Ronald S Kolb

US Patent:

61785318, Jan 23, 2001

Filed:

Dec 18, 1998

Appl. No.:

9/216340

Inventors:

Ronald E. Kolb - Lexington SC

Assignee:

NCR Corporation - Dayton OH

International Classification:

G06F 1100

US Classification:

714715

Abstract:

A method for remotely testing transmission line conditions in a token ring network. The method includes the steps of (1) generating at a remote station a series of test patterns simulating different frequency signals; (2) writing each test pattern into a token ring packet frame; (3) successively transmitting said test patterns from the remote station through a router connected to said token ring network to a receiving station on said token ring network; (4) measuring the time required for each transmitted test pattern to be successfully transmitted from the sending station to the receiving station; (5) comparing the transmission times measured for all successful test pattern transmissions; and (6) determining that a marginal transmission line condition exists within the token ring network when the transmission time associated with one of the test patterns greatly exceeds the transmission times associated with the other test patterns. The generated test patterns each comprise a differential Manchester encoded signal including a series of "one" and "zero" data values, modified so that signal state transitions corresponding to zero data values are delayed to occur at the very end of the first half of the bit period associated with the zero data value. These patterns include the following sequences: 1111111111111111. . .

US Patent:

62370421, May 22, 2001

Filed:

Dec 18, 1998

Appl. No.:

9/216352

Inventors:

Ronald E. Kolb - Lexington SC

Assignee:

NCR Corporation - Dayton OH

International Classification:

G06F 1300

US Classification:

709251

Abstract:

A method for identifying marginal transmission line conditions in a token ring network. The method includes the steps of (1) generating a series of test patterns simulating different frequency signals; (2) writing each test pattern into a token ring packet frame; (3) successively transmitting said test patterns from a sending station connected to said token ring network to a receiving station on said token ring network; (4) measuring the time required for each transmitted test pattern to be successfully transmitted from the sending station to the receiving station; (5) comparing the transmission times measured for all successful test pattern transmissions; and (6) determining that a marginal transmission line condition exists within the token ring network when the transmission time associated with one of the test patterns greatly exceeds the transmission times associated with the other test patterns. The generated test patterns each comprise a differential Manchester encoded signal including a series of "one" and "zero" data values, modified so that signal state transitions corresponding to zero data values are delayed to occur at the very end of the first half of the bit period associated with the zero data value. These patterns include the following sequences: 1111111111111111. . .