gtpc1m2w | Transmission Control Protocol/Internet Protocol |
Information about the number of messages, bytes, and packets that are sent and received is collected for each TCP/IP application. This information is provided in the reports that are generated by data collection and reduction. These counters are updated and displayed differently based on whether or not the application is defined in the TCP/IP network services database, as well as how the application is defined in the database.
The byte and packet counts are updated by the TCP/IP stack. These counts are only updated for packets that contain data. Control messages such as SYN, SYN/ACK, and stand-alone ACKs are not counted.
If an application is defined in the TCP/IP network services database and has a weight parameter specified, the input and output message counts are updated by each individual TCP/IP application. See Message Counts by Application for more information about how to gather message counts on an application-by-application basis.
If an application is not defined in the TCP/IP network services database or does not have the weight parameter specified, the input and output message counts are updated as follows:
The number of TCP/IP weighted input messages is shown in the system summary report. In addition, there is a TCP/IP weighted input messages by application report and a TCP/IP message summary report. In these reports, the count information is shown for each individual application that is defined in the TCP/IP network services database. If an application is not defined in the database, the counts for that application are shown in a single category in the report called OTHER. See TPF System Performance and Measurement Reference for more information about data collection and reduction and for an example of the reports.
If you want to gather input and output message counts on an application-by-application basis, do the following:
The weight parameter specifies a weighting factor for each message sent or received by a particular application. A value of 100 is equal to 1 message. Therefore, if you specify 50 for the weight parameter for an application, the messages for that application will count half as much. For example, if this application receives 50 messages per second, the input message count will indicate that the application received 25 weighted messages per second. Similarly, if you specify 200 for the weight parameter for an application, the messages for that application will count twice as much. For example, if this application sends 50 messages per second, the output message count will indicate that the application sent 100 weighted messages per second.
The TCP architecture does not have a single definition for a message; therefore, the definition of a message can be different for each application. For example, a single socket send can be considered to be one complete message, multiple messages, or part of a message. Use the tpf_tcpip_message_cnt function to increment the input or output message counters for your TCP/IP applications based on the definition of a message for that application. This function requires the port number and protocol of the application as input. If the application does not know the port number, the application can issue a call to the getservbyname socket API to get the port number. See the TPF C/C++ Language Support User's Guide for more information about the tpf_tcpip_message_cnt function.
The TCP/IP applications that are shipped with the TPF system (MQSeries, the TPF Internet mail servers, and so on) include calls to the tpf_tcpip_message_cnt function to increment the message counters. To count messages for these applications, you only need to define them in the TCP/IP network services database. See TCP/IP Network Services Database File Example for an example of the definitions you can add for these applications and for information about how a message is defined for each of these applications.