International Business Machines Corporation

Ketan Priyakant Pancholi

Venkat Venkatsubra

Dwip N Banerjee

Kavitha Vittal Murthy Baratakke

Deanna Lynn Quigg Brown

Ranadip Das

Radhika Chirra

Vinit Jain

Vasu Vallabhaneni

A dynamically-enforceable application-controlled quasi-reliable extension to TCP permits a client application to dynamically set a percent loss tolerance for data transmission reliability through network input/output system calls to the TCP, thereby programming the transport layer to optimistically acknowledge non-critical missing frames. The reliability requirement can be dynamically set within TCP to the level of reliability required for specific data frames within the data stream during the data transfer. Based on this loss tolerance specified, the TCP layer makes a determination whether to trigger a retransmission or continue delivering out-of-order frames to the application. A forced acknowledgement frame is sent for each missing packet until the number missing packets causing forced acknowledgments within the current receive buffer frame exceeds the loss tolerance. This process avoids needless retransmissions and permits the TCP data flow and sliding window to advance uninterrupted, thereby providing substantial performance benefits to network throughput.

Method, system and article for client application control of network transmission loss tolerance

Determining availability of a destination for computer network communications that include providing on a caching device a destination availability cache comprising at least one cache entry representing availability of a destination and providing, from the caching device to a source, through computer network communications, information indicating the availability of the destination. In typical embodiments, the cache entry comprises a network address of a destination device and a time limitation for the cache entry.

Determining availability of a destination for computer network communications

A method in a data processing system for reducing the learning curve of a transmission control protocol connection. A domain name system is queried for information. The information and a previously used transmission control protocol parameter for a transmission control protocol connection are received from the domain name system. The information and the previously used transmission control protocol parameter are used to configure a current transmission control protocol connection.

Reducing the learning curve of a transmission control protocol connection

The present invention provides a method and apparatus for handling reordered data packets. A method comprises receiving a data packet and determining if the data packet is received out of order. The method further comprises delaying transmission of an acknowledgement indicating that a data packet is missing in response to determining that the data packet is received out of order.

Method and apparatus for handling reordered data packets

A method, system, and computer program product for optimizing a message size for communication in a communication network are disclosed. The method comprises identifying a connection to a target, sending to a path maximum transmission unit value server (which is not the target) a request for a path maximum transmission unit value for the connection to the target, and, in response to receiving the path maximum transmission unit value for the connection to the target from the server, optimizing a communication by sending to the target a packet having a size in accordance with the value.

Remote discovery and storage of a path maximum transmission unit (PMTU) value

The present invention provides a method and apparatus for discovering a path maximum transmission unit. The method comprises receiving a data packet from a first remote device for transmission to a second remote device and determining if a size of the received data packet is greater than a maximum transmission unit (MTU) value. In response to determining that the size of the received data packet is greater than the MTU value, the method further comprises transmitting a portion of the received data packet to the second remote device and transmitting a message to the first remote device indicating that the size of the received data packet exceeds the MTU value.

Method and apparatus for discovering path maximum transmission unit (PMTU)

The server side Transfer Control Protocol is modified so that the server returns a SYNACK message with the window size equal to zero if the server is busy. When a client sends a TCP connection request and receives a synchronization acknowledgement message with the window size equal to zero, the client knows that the server received the connection request and that the server is busy. The client may then send an acknowledgement message to complete the three-way synchronization handshake, thus successfully completing the connection. Thereafter, the client side TCP may probe the server side TCP until a window update message is received from the server. When the server sends a window update message to set the window size to a non-zero size, the client knows that the server is no longer busy and the client application may then use the TCP connection.

Method, apparatus, and program for informing a client when a server is busy in the transfer control protocol

The present invention provides a method for handling reordered data packets. A method comprises receiving a data packet and determining if the data packet is received out of order. The method further comprises delaying transmission of an acknowledgement indicating that a data packet is missing in response to determining that the data packet is received out of order.

Growing community of inventors

Austin, TX, United States of America

Ketan Priyakant Pancholi