Can't limit the video stream output

[triplebit]

I use the following advanced string settings in order to stream to a remote PC.
:sout=#transcode{vcodec=mp4v,vb=16,scale=1}:duplicate{dst=display,dst=std{access=http,mux=asf,dst=10.0.0.11:8081}}

Though I set vb to 16, I see in the remote PC statistics info that it consumes 1400 kb/s if it located on the same LAN. If on the Internet, than it receives some 150 kb/s , the maximum baud rate.
What am I doing wrong since I want to limit the baud rate bellow some maximum?

Regards
Ramzi