KN3 TCP Counter Statistics Attributes

Use the KN3 TCP Counter Statistics attributes to view TCP protocol statistics for the selected the TCP/IP stack on a z/OS v1r12 or later system.

Collection Time The time and date at which status information was collected. This time is displayed in the following format:

mm/dd/yy hh:mm:ss

Where:

The stored format is a string no longer than 16 characters in the format CYYMMDDHHMMSSmmm (as in 1020315064501000 for 03/15/02 06:45:01) where:

Connections Established The number of TCP connections for which the current state is either ESTABLISHED or CLOSE-WAIT since TCP/IP initialization. The format is an unsigned integer.

Origin Node An internal node name used to identify the system from which this row of data was obtained since TCP/IP initialization. The format is an alphanumeric string no longer than 32 characters.

Out-of-Order Segments Percentage The percentage of segments received that was out-of order over during the most recent sampling interval compared to the total number of segments transmitted. The format is an integer between 1 and 100 inclusive.

Receive Segment Rate The number of segments received per minute during the most recent sampling interval. The format is an unsigned integer.

Received Segment Error Rate The rate at which segments in error were received during the most recent sampling interval. The format is an unsigned integer.

Segment Retransmission Rate The rate at which TCP segments were retransmitted during the most recent sampling interval. The format is an unsigned integer.

System ID The SMF system ID. The format is an alphanumeric string no longer than 4 characters. This field is not displayed.

TCPIP STC Name The name of the TCP/IP job. The format is an alphanumeric string no longer than 8 characters.

Total Accepted Connections The number of binary TCP connections accepted by all listening applications since TCP/IP initialization. The format is an unsigned long long integer.

Total ACKs with Header Prediction The number of binary input TCP acknowledgements with successful header prediction since TCP/IP initialization. The format is an unsigned integer.

Total Active Socket OPENs The number of TCP connections that have made a direct transition to the SYN-SENT state from the CLOSED state since TCP/IP initialization. The format is an unsigned integer.

An Active OPEN means that during TCP connection setup, the client process that is using TCP takes the active role and initiates the connection by sending a TCP SYN message to start the connection. The opposite is a Passive OPEN where a TCP application listens for clients.

Total All Data After Window The number of binary input TCP segments with all data after the current window since TCP/IP initialization. The format is an unsigned integer.

Total All Data Before Window The number of binary input TCP segments with all data before the current window, indicating that the segment contains duplicate data since TCP/IP initialization. The format is an unsigned integer.

Total Attempt Failures The number of TCP connections that have made a direct transition to the CLOSED state from either the SYN-SENT state or the SYN-RCVD state, plus those that have made a direct transition to the LISTEN state from the SYN-RCVD state since TCP/IP initialization. The format is an unsigned integer.

Total BulkData AIQ Segments The number of binary input TCP segments that are received over the BulkData Ancillary Input Queue (AIQ) when using the queued direct I/O (QDIO) inbound workload queueing function since TCP/IP initialization. The format is an unsigned long long integer.

Total Connections Closed The number of TCP connections with a socket that has been closed since TCP/IP initialization. The format is an unsigned integer.

Total Data Segments Predicted The number of binary input TCP data segments with successful header prediction since TCP/IP initialization. The format is an unsigned integer.

Total Delayed Output ACKs The number of binary delayed output TCP acknowledgements since TCP/IP initialization. The format is an unsigned integer.

Total Discards for Bad Checksum The number of binary input TCP segments discarded due to a bad checksum since TCP/IP initialization. The format is an unsigned integer.

Total Discards for Bad Length The number of binary input TCP segments discarded due to a bad header length since TCP/IP initialization. The format is an unsigned integer.

Total Discards for Length Too Short The number of input TCP segments discarded due to the data length being shorter than the segment length since TCP/IP initialization. The format is an unsigned integer.

Total Discards for Old Time Stamp The number of input TCP segments discarded due to old time stamps since TCP/IP initialization. The format is an unsigned integer.

Total Duplicate ACKs The number of binary input duplicate TCP acknowledgements (ACKs) since TCP/IP initialization. The format is an unsigned integer.

Total Established Resets The number of TCP connections that have made a direct transition to the CLOSED state from either the ESTABLISHED state or the CLOSE-WAIT state since TCP/IP initialization. The format is an unsigned integer.

Total FINWAIT2 Drops The number of binary TCP connections dropped due to the FINWAIT2 timer expiring beforereceiving FIN segments since TCP/IP initialization. The format is an unsigned integer.

