Cisco Technology, Inc.

Mark E Millet

Guenter E Roeck

Charles J Naegeli

Wei-Sing Chen

Sunil Khaunte

Chrisanto Leano

Joseph O'Donnell

Chi-Shing Ng

Anton Okmyanskiy

Feisal Y Daruwalla

Hemant Singh

Harshavardhan Parandekar

Alejandro Schwartzman

James R Forster

De Fu Li

Joanna Qun Zang

Hung-San Chen

Raman Shankara Krishnan

James Clark

Chrisanto De Jesus Leano

John K Chen

Nan Tu

Son D Nguyen

Charles J Naegel

Tin Phan

Joseph C H Fung

Anish Thomas

Yuzon Hao

A wideband cable network system includes multiple wideband cable modems and a Wideband Cable Modem Termination System (WCMTS). The WCMTS operates a Media Access Control (MAC) layer that communicates with the cable modems over multiple different downstream Radio Frequency (RF) channels and upstream RF channels. A wideband failure analytic manager tracks fault indicators associated with the MAC layer communications. Separate failure analytics are then generated, indexed, and correlated for different cable modems and different upstream or downstream channels.

Wideband fault correlation system

Techniques are provided to detect cloning of network device identity when network device is seeking registration for service in a network. A control server manages access to the network in which a plurality of network devices are configured to communicate and serve client devices. The network devices require registration with the service gateway in order to provide services. When network devices register with the service gateway, the service gateway performs local clone detection by looking for active registrations from devices with the same identity and by further communicating with the control server. The control server receives registration request messages associated with network devices seeking registration for service from gateway devices, wherein each registration request message includes data comprising an identifier of the network device that is seeking registration that is derived from data stored within a memory of the network device, and an identifier of the gateway device from which the registration request message is received. The control server evaluates the data contained in registration request messages with respect to stored data in order to determine whether a network device identity has been cloned when its registration request message contains an identifier that is already being used by at least one other network device.

Detecting cloning of network devices

In one embodiment a technique is disclosed for facilitating communication between nodes and a head end of an access network including a head end, at least one shared access upstream channel and at least one downstream channel. A first insertion rate estimate is determined. In at least one embodiment, the first insertion rate estimate may relate to an estimated number of nodes attempting to sign-on to the access network during one or more time interval(s). In at least one embodiment, a frequency of occurrence of initial maintenance opportunities available to a first plurality of network nodes may be dynamically adjusted, for example, using data relating to the first insertion rate estimate. According to one embodiment where the access network corresponds to a cable network, the head end of the cable network may be operable to sign on at least 40,000 cable modems within a time interval of not more than 300 seconds.

Node registration technique implemented in access networks

Methods and apparatus are provided for enhancing security and features during cable modem configuration. According to various embodiments, a cable network head end is configured to ensure that a cable modem subscriber registers with its assigned configuration profile. Techniques for verifying parameters in a received configuration profile, enhancing authentication, preventing access to provisioning servers, securing communications, and enhancing feature sets are provided.

Methods and apparatus for secure cable modem provisioning

A method and a system for providing a service in a network, is provided. In one embodiment, a first modem with a first address, which is identical to a second address of a second modem, requests for services in the network. A modem termination system (MTS) checks whether the first modem is a clone of the second modem. If the first modem is identified to be the clone of the second modem, then, the first modem is restricted from obtaining the requested service. However, the second modem is continuously provided services.

Method and system for cloned cable modem detection

Methods, systems, and computer program products are disclosed for allowing rapid re-provisioning of a cable modem at the MAC/physical layer in a cable modem network. After a cable modem goes through power-up/self-test, i.e., a hard boot, and goes through initial provisioning, the modem is in a steady state in which standard DOCSIS periodic ranging is performed. It is during periodic ranging that the provisioning status, such as bit rate, ISP, etc., can be rapidly changed to allow for 'on the fly' changes in provisioning. A cable modem is synchronized with the cable modem network. The modem is then provisioned once it receives a configuration file from a provisioning system. Periodic ranging is then performed between the modem and the CMTS, located either in a headend or a fiber node in the cable plant. The periodic ranging is interrupted by a command or action taken by the CMTS on the cable modem instead of the modem being affected directly by the provisioning system. Once periodic ranging is broken, either by cessation of polling messages or a ranging abort command, the modem goes directly to re-synchronizing with the cable network and re-provisions, i.e., avoids performing a power-on/self test or hard boot.

Rapid cable modem re-provisioning in a cable network

A system for testing a cable network during normal operation interleaves test signals with live data traffic. Installed cable modems are used to generate the test signals. During live communication, such modems send upstream data at allotted time periods. Periodically, there are time slots when no modem is transmitting on the network. During these times, specific modems may be directed to transmit specific test signals. A controller such as a cable modem termination system directs specific modems to transmit signals at defined frequencies and powers during specific time slots. In this manner, the system can monitor the frequency response of the cable network at various locations, and thereby determine 'on-the-fly' when maintenance or modification is required.

Cable plant certification procedure using cable modems

Methods, apparatus, and computer-readable media are disclosed for performing diagnostic tests of a communication link between a headend and a cable modem without having to assign an IP address to the cable modem. The diagnostic tests are performed at the MAC layer and test the state of the hardware between and including the cable modem termination system (CMTS) and a selected cable modem. By doing so, a network operator is able to more easily focus in on a potential problem in cable RF/MAC connectivity between the two components by first eliminating (or identifying) a problem with hardware before focusing on problem-solving at the software level, typically at the Network layer, at which point the cable modem is assigned an IP address.

Media access layer ping protocol for diagnosing cable modem links

A CMTS redundancy technique requires at least two CMTS interfaces (e.g., line cards) on one or more CMTS chassis at the head end of a cable network. One of the CMTSs serves as a backup or 'protecting' CMTS. When another CMTS (a 'working' CMTS) becomes unavailable to service its group of cable modems, the protecting CMTS takes over service to those cable modems. The SWITCHOVER takes place transparently (or nearly transparently) to the cable modems. The protecting CMTS provides service on the same downstream channel as used by the working CMTS. The cable modems need not modify any settings pursuant to their cable modem communication protocol (e.g., DOCSIS ranging). This transparency to the cable modems is realized by keeping the working and protecting CMTSs in synchronization regarding service parameters for the cable modems. In other words, the protecting CMTS maintains a list of current parameters for allowing service to the cable modems.

Cable network redundancy architecture

Disclosed is an apparatus and method for simulating a plurality of cable modems for testing a device, such as a head end complex. In general terms, the present invention provides a multiple cable modem simulator and techniques for setting up and executing the same. In one implementation, the multiple cable modems are simulated by simulating multiple MAC (media access control) state machines for multiple cable modems. In other embodiments, a simulator of the present invention includes a mechanism for simulating physical operating conditions of the simulated cable modems. For example, even when the simulator is located at a single test location, different distances and power levels may be simulated for the different simulated cable modems.

Method and apparatus for simulating a plurality of cable modems

Methods, apparatus, and computer-readable media are disclosed for creating a virtual lookahead upstream receiver in a single physical upstream receiver in a CMTS, thereby avoiding having to dedicate an upstream receiver strictly for lookahead capability. A lookahead receiver is used to determine whether a potential alternative frequency is better than the frequency presently being used. A physical upstream receiver is assigned to operate under a set of operational parameters associated with a logical lookahead receiver during a particular time slot. The logical receiver receives upstream data from a selected test modem using an alternative upstream frequency. It is then determined whether the alternative upstream frequency is preferable over the frequency presently being used. If so, the physical receiver is configured to operate normally under the set of operational parameters associated with the logical receiver. At this stage, all modems in a particular group, including the selected modem, hop over to the alternative frequency. The physical receiver can be divided into any number of logical receivers.

Method and apparatus for creating virtual upstream channels for enhanced lookahead channel parameter testing

A method and system for locating faulty components in a cable modem network configured within a hybrid fiber-coaxial cable television system by tabulating modem performance data are described. A method of isolating problematic components in a cable modem network includes determining whether a cable modem transmitted a polling message to a central destination during the modem's allotted time interval. A media access control layer, located within a cable modem termination system (CMTS), keeps a miss count for the cable modem that reflects the number of times the cable modem does not transmit a polling message to the CMTS during its allotted time. The media access control layer determines whether the cable modem is changing states. This data and the miss count are tabulated in a form that can be analyzed by a correlation module to determine characteristics of the cable television plant.

Method and apparatus for locating a faulty component in a cable television system having cable modems

A media access control (MAC) unit in a CMTS assigns a normal time slot to a cable modem being tested for its upstream transmission quality. An FFT generator or engine operating in conjunction with the CMTS is informed of this normal time slot. A dummy time slot, not assigned to any cable modem, is created and the FFT generator is informed of the dummy time slot. A number of FFT measurements of the upstream channel are generated during the normal time slot and during the dummy time slot. FFT measurements of the upstream spectrum taken during the normal time slot are compared to FFT measurements taken during the dummy time slot. Through this comparison, undesirable noise spurs, if any, can be detected in the upstream spectrum caused by the cable modem being tested.

Method and apparatus for measuring quality of upstream signal transmission of a cable modem

A technique is disclosed for selectively adjusting the power and/or frequency of cable modems without relying solely on the most recent measurement of these values to determine whether a change is necessary. Rather, it considers multiple recent measurements and from these makes its assessment. In one approach, the technique employs an average of the recent measurements to determine whether a change in power or frequency is necessary. There are actually at least three determinations that can make use of multiple recent measurements. These include (1) determining whether the signals are fluctuating to an extent that requires a special adjustment technique, (2) determining whether an adjustment is necessary (using the special technique), and (3) determining how large of an adjustment is necessary.

Intelligent power level adjustment for cable modems in presence of noise

An flexible address translation method allows a computer network to automatically learn that a visiting node has attached and then automatically establish a virtual gateway so that the visiting node can communicate through the network with local nodes, other visiting nodes, and/or Internet sites. The network performs an address translation to enable the connectivity of the visiting node. The network maintains one or more globally unique outside addresses that point to it. When a visiting node connects to the network, the network translates the source address of packets from the node to a particular one of its outside addresses. The network also replaces destination addresses in packets received by the network that are addressed to the particular outside address. Specifically, the network replaces the globally unique outside address with the 'home' address of the visiting node.

Growing community of inventors

Milpitas, CA, United States of America

Mark E Millet