Problems establishing Voice Calls

Hello,

i’ve installed Openfire and Spark in the newest avalible Versions.

Also i opend the ports 10000 till 20000 in the firewall for tcp and udp and some xmpp client ports.

After this i enabled the media gateway service.

Now i’m receiving the following exceptions on the servers console when trying to establish a call from one client behind a nat firewall to another

Does anybody have a clue?

Exception in thread “Thread-27” java.lang.NullPointerException
at org.jivesoftware.openfire.mediaproxy.Channel.run(Channel.java:124)
at java.lang.Thread.run(Unknown Source)
Exception in thread “Thread-28” java.lang.NullPointerException
at org.jivesoftware.openfire.mediaproxy.Channel.run(Channel.java:124)
at java.lang.Thread.run(Unknown Source)
Exception in thread “Thread-29” java.lang.NullPointerException
at org.jivesoftware.openfire.mediaproxy.Channel.run(Channel.java:124)
at java.lang.Thread.run(Unknown Source)
Exception in thread “Thread-30” java.lang.NullPointerException
at org.jivesoftware.openfire.mediaproxy.Channel.run(Channel.java:124)
at java.lang.Thread.run(Unknown Source)
Exception in thread “Thread-34” java.lang.NullPointerException
at org.jivesoftware.openfire.mediaproxy.Channel.run(Channel.java:124)
at java.lang.Thread.run(Unknown Source)
Exception in thread “Thread-35” java.lang.NullPointerException
at org.jivesoftware.openfire.mediaproxy.Channel.run(Channel.java:124)
at java.lang.Thread.run(Unknown Source)
Exception in thread “Thread-36” java.lang.NullPointerException
at org.jivesoftware.openfire.mediaproxy.Channel.run(Channel.java:124)
at java.lang.Thread.run(Unknown Source)
Exception in thread “Thread-37” java.lang.NullPointerException
at org.jivesoftware.openfire.mediaproxy.Channel.run(Channel.java:124)
at java.lang.Thread.run(Unknown Source)