[Asterisk-Users] Problems connecting to and from my Asterisk server :(

[Leo Burd]

Hello there,

I'm a new Asterisk user and I'm having difficulties to connect to and 
from my Asterisk server.  Can anybody give me a hand?

Here's some background information:
* I'm running RedHat Linux Enterprise 4.0
* When iptables is stopped, my server can register with IAX service 
providers and receive registrations from IAX softphones.  However, it 
does not succeed in registering with SIP servers and does not even 
receive messages of SIP clients trying to register.
* When iptables is running, nothing can register with my server.  Not 
even an IAX softphone such as DIAX.  The only way to reach my Asterix 
server is through IAX peers with whom the server has registered itself.

Does anybody have a suggestion or concrete examples of how to proceed?  
I've been struggling with this issue for too many days and I don't know 
what to do...

Thanks in advance,

Leo