50.1.4 Buffering in Connection with Logfile Recording

For each connected device, TEMS Investigation continuously maintains an internal buffer with the latest signaling. When starting a logfile recording (by any of the available methods), you decide how much of this buffered content should be inserted at the start of the logfile. There are pros and cons to including the buffered data, as discussed below.
You may want to use a large buffer:

If you wish to capture as much as possible of the context surrounding a device activity, for example, the signaling leading up to the establishment of the call or data session.

If, at the start of a new recording, you want to evaluate some condition that depends on previously obtained data. For this to work, you need to have the relevant data available in the buffer so that it is copied into the new logfile.

You may want to use a small buffer or no buffer at all:

If you have no particular interest in what happened before the recording started, or if you want to prevent any possible confusion that might result from unexpected and unrelated data appearing at the start of the logfile.

If you want to avoid duplication of data, for example in order to prevent skewing of statistics. Consider a script where voice calls are repeated in a while loop and a new logfile is recorded in each turn. If the Start Recording and Stop Recording activities are put first and last in the loop, then any two consecutive logfiles will overlap. Now if a call fails (e.g. is dropped), the failure will likely be registered in both logfiles, and this duplication will distort any statistics that are computed based on the data. To prevent logfiles from overlapping, decrease the buffer size (possibly to zero). Another way to avoid logfile overlap is to insert Wait activities in your script; see section "Notes on Script-controlled Logfile Recording".