International Business Machines Corporation

Raymond F Bird

Marcel Mordechay Yung

Diane Phylis Pozefsky

James P Gray

Shay Kutten

Philippe A Janson

Refik A Molva

Soumitra Sarkar

Kathryn Heninger Britton

Joshua S Auerbach

Harold D Dykeman

Inder Sarat Gopal

Brad Alan Makrucki

Amir Herzberg

Willibald A Doeringer

John H Wilson

Allan K Edwards

Roger D Turner

Jeffrey G Knauth

Ralph Benjamin Case

James John Martin

Johny Mathew

Tsipora P Barzilai

Bharath K Kadaba

Yue T Yeung

Winston W Chung

Tein-Yaw D Chung

James B Kalmbach, Jr

Winston W-K Chung

A technique for adapting receiver thresholds to improve rate-based flow control in a data communications network. With this invention, the flow control process becomes self-calibrating such that threshold values are dynamically adjusted to adapt to current network conditions, without requiring user intervention. Several different indicators of network conditions are monitored, and appropriate adjustments are made to the threshold(s) upon detecting these specific indicators. One monitor enables the threshold to increase when the network is uncongested, enabling the sender to increase its transmission rate. Conversely, the threshold is lowered if the network is congested, so that the transmission rate will be decreased. Another monitor balances bandwidth allocation among connections sharing a bottleneck resource, by lowering the threshold (and therefore decreasing the send rate) when a connection uses a high share of the resource. A third monitor detects the presence of traffic from protocols not using adaptive receiver thresholds, and adjusts the threshold (including an upper and lower threshold bound) in order to compete fairly for resources with these other protocols. The monitors may be implemented individually or in combination.

Adapting receiver thresholds to improve rate-based flow control

A method and apparatus for providing authentication among a dynamically selected group of users in a communication system with a dynamically changing network topology. With this invention, freshness information and alleged identity information are transmitted from each of the users in the group using available paths in the network. A group key is then generated, and coded information, derived from the group key and the above transmitted information, is sent to each of the users. Each unit of coded information is accompanied by an identifying tag so as to identify which of the users is to use the appropriate unit of coded information. Each alleged user will then extract the group key from a corresponding coded information unit only if it shares an appropriate secret with a server. Without knowledge of the group key, a user cannot be authenticated.

Multi-party secure session/conference

A Transport Layer Protocol Boundary (TLPB) architecture is described which will permit an application program to run over a non-native transport protocol without first generating a protocol compensation package tailored to the transport protocols assumed by the program's application programming interface and by the available transport provider. All transport functions required by the program are converted to standardized or TLPB representations. When a connection between the first application program and a second remote application is requested, the individual required TLPB transport functions are compared to corresponding functions supported by the transport provider. Compensations are invoked only where there is a mismatch. The node on which the remote application program runs is informed of the compensations so that necessary de-compensation operations can be performed before the data is delivered to the remote application program.

Compensation for mismatched transport protocols in a data communications

An arrangement of authenticating communications network users and means for carrying out the arrangement. A first challenge N1 is transmitted from a first user A to a second user B. In response to the first challenge, B transmits a first response and second challenge N2 to A. A verifies the first response. A then generates and transmits a second response to the second challenge to B, where the second response is verified. The first response must be of a minimum form

Authentication protocols in communication networks

A technique called 'Adaptive Pacing' permits a receiving node, in a computing networking, to change the size of an information window during an active session. To effect the change, the receiving node sends an 'Isolated Pacing Message' (IPM) to the sending node. Thereafter, the sending node adjusts the window size to conform with a window size value in the IPM. The IPM includes a type field, a reset window indicator and a next window size field. There are three types of isolated pacing messages. Two of the messages are used by the receiving node to control the flow of data; while the third message is used, by the sending node, to confirm the beginning of a new window and the ending of an old one.

Adaptive session-level pacing

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Durham, NC, United States of America

Raymond F Bird