The Keyed option instructs the Server to scan the Log twice. First, it scans the Log (within the specified Time Interval) and finds all records matching the filter string. These strings are not displayed, but their Prefix Keys are remembered. The Prefix Key is the first part of the record (not including the time stamp and the level marker) till the first space symbol. Up to 100 different Prefix Keys are remembered.
Then the Log is scanned again (within the specified Time Interval), and the Server displays all records that have Prefix Keys matching one of the remembered Prefix Keys.
Some protocols (such as SIP) do not use connections. A SIP session ("dialog") consists of several packets (each packet is recorded with its own SIPDATA-NNNNNN Prefix Key), but all packets contain the same Call-ID line. Use the
filter string with the Keyed option to display all SIP session packets: