Philip Mark Robinson

US Patent:

6351773, Feb 26, 2002

Filed:

Dec 21, 1998

Appl. No.:

09/217534

Inventors:

John G. Fijolek - Naperville IL
Levent Gun - Lake Forest IL
Ronald B. Lee - Northbrook IL
Philip T. Robinson - Barrington IL

Assignee:

3Com Corporation - Santa Clara CA

International Classification:

G06F 1100

US Classification:

709228, 709222, 370 19

Abstract:

Methods for providing restricted access for a network device such as a cable modem or customer premise equipment on a data-over-cable system. An unknown or new network device is assigned a restricted network address such as a restricted Internet Protocol address. The restricted network address allows the network device to access less than all of the available features on the data-over-cable system. A connection timer is started on the data-over-cable system for a restricted connection to the network device. The connection timer restricts access to the data-over-cable system over a timed interval. A restricted connection is created between the data-over-cable system and the network device including the temporary restricted network address and the connection timer, thereby providing restricted access to the data-over-cable system over a timed interval. The methods may allow a data-over-cable system to provide restricted connections to unknown or new network devices without a long delay, yet provide security to the data-over-cable system.

US Patent:

6577642, Jun 10, 2003

Filed:

Jan 15, 1999

Appl. No.:

09/232762

Inventors:

John G. Fijolek - Naperville IL
Nurettin B. Beser - Evanston IL
Philip T. Robinson - Lake Barrington IL
Levent Gun - Lake Forest IL

Assignee:

3Com Corporation - Santa Clara CA

International Classification:

H04J 316

US Classification:

370465

Abstract:

A method and system for virtual network administration with a data-over-cable system. A virtual networking tag and a network address (e. g. , an Internet Protocol address) assigned by a network other than a data-over-cable system is used to provide a virtual network to one or more network devices, such as cable modems via a data-over-cable system. The virtual networking tag may also be used to request a desired service class (e. g. , Class-of-Service, Quality-of-Service, Type-of-Service, Service Level Agreements, etc. ), for a desired end-to-end networking service (e. g. , Voice over Internet Protocol). The virtual networking tag can be mapped to a data-over-cable service class. The data-over-cable service class can be mapped into a transport service class for a transport network. The virtual networking tag is used to provide a desired end-to-end networking service from a network device on a first external network (e. g. , an Ethernet Local Area Network), through the data-over-cable system, through a transport network (e. g.

US Patent:

6804262, Oct 12, 2004

Filed:

Apr 28, 2000

Appl. No.:

09/560087

Inventors:

Mark O. Vogel - Hampshire IL
Philip T. Robinson - Barrington IL

Assignee:

3Com Corporation - Marlborough MA

International Classification:

H04J 100

US Classification:

370480, 370281, 370302, 370343

Abstract:

In a data-over-cable system, a cable head-end transmits a signal that includes a plurality of analog television signal components an at least one quadrature amplitude modulated (QAM) digital signal component, the signal components being defined by frequency channels. A cable modem has a tunable frequency selection system, operable at a first bandwidth, corresponding to the bandwidth of the frequency channels, and at a second, substantially narrower bandwidth, that provides a filtered signal and a power measurement system that measures the power level of the filtered signal. The frequency selection system scans through the channels, operating at its second bandwidth, and, in each channel, tunes to a first frequency and a second frequency. The power levels of the filtered signals from the first and second frequencies are measured and compared to distinguish the QAM digital signal components from the other signal components.

US Patent:

7089580, Aug 8, 2006

Filed:

Mar 29, 2000

Appl. No.:

09/538342

Inventors:

Mark O. Vogel - Hampshire IL, US
Philip T. Robinson - Lake Barrington IL, US

Assignee:

3Com Corporation - Santa Clara CA

International Classification:

H04N 7/173

US Classification:

725111, 725119, 725127

Abstract:

Methods for improved cable modem ranging in a data-over-cable system. One method includes receiving a value that characterizes how equipment in the network is configured. Using this characteristic value, a cable modem may estimate loss in its upstream path from a measurement of a downstream signal and thereby estimate its initial transmit level during ranging. Launching at a proper initial transmit level may ensure that range request messages arrive at the cable modem termination system with sufficient strength to be detected and hence ameliorate ranging. Another method collects difference between these estimated initial transmit levels and the final transmit levels that succeeded in evoking a response from the cable modem termination system. The collected differences are analyzed and the result of the analysis is passed to cable modems to adjust their estimated initial transmit levels. These methods may shorten a cable modem's time for ranging and may decrease collisions on the upstream path when many cable modems try to range simultaneously.

US Patent:

60187670, Jan 25, 2000

Filed:

Feb 24, 1998

Appl. No.:

9/028404

Inventors:

John G. Fijolek - Naperville IL
Ronald B. Lee - Northbrook IL
Philip T. Robinson - Barrington IL
Levent Gun - Lake Forest IL

Assignee:

3Com Corporation - Santa Clara CA

International Classification:

G06F 1300
H04N 7173

US Classification:

709218

Abstract:

A method and system for managing network services such as subscription services from a cable modem in a data-over-cable system. The cable modem receives an initialization message on a cable television connection indicating what services are available on a data network. The cable modem uses a connection to a public switched telephone network in the data-over-cable system to send requests to and receive responses from the data network. A telephony remote access concentrator on the public switched telephone network provides an additional security mechanism by not allowing a cable modem to subscribe to unauthorized services. Using the public switched telephone network does not compromise the security of the cable television network. In addition, the public switched telephone network is used to provide administrative support to the cable television network on lower bandwidth connections by providing an administrative pathway outside of the higher bandwidth cable television connections.

US Patent:

60584211, May 2, 2000

Filed:

Feb 4, 1998

Appl. No.:

9/018784

Inventors:

John G. Fijolek - Naperville IL
Nurettin B. Beser - Evanston IL
Philip T. Robinson - Barrington IL

Assignee:

3Com Corporation - Santa Clara CA

International Classification:

G06F 15173

US Classification:

709225

Abstract:

A method and system are provided to allow a cable modem to discover an address of a network host interface on a cable television network to connect the cable modem to a data network (e. g. , the Internet). The cable modem is used in a data-over-cable system with telephony return. The cable modem is connected to a cable television network over a downstream cable data channel and connected to a public switched telephone network over a serial telephone line. The method provides a way for the cable modem to determine the address of network host interfaces (e. g. , Internet Protocol hosts) available on the cable television system via the upstream channel connected to public switched telephone network. The method includes using existing Dynamic Host Configuration Protocol ("DHCP") messages and message fields to discover network host interfaces available on the cable television system even though the cable modem only has downstream connection from the cable television network. The method and are used without changes to DHCP and can also be used in a data-over-cable system without telephony return.