The two XxxxxClient classes produced by Microsoft (TcpClient, and IrDAClient in the NETCF) have various documented behaviours and various actual behaviours for close/dispose/finalize on the various platforms. :-( The current TcpClient implementation is that Close/Dispose closes the connection by closing the underlying socket and/or NetworkStream, and finalization doesn't close either. This is the behaviour we use for the here (for BluetoothClient, IrDAClient). (The documentation in MSDN for TcpClient is still wrong by-the-way, see Microsoft feedback #158480).