Michael A Fitzpatrick

US Patent:

6336193, Jan 1, 2002

Filed:

Aug 21, 1998

Appl. No.:

09/137947

Inventors:

Harry Morris Yudenfriend - Poughkeepsie NY
John Andrew Staubi - Poughkeepsie NY
Michael G. Fitzpatrick - Raleigh NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H02H 305

US Classification:

714 15, 714 2

Abstract:

Error recovery is performed when an error rate for a subsystem of a computer environment (e. g. , an Input/Output (I/O) subsystem) is greater than a predefined value and a critical resource of the computer environment (e. g. , storage) is experiencing a shortage. Error recovery may include slowing down activity of the devices associated with the subsystem and/or simulating errors for the subsystem. The simulation of the errors does not require a large block of additional storage, and thus, the shortage situation is not exacerbated.

US Patent:

6338145, Jan 8, 2002

Filed:

Aug 21, 1998

Appl. No.:

09/138104

Inventors:

Harry Morris Yudenfriend - Poughkeepsie NY
John Andrew Staubi - Poughkeepsie NY
Michael G. Fitzpatrick - Raleigh NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H02H 305

US Classification:

714 2, 714 15

Abstract:

Error recovery is performed when an error rate for a subsystem of a computer environment (e. g. , an Input/Output (I/O) subsystem) is greater than a predefined value and a critical resource of the computer environment (e. g. , storage) is experiencing a shortage. Error recovery may include slowing down activity of the devices associated with the subsystem and/or simulating errors for the subsystem. The simulation of the errors does not require a large block of additional storage, and thus, the shortage situation is not exacerbated.

US Patent:

6338151, Jan 8, 2002

Filed:

Aug 21, 1998

Appl. No.:

09/137997

Inventors:

Harry Morris Yudenfriend - Poughkeepsie NY
John Andrew Staubi - Poughkeepsie NY
Michael G. Fitzpatrick - Raleigh NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H02H 305

US Classification:

714 47, 714 15

Abstract:

Error recovery is performed when an error rate for a subsystem of a computer environment (e. g. , an Input/Output (I/O) subsystem) is greater than a predefined value and a critical resource of the computer environment (e. g. , storage) is experiencing a shortage. Error recovery may include slowing down activity of the devices associated with the subsystem and/or simulating errors for the subsystem. The simulation of the errors does not require a large block of additional storage, and thus, the shortage situation is not exacerbated.

US Patent:

6657974, Dec 2, 2003

Filed:

Apr 14, 2000

Appl. No.:

09/549946

Inventors:

Edward Glen Britton - Chapel Hill NC
Michael G. Fitzpatrick - Raleigh NC
Jeffrey Douglas Haggar - Holly Springs NC
Maurice Isrel, Jr. - Raleigh NC
Thomas Donald Moore - Raleigh NC
Andrew Henry Richter - Raleigh NC
Barton Clark Vashaw - Apex NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04L 1228

US Classification:

370255, 370475, 370401, 370389

Abstract:

The invention ensures that a single and consistent reply is made to ARP requests in a system of connected IP networks in which each host can contain combinations of host adapters, offload adapters and virtual IP addresses.

US Patent:

6675206, Jan 6, 2004

Filed:

Apr 14, 2000

Appl. No.:

09/549291

Inventors:

Edward Glen Britton - Chapel Hill NC
Michael G. Fitzpatrick - Raleigh NC
Jeffrey Douglas Haggar - Holly Springs NC
Maurice Isrel, Jr. - Raleigh NC
Andrew Henry Richter - Raleigh NC
Barton Clark Vashaw - Apex NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 15177

US Classification:

709220, 709222, 709223, 709226, 709227, 709228, 709245

Abstract:

The invention ensures that a single and consistent reply is made to an ARP request in a system of connected IP networks. When an adapter becomes active, the relative network on which it resides is determined by transmitting control packets over it and all other adapters known to the host and observing if and where responses are returned to the adapters. One adapter on a network is designated as active. If the same network contains other adapters, they are marked as standby adapters for the purpose of responding to ARP messages. Special processing is provided for offload adapters that perform there own ARP processing.

US Patent:

6697326, Feb 24, 2004

Filed:

Apr 14, 2000

Appl. No.:

09/549945

Inventors:

Edward Glen Britton - Chapel Hill NC
Michael G. Fitzpatrick - Raleigh NC
Jeffrey Douglas Haggar - Holly Springs NC
Maurice Isrel, Jr. - Raleigh NC
Barton Clark Vashaw - Apex NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04L 1226

US Classification:

370218, 370257, 37039554

Abstract:

The invention ensures that a single and consistent reply is made to ARP request in a system of connected IP networks. In each host, the first adapter A to become active is designated as being in an arbitrary first physical network (PNET ). For each subsequent adapter B to become active on a host, the host sends a packet over one of the adapters (A) of each network already known to the host with a hop count of one. If the packet is received over adapter B, it is known that adapters A and B are in the same physical network. If this occurs, adapter B is marked as being in the same network PNET as adapter A. If the packet is not received over adapter B then B is in a different physical network as A. In this event, adapter B is marked as being in a new network PNET. When adapter A becomes inactive, if there are other active adapters in the physical network to which A belongs, then one of the remaining adapters B in that physical network is designated to have the responsibility for replying to ARP requests for A.

US Patent:

7272139, Sep 18, 2007

Filed:

Jan 11, 2002

Appl. No.:

10/045559

Inventors:

Michael G. Fitzpatrick - Raleigh NC, US
Jeffrey Douglas Haggar - Holly Springs NC, US
Bala Rajaraman - Cary NC, US
Arthur James Stagg - Raleigh NC, US
Jerry Wayne Stevens - Raleigh NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04J 3/16

US Classification:

370392, 370469

Abstract:

Methods, systems, and computer program products for improving data transfer in complex computing environments. Internal routing enhancements are defined, which enable traffic of virtual servers to be processed more efficiently, thereby improving overall data transfer rates. Instead of performing routing operations in the Internet Protocol (“IP”) layer of a networking stack, a “mini-routing” table is created programmatically and is used to perform routing at the Data Link Control (“DLC”) layer. This technique avoids bottlenecks in the IP layer and speeds the data transfer process.

US Patent:

8036105, Oct 11, 2011

Filed:

Aug 8, 2005

Appl. No.:

11/199305

Inventors:

Andrew H. Arrowood - Raleigh NC, US
Michael G. Fitzpatrick - Raleigh NC, US
Constantinos Kassimis - Cary NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 11/07

US Classification:

370217, 370244

Abstract:

A solution for monitoring a problem condition in a communications system is provided. A communications protocol implementation monitors the communications system for the problem condition. The communications protocol implementation can initiate a response based on the problem condition being present. In this manner, the communications protocol implementation provides an effective monitor for detecting and/or recovering from a problem condition in the communications system.