests or to send pushed programming downstream. The downstream can be DSL or HFC. Each customer has a cable modem, DSL modem or a gateway which interfaces multiple signal sources to a LAN to which settop decoders, digital phones, personal computers, digital FAX machines, video cameras, digital VCRs etc. can be attached. Each gateway can coupled the LAN to a DSL line or HFC through a cable modem or a satellite dish through a satellite transceiver. A PSTN and conventional TV antenna interface is also provided.

The present invention provides IP-centric, multi-channel, time-shifted and real-time telecommunications services to a plurality of system users. The system can capture both digital and analog multi-channel feeds and, through a cross-connect layer, can convert the signals to a digital format and subsequently send them to an encoder to be compressed. The encoding process can use a firmware upgradeable software developed to decrease data bitrates while retaining quality of the information at a desired level. The encoded, compressed signals may either be stored on a data-on-demand server for later viewing services, such as television / video-on-demand or audio-on-demand, or may be streamed directly to system users using a Media Streaming Subsystem (MSS). The MSS can be responsive to a system user request and operative to forward a selected stream of compressed digital data to the system user via a gateway means. The system can include a System Controller that can provide management and control of the system components and services provided by the system. The gateway means is able to receive compressed digital data from the Media Streaming Subsystem and transmit that data to a system user sending a request over a communication network. A cable modem, DSL modem or other appropriate interface can be located at each system user's location, thereby providing a means for sending multiple signal sources to a system user's Local Area Network (LAN) to which the User Computing Device(s) (UCD) of a system user are connected. The UCD receives the compressed data from the gateway means, subsequently decodes this compressed data and presents this decompressed information to the system user via a presentation system which may or may not be integrated into the UCD, thereby providing the requested entertainment services to the system user.

A method and apparatus for time synchronization in a communications system such as a system including cable modems is provided. The synchronization method comprises the steps of receiving a first timestamp from a headend unit with the cable modem, and generating a first cable modem time reference with the cable modem in response to the receipt of the first timestamp. The cable modem then receives a second timestamp from the headend unit and generates a second cable modem time reference in response to the receipt of the second timestamp. A headend difference time comprising the difference of the first and second timestamps is then generated as is a cable modem difference time comprising the difference of the first and second cable modem time references. A clock error time that comprises the difference of the headend difference time and the cable modem difference time is then generated as well as a correction factor in response to the clock error time. The local clock of the cable modem is then synchronized with the master clock of the headend unit through the adjusting of the output of the local clock output in response to the correction factor. The correction factor in one instance comprises an offset value representative of the amount of clock error per local clock pulse. This offset value is added to an accumulator on each local clock pulse, and the local clock output is adjusted when the accumulator rolls over. The synchronized clock signal can then be utilized to determine a time slot in which the cable modem can transmit an upstream signal to the headend without colliding the upstream signal with upstream signals from other modems in the system.

A cable modem uses a CATV network as an information transfer medium. To a cable modem proper that is connected by way of a coaxial cable to a CATV network, an expansion unit is attached that has a wireless LAN function that permits wireless communication with an information processing terminal. The expansion unit is removably attached to the cable modem proper by use of a plug and connector.

A system for providing video-on-demand service, broadband internet access and other broadband services over T-carrier systems including a pull multiplexer cherrypicker at the head end is disclosed. The pull multiplexer receives upstream requests and cull out MPEG or other compressed video packets, IP packets and other data packet types to satisfy the requests or to send pushed programming downstream. The downstream can be DSL or HFC. Each customer has a cable modem, DSL modem or a gateway which interfaces multiple signal sources to a LAN to which settop decoders, digital phones, personal computers, digital FAX machines, video cameras, digital VCRs etc. can be attached. Each gateway can coupled the LAN to a DSL line or HFC through a cable modem or a satellite dish through a satellite transceiver. A PSTN and conventional TV antenna interface is also provided.

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.

This invention permits the upstream transmission of short packets of information in a cable TV system, and blocking upstream noise at all other times, and does so without interfering with image quality of normal TV viewing. A remotely operable ingress noise blocking filter is placed at the terminating junction between a subscriber's coaxial drop cable and a corresponding feeder tap in a cable TV system. The ingress noise blocking filter contains a high pass filter to pass the normal TV band. This high pass filter is bypassed by a section containing low pass filters and a switch operated when receiving a control signal from a cable modem during those short durations the cable modem is authorized to transmit an upstream signal. Low pass filters isolate the switching elements so that switching transients cannot occur in the downstream TV band. The level of the amplitude of the downstream signal is unaffected whether the switching elements are open or closed. Further, the switching arrangement provides a relatively constant impedance, both when the switching element is on and off to provide a high return loss and avoid signal reflections and maintain signal quality. In a diagnostic mode, the location of each noise source is determined by correlating the energy measured at each a set of frequencies across the band at the headend during those periods when the cable modem is allowed to transmit versus the energy received during those periods when the same cable modem is not authorized to transmit.

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 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 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 method and apparatus for providing quality of service parameters for transmissions of multicast streams on a cable network is provided. A cable network headend connects an external network to a hybrid fiber coax or cable network. The cable network headend maintains a table of cable modems with entries associating each cable modem with one or more quality of service parameters. Virtual cable modem entries are created for multicast streams when indications of quality of service for multicast streams are received by the cable network headend. Multicast packets arriving at the cable network headend are processed using the stored quality of service parameters for the corresponding multicast stream. The multicast packets may then be transmitted, queued, or dropped depending on the specified parameters and traffic shaping or policing algorithms.

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.