I have a problem with RTSP streaming over UDP because of port forwarding.
I think I have found a reason using WireShark, but I need someone to confirm and/or suggest a solution.
1. Internet client sends UDP packet from IP A : 555
2. Packet is received and forwarded from inner router IP B : [random port 777] to local Wowza IP
3. Wowza starts sending video to B : 555
4. Packets are not forwarded to client outer ip A, because forwarding table expects 777 but not 555
Internal NAT table should be based off of source port. UDP packets will be addressed to the destination IP/port; the router records the source IP/port in the address translation table and replaces them with router IP and random port, which is then sent to Internet client. UDP is not stateful, so the scenario you're describing shouldn't matter. It seems you are not allowing new connections through the router.
C>S: (tell server to use client UDP ports)
S>C: (tell client to use server UDP ports starting at 6790 which is the default for Wowza)
S>C: (from server UDP ports to client UDP ports)
C>S: (from client UDP ports to server UDP ports)