UDP : Two way transfers to server application <-> client applet ?

Networking & Multiplayer
#1

Why my client applet from server wont open a two way transfer ?

my udp transfers from my client applet to my server, they travel allways right, but my transfers from my server to applet never success,
my home firewall allways blocks my packets, why so, why there is no two way transfer enabled, i am using applet ?


public void UDP_send () throws Throwable
{
	byte [] buf = new byte [ 4096 ];
	buf = "test packet 001".getBytes();		
	UDPsend.send ( new DatagramPacket ( buf , buf.length , received_from_applet_datagrampacket.inetaddress , 32323 ) ) ;
		
}

thats my test send code, from my server, this packet blocks to my home firewall, i dont know why.

do i need to have udp connect() from applet to server to make two way transfers between client applet and the server application ?

#2

Try using the port indicated by the packet you received (i.e. not 32323). If the client is behind a NAT router there is a possibility that their private internal socket address port is mapped to a different external port on the router (perhaps there is another client on the network that has already claimed that port mapping, or it’s simply a bad router).