why does SQL Server Profiler measure "round-trip" time for the duration column?

Why does SQL Server Profiler measure "round-trip" time instead of just running time for the duration column? 开发者_StackOverflow中文版If I see a long running query in the profiler output, the cause could be the database server itself, the application/web server, or even the clients, plus all the network paths between them. That measure is not helpful at all, because when I am looking at the profiler output, I just want to know whether SQL Server itself is the bottleneck.

By the way, PostgreSQL's log_min_duration_statement does measure just the running time.