Why 127.0.0.1 can not receive any data,but MulticastAddress can?

Question

Why 127.0.0.1 can not receive any data,but MulticastAddress(224.123.111.101) can? I use jmfstudio to tansport media and set the dest address to 127.0.0.1.I use anther jmfstudio,and fail to receive it.(ps:wo jmfstudio runs in the same machine at the same time).But after I change the dest addrest to 224.123.111.101,it receive data.Can any one tell me why?

Answer 1

The origin code is to transmit stream is(ip 127.0.0.1 ,port 22222)
localAddr = new SessionAddress(InetAddress.getLocalHost(), port);
destAddr = new SessionAddress(ipAddr, port);
As you said,the receiver reports 22222 is used.
But After I change it to
localAddr = new SessionAddress(InetAddress.getLocalHost(), port+10);
destAddr = new SessionAddress(ipAddr, port);
It says waiting for "Waiting for RTP data to arrive..."