International Business Machines Corporation

Albert Ing

Thomas Anthony Gregg

Gregory Francis Pfister

Patrick John Sugrue

Joseph M Hoke

Chin Lee

Stephen R Burrow

Diagnosing communications between computer systems includes sending a message from a sending node to a receiving node. The receiving node detects an error in the receiving node receiving the message and captures the data regarding the error on the receiving. A diagnostic log request is sent from the receiving node to the sending node, the diagnostic log request including a request for the sending node to log information. The sending node diagnoses the communications error in response to the diagnostic log response.

Diagnosing communications between computer systems

A method for diagnosing communications includes sending a message from a sending node to a receiving node. The sending node detects an error in the receiving node receiving the message. A force log request is sent from the sending node to the receiving node, the force log request including a request for the receiving node to log information. A force log response is received from the receiving node at the sending node, the force log response including the logged information. The sending node diagnoses the communications error in response to the force log response.

Method, system and computer program product for diagnosing communications

A method for communication of offline status between nodes includes detecting an impending deactivation of a physical port and sending a message from a sending node to a receiving node notifying the receiving node of the impending deactivation of the physical port. The method further includes deactivating the report of any error for the physical port and sending a response from the sending node to the receiving node verifying that deactivation of the physical port.

Communication of offline status between computer systems

A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect header bits in the frame that identify the buffer set and the frame type. In this case, the entire frame is lost and the operation usually results in a timeout of the operation. By using this state information some of these lost frames can be recovered avoiding the lengthier timeout recovery procedure.

Recovery of lost frames in a communication link

A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each outstanding request for each buffer set is individually timed to detect lost frames, and each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect only the information field and there is enough information in the header to identify the frame. A request can then be sent back to the other end of the fibers to retransmit the frame. In some instances, the frame cannot be retransmitted because the content of the data may have been changed by other operations in the systems. To speed recovery in these situations, the requester of the retransmitted frame sets a much shorter timer while waiting for the response since the retransmitted frame will be sent quickly, if at all.

Shortened timeout period during frame retry in a communication link

A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect only the information field and there is enough information in the header to identify the frame. A request can then be sent back to the other end of the fibers to retransmit the frame. Certain information in the frame header is not used to identify the frame, but is used to control the transfer of frames and identify lost frames. When a frame information field is damaged by transmission errors, this header information is retained by the receiver of the damaged frame. Retaining this information at the receiver of the damaged frame frees the sender for storing it during the transmission of each frame. Freeing the sender improves performance by removing steps for the normal error free transmission of frames.

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Wappingers Falls, NY, United States of America

Albert Ing