I implemented the two-way transmission system of sound

and video captured streams by using JMF.It is possible

for the host with local address(and possiblly its

address is translated to the global one by NAT) to

transmit streams to the host having global IP address

on the Internet. However it is not possible vice versa

i.e. it is not possible for the host having a global IP

address within a LAN to transmit to the one having a

local address within an ISP.Please see JMF Example .