David M Mcghee

US Patent:

6389065, May 14, 2002

Filed:

Dec 6, 1999

Appl. No.:

09/455547

Inventors:

David Wesley McGhee - Austin TX

Assignee:

Cisco Technology Inc. - San Jose CA

International Classification:

H04L 500

US Classification:

375222, 375225, 375227, 370252, 370465, 455 69

Abstract:

A rate adaptive digital subscriber line (XDSL) communication system and method are disclosed. An XDSL link for XDSL equipment is trained at a data rate set by a baud rate and a constellation size. Actual operating characteristics of the XDSL equipment are then obtained from parameters for the trained XDSL link. One or more rate adaptive data tables storing empirical data for performance of the XDSL equipment are accessed. Then, it is determined whether the trained data rate will provide a desired bit error rate using the actual operating characteristics and the empirical data from the accessed one or more of the rate adaptive data tables. In one embodiment, if the trained data rate will not provide the desired bit error rate, a new data rate is selected using the empirical data and the actual operating characteristics. Then, the XDSL link is trained using the new data rate, and the process is repeated. Further, in one embodiment, the actual operating characteristics used comprise the actual receiver gain and signal-to-noise ratio, and the empirical data comprises specified receiver gains, signal-to-noise ratios, baud rates and constellation sizes used to achieve a desired bit error rate.

US Patent:

6553075, Apr 22, 2003

Filed:

Jan 12, 1999

Appl. No.:

09/228686

Inventors:

David W. McGhee - Austin TX
James R. Sisk - Cedar Park TX

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04B 110

US Classification:

375254, 375222, 375225, 370468, 379 103

Abstract:

A system to analyze and compensate for noise on a transmission line ( ) is provided. The system comprises a transmission card which includes a transceiver ( ), and a microprocessor ( ) attached to the transceiver ( ). The system also comprises a transmission line ( ) coupled to the transceiver ( ) and at least one customer premise equipment ( ) coupled to the transceiver ( ) by the transmission line ( ). The microprocessor ( ) is operable to monitor the transmission line ( ) and determine the signal-to-noise ratio on the line as a function of frequency, and adjust the rate of transmission in terms of bandwidth in terms of bits as a function of frequency.

US Patent:

6658049, Dec 2, 2003

Filed:

Jan 12, 1999

Appl. No.:

09/228688

Inventors:

David W. McGhee - Austin TX
Richard L. House - Round Rock TX

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04B 1702

US Classification:

375211, 375222, 370492

Abstract:

A system for repeating an xDSL signal ( ) is disclosed. The system comprises a receiver ( ) operable to receive the xDSL signal ( ), a first analog front end ( ) coupled to the receiver ( ) and operable to convert the xDSL signal to a digital signal, and a series of digital signal processors ( ) coupled to the first analog front end ( ) and operable to remove noise elements from the digital signal. Also provided is a second analog front end ( ) coupled to the second digital signal processor ( ) and operable to convert the digital signal back to the analog domain. A driver circuit ( ) is operable to increase the signal strength of the analog signal and retransmits it over a new length of wiring.

US Patent:

8462781, Jun 11, 2013

Filed:

Apr 6, 2011

Appl. No.:

13/080906

Inventors:

David W. McGhee - Austin TX, US
Stefan Johansson - Round Rock TX, US
Shardendu Pandey - Cedar Park TX, US
Keith E. Chaney - Austin TX, US

Assignee:

Anue Systems, Inc. - Austin TX

International Classification:

H04L 12/28
H04L 12/56

US Classification:

370389, 370390, 370392

Abstract:

Systems and methods are disclosed for in-line removal of duplicate network packets in network packet streams operating at high speeds (e. g. , 1-10 Gbps and above). A hash generator applies at least one hash algorithm to incoming packets to form one or more different hash values. The packet deduplication systems and methods then use the one or more hash values for each incoming packet to identify data stored for previously received backs and use the identified data to determine if incoming packets are duplicate packets. Duplicate packets are then removed from the output packet stream thereby reducing duplicate packets for downstream processing. A deduplication window can further be utilized to limit the amount of data stored for previous packets based upon one or more parameters, such as an amount of time that has passed and/or a number of packets for which data has been stored. These parameters can also be selected, configured and/or adjusted to achieve desired operational objectives.

