Recording a profiling session
Before you can use the network profiler, you must record some data for it to analyze. To do this, you need to use a version of the engine with stat tracking enabled - usually this means either a debug build, or for non-debug configurations, an editor build (specifically, the engine should have been compiled with the STATS macro defined to a nonzero value).
You can pass the "networkprofiler=true" command-line argument to record as soon as the engine starts up, but you can also use the following console commands at runtime to control the recording of network profiler data:
netprofile: toggles recording on and off
netprofile enable: start recording if not already recording
netprofile disable: stop recording if currently recording
The data file will be saved to
<project directory>/Saved/Profiling/<project name>-<timestamp>.nprof. If you see a file named NetworkProfiling.tmp in the same folder, this is just the temporary file the engine uses while collecting data. When the current profiling session is stopped, this file will be renamed according to the scheme above and is then ready to be opened in the standalone tool.