General Information on Real Audio

Use this function to change/show parameters used by the RealAudio proxy application.

RealAudio protocol is a special protocol developed by Progressive Networks, which supports live and on-demand audio from the Internet. In the recommended configuration, the protocol requires two connections. The first connection is a TCP connection from the RealAudio player to the RealAudio server.

After this connection is established, the RealAudio server optionally establishes a UDP channel back to the player. If the RealAudio server is TCP only, no further action is required by the Firewall. In the scenario where UDP is used, the UDP connection is dynamic in the sense that the destination port number is dynamic. The Firewall supports the RealAudio protocol by monitoring and identifying these RealAudio TCP connections.

Once a connection is identified, a dynamic filter rule for a UDP packet will be defined. This filter rule will be removed once the RealAudio TCP connection is closed. This is transparent to the RealAudio user. No extra configuration or knowledge is needed. Enabling RealAudio connections through the Firewall simply requires providing a filter rule for the RealAudio TCP connection.

Be aware that if you configure the Firewall to support RealAudio, a deny filter rule, which normally would stop the UDP packet is dynamically changed, just for the required packet, to a permit filter rule. If that filter rule specified log=yes, you will see the actual permit in the log.

Further Information

Supporting the RealAudio Protocol

Server Port Number

TCP port number used to establish RealAudio connections. The default is 7070, however, you can reconfigure it to any valid TCP port number.

Maximum Concurrent Sessions

Fill in the maximum number of simultaneous sessions allowed for RealAudio. The default is 10. It can be any non-negative integer.

OK

Press the "OK" button to save changes and close the window.

Cancel

Press the "Cancel" button to close the window without saving any changes.