US Patent:

59995408, Dec 7, 1999

Filed:

Dec 22, 1998

Appl. No.:

9/219148

Inventors:

David Wesley McGhee - Austin TX

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04D 100

US Classification:

370465

Abstract:

A rate adaptive digital subscriber line (XDSL) communication system and method are disclosed. An XDSL link for XDSL equipment is trained at a data rate set by a baud rate and a constellation size. Actual operating characteristics of the XDSL equipment are then obtained from parameters for the trained XDSL link. One or more rate adaptive data tables storing empirical data for performance of the XDSL equipment are accessed. Then, it is determined whether the trained data rate will provide a desired bit error rate using the actual operating characteristics and the empirical data from the accessed one or more of the rate adaptive data tables. In one embodiment, if the trained data rate will not provide the desired bit error rate, a new data rate is selected using the empirical data and the actual operating characteristics. Then, the XDSL link is trained using the new data rate, and the process is repeated. Further, in one embodiment, the actual operating characteristics used comprise the actual receiver gain and signal-to-noise ratio, and the empirical data comprises specified receiver gains, signal-to-noise ratios, baud rates and constellation sizes used to achieve a desired bit error rate.

US Patent:

20180048543, Feb 15, 2018

Filed:

Oct 24, 2017

Appl. No.:

15/791997

Inventors:

- Singapore, SG
David W. McGhee - Austin TX, US

International Classification:

H04L 12/26
H04L 12/939

Abstract:

Traffic differentiator systems for network devices and related methods are disclosed that include automatic port order determination. The disclosed embodiments includes input ports that receive a first stream of packets and a second stream of packets and a packet difference processor that operates in a learning mode and a normal mode. In the learning mode of operation, the packet difference processor automatically determines a port order representing whether the first stream of packets for the first port or the second stream of packets for the second port represents a first in time version of received packets. In the normal mode of operation, the packet difference processor uses the port order determination to facilitate determination of difference packets between the first stream of packets and the second stream of packets.

US Patent:

20150215176, Jul 30, 2015

Filed:

Dec 15, 2014

Appl. No.:

14/570058

Inventors:

- Austin TX, US
David W. McGhee - Austin TX, US

International Classification:

H04L 12/26

Abstract:

Traffic differentiator systems for network devices and related methods are disclosed that include automatic port order determination. The disclosed embodiments includes input ports that receive a first stream of packets and a second stream of packets and a packet difference processor that operates in a learning mode and a normal mode. In the learning mode of operation, the packet difference processor automatically determines a port order representing whether the first stream of packets for the first port or the second stream of packets for the second port represents a first in time version of received packets. In the normal mode of operation, the packet difference processor uses the port order determination to facilitate determination of difference packets between the first stream of packets and the second stream of packets.

US Patent:

20150215222, Jul 30, 2015

Filed:

Jan 27, 2014

Appl. No.:

14/164450

Inventors:

- Austin TX, US
David W. McGhee - Austin TX, US
Shardendu Pandey - Cedar Park TX, US
Cary J. Wright - Austin TX, US
Scott Register - Austin TX, US

Assignee:

Anue Systems, Inc. - Austin TX

International Classification:

H04L 12/823
H04L 12/841

Abstract:

Traffic differentiator systems for network devices and related methods are disclosed that determine difference packets from multiple packet streams. Some embodiments are configured to receive two streams of packets with one stream being a processed version of another stream and then to determine difference packets within a lookup time window that is, for example, associated with a processing time for the second stream to be a processed version of the first stream. Difference packets within a lookup time window can also be determined for packets received within a single combined stream of packets. Difference packets and/or related statistical information is then output for additional processing, as desired. The streams of packets can be associated with ingress and egress packets for a network device, and the difference packets and related statistical information can be used to determine packets that are removed, added, and/or modified by the network device.