Problems with relaying packets

Hi,
I want to write a rtp-server that distributes incoming data packets to all
connected clients I have problems with sending back packets. I used
rtplisten as sample and added a thread, that is getting received packets and
sends them to the internal recipients list. How to add recipients to
recipient list upon connection. In rtpsend the list is filled with
addDestination(ia, port). If i try to fill the list with
addDestinationToList() in one of the on...() funktions of rtpsession it
doesn't work 

On the client machine i have a rtplisten, but nothing arrives.

Can anyone help me please?

With best regards

Martin Mainka