#### SIP on UDP port 5060. Other SIP servers may need TCP port 5060 as well
-A RH-Firewall-1-INPUT -p udp -m udp --dport 5060 -j ACCEPT
#### IAX2- the IAX protocol
-A RH-Firewall-1-INPUT -p udp -m udp --dport 4569 -j ACCEPT
#### IAX - most have switched to IAX v2, or ought to
-A RH-Firewall-1-INPUT -p udp -m udp --dport 5036 -j ACCEPT
#### RTP - the media stream
-A RH-Firewall-1-INPUT -p udp -m udp --dport 10000:20000 -j ACCEPT
#### MGCP - if you use media gateway control protocol in your configuration
-A RH-Firewall-1-INPUT -p udp -m udp --dport 2727 -j ACCEPT