When a socket is closed abnormally (for example, no longer needed) it is not made available immediately. Instead it is placed into a state called FINWAIT2 (which is what shows up in the netstat -s command). It waits there for a period of time before it is made available in the free pool. The default for this is 600 seconds.

Total Flow Controls The sum of Input Window Probes, Input Window Updates, Output Window Probes, and Output Window Updates since TCP/IP initialization. The format is an unsigned long long integer.

Total Input After Closed The number of binary input TCP segments received after the corresponding sockets have been closed since TCP/IP initialization. The format is an unsigned integer.

Total Input Segments Received The number of input TCP segments received, including those received in error, since TCP/IP initialization. The format is an unsigned long long integer.

Total Input Window Probes The number of binary input TCP segments processed while the current receive window size is zero since TCP/IP initialization. The format is an unsigned integer.

Total Input Window Updates The number of binary input TCP segments that change only the receive window size since TCP/IP initialization. The format is an unsigned integer.

Total Keepalive Drops The number of binary TCP connections dropped due to no response while sending keepalive probe requests since TCP/IP initialization. The format is an unsigned integer.

Total Keepalive Probes The number of binary output TCP keepalive probe requests since TCP/IP initialization. The format is an unsigned integer.

Total Out-of-Order Segments The number of binary input TCP segments that did not contain the next expected sequence number since TCP/IP initialization. The format is an unsigned integer.

Total Output RSTs The number of binary TCP segments sent containing the TCP/IP reset (RST) flag since TCP/IP initialization. The format is an unsigned integer.

Total Output Segments Sent The number of binary output TCP segments sent since TCP/IP initialization. The format is an unsigned long long integer.

Total Output Window Probes The number of binary output window probe requests since TCP/IP initialization. The format is an unsigned integer.

Total Output Window Updates The number of binary output TCP segments that change only the receive window size since TCP/IP initialization. The format is an unsigned integer.

Total Passive Drops The number of passive TCP connection requests discarded since TCP/IP initialization. The format is an unsigned integer.

Total Passive Socket OPENs The number of TCP connections that have made a direct transition to the SYN-RCVD state from the LISTEN state since TCP/IP initialization. The format is an unsigned integer.

A Passive OPEN is where a TCP application listens for clients. The opposite is an Active OPEN, which means that during TCP connection setup, the client process that is using TCP takes the active role and initiates the connection by actually sending a TCP message to start the connection, a SYN message.

Total PMTU Errors The number of binary TCP connections that exceeded the path maximum transmission unit (MTU) discovery retransmit threshold since TCP/IP initialization. The format is an unsigned integer.

Total PMTU Retransmits The number of binary TCP segments retransmitted due to path maximum transmission unit (MTU) discovery since TCP/IP initialization. The format is an unsigned integer.

Total Retransmission Percentage The percentage of TCP segments that required retransmission compared to the total number of segments transmitted since TCP/IP initialization. The format is an integer between 1 and 100 inclusive.

Total Retransmit Drops The number of binary TCP connections dropped due to the retransmit threshold being exceeded since TCP/IP initialization. The format is an unsigned integer.

Total Retransmit Timeouts The number of binary TCP retransmit timer pops since TCP/IP initialization. The format is an unsigned integer.

Total Segments Discarded The number of input TCP segments discarded since TCP/IP initialization. This attribute provides the count of all discarded segments. Other attributes provide more granular counters for some of the reasons that segments were discarded. The format is an unsigned long long integer.

Total Segments Retransmitted The number of binary TCP segments retransmitted since TCP/IP initialization. The format is an unsigned integer.

Total Some Data After Window The number of binary input TCP segments with some data after the current window since TCP/IP initialization. The format is an unsigned integer.

Total Some Data Before Window The number of binary input TCP segments with some data before the current window, indicating that the segment contains some duplicate data since TCP/IP initialization. The format is an unsigned integer.

Total Timewait Reused The number of TCP connections in the TIMEWAIT state that have been reused for connections in the SYN-RCVD state since TCP/IP initialization. The format is an unsigned integer.

Total Window Probe Drops The number of binary TCP connections dropped due to no response while sending window probe requests since TCP/IP initialization. The format is an unsigned integer.

Transmit Segment Rate The number of segments transmitted per minute during the most recent sampling interval since TCP/IP initialization. The format is an unsigned integer.