MiaRec uses unobtrusive packet sniffing technology to record voip calls.
It leverages a port mirroring function, which is supported in nearly all enterprise class switches.
See below example as an illustration of how MiaRec records a call.
When a network packet comes in to the switch, the latter sends out this packet from two ports. One of these two ports is MiaRec server.
MiaRec decodes these packets and saves audio and related call information (source and destination phone numbers) on local disk.