52.23.9 Start IP Sniffing

Starts capture of IP packets.
Note that you do not have to use this command to obtain the data required for KPIs; such data is collected automatically. Compare chapter "Key Performance Indicators – KPIs".
IP sniffing data is presented in the "IP Protocol Reports" message window. A large number of protocols are supported, as detailed in the description of the window just linked to.

Configuration property:

Client:

PC: The TEMS Investigation built-in IP sniffer is used.

On-device: An on-device IP sniffing service is used.

Packet Size: Determines how many bytes of each message will be presented. If you choose a fixed packet size, any further bytes in the message will be truncated. If you choose Full packet size, all messages are presented in full and the entire header is always decoded. (For an on-device client, 1500 bytes is regarded as "full packet size", and any bytes in excess of that number are truncated.)

PCAP log mode:Selects if the captured IP traffic should be logged to either the regular TEMS LogFile stored on the PC or to a PcapFile stored on the device performing measurements. Only available if Client is set to On-device.

PCAP File Path: Specifies the folder on the measuring device where the PCAP file will be stored. Only available when PCAP Log Mode is set to PcapFile.

Minimum Disk Space:Sets the minimum free disk space in bytes. When there is less free space than the specified value, logging to the PCAP file will be stopped. Only available when PCAP Log Mode is set to PcapFile.

Filter: Type of filtering to apply to IP packets.

Optimized Performance: Capture of IP packets is reduced to the minimum needed to compute KPIs. (Packets are filtered with respect to IP address, protocol [TCP/UDP], and port.)

Headers Only: The first 54 bytes of every IP packet are captured. This is frequently the preferable setting.

None: No filtering of IP packets. This means that all packets belonging to any service used by the PC will be captured; packets are filtered with respect to IP address only. By default, when this option is chosen and Client = "PC", IP Protocol Reports are only written to the logfile; they do not appear in the user interface. This is done for performance reasons. You can show IP Protocol Reports by navigating to File > Options > General and turning off the option "Hide IP Protocol Reports...". Note, however, that for throughputs above 25 Mbit/s or thereabouts, this must be avoided since the processing load will overwhelm and crash the application.
The information element "TCP Packet Loss" and the event "IP Interruption Time" require that the Filter parameter not be set to "Optimized Performance".