One-way audio through Checkpoint Firewall Mediation Server tries to use port 0 RRS feed

  • Question

  • Hi


    I have a OCS environment in a test environment beside our internal network. A checkpoint Firewall is located between the networks. Inside the internal network I have a Dialogic Gateway connected to our PBX. In the OCS Environment I have a Mediation server. If a place a call to a Communicator client everything works alright. If I make a call from a Communicator client I get one-way audio. My audio from the OCS environment can´t pass the firewall. After some troubleshooting and some network sniffing we found out that the Mediation Server tries to use port 0 as destination port for the UDP-session. (I thought It only handled TCP but this is the problem anyway) The firewall did not like this. Quote: 


    "Port 0 is officially a reserved port in TCP/IP networking, meaning that it should not be used for any TCP or UDP network communications.


    However, port 0 sometimes takes on a special meaning in network programming, particularly Unix socket programming. In this environment, port 0 is a programming technique for specifying system-allocated (dynamic) ports.


    Instead of "hard-coding" a particular port number, or writing code that searches for an open port, Unix programmers simply specify port 0 as a connection parameter. That triggers the operating system to automatically search for and return the next available port in the dynamic port number range.


    This programming technique does not work the same way in Microsoft Windows as it does in Unix."


    Is there any way I can configure the Mediation server to NOT use port 0 as destination port ?



    Monday, July 2, 2007 8:19 AM


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