Mark E Schreiter

US Patent:

54694361, Nov 21, 1995

Filed:

Sep 24, 1992

Appl. No.:

7/950629

Inventors:

James M. Brandner - Rochester MN
Robert J. Manulik - Rochester NY
Arthur J. Meyer - Oronoco MN
Mark E. Schreiter - Rochester MN

International Classification:

H04J 316

US Classification:

370 852

Abstract:

A large communications network is linked to a primary terminal and a secondary terminal. The primary polls the secondary whenever it has data to send, and need not poll at any maximum fixed interval. The poll operation sends a sequence of data frames to the secondary, and causes the secondary to return to the primary a sequence of frames containing any data it may have ready. The secondary can only send data to the primary in response to a poll operation; however, the secondary has the capability of sending a uniquely identifiable frame on its own initiative whenever it has data ready to send and has not received a poll. This frame causes the primary to initiate a normal poll even though it has no data ready to send.

US Patent:

59387319, Aug 17, 1999

Filed:

Jun 23, 1997

Appl. No.:

8/880777

Inventors:

Mark Eugene Schreiter - Rochester MN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04L 1200

US Classification:

709227

Abstract:

A method of automatically adjusting the line speed for communication between a client having data communications equipment (DCE) and a server having data terminal equipment (DTE). A first connection is established between the client and the server at a first speed, and the client sends a first synchronous data link control (SDLC) frame that identifies a requested speed. The server than sends a second SDLC frame in response to the first SDLC frame, identifying a second speed, wherein the second speed is the smaller of the requested speed and a predetermined (maximum) speed. If the client determines to communicate at the second speed, it drops the first connection, establishes a second connection at the second speed, and sends a third SDLC frame at the second speed; the server then sends a fourth SDLC frame in response to the third SDLC frame at the second speed, to confirm the connection, and data transmission follows. If either the client or the server does not receive an SDLC frame at the second speed within a predetermined time, it drops the second connection and establishes a third connection using the first speed.