UDP
5060,5070,8000,8002,8004,8006,8020

# SIP (TCP) 
voip_tcp = "5060" 
# SIP, IAX2, IAX, RTP, MGCP (UDP) 
voip_udp = "{5060, 4569, 5036, 9999 >< 20001, 2727}"

# SIP on UDP port 5060. Other SIP servers may need TCP port 5060 as well 
iptables -A INPUT -p udp -m udp --dport 5004:5082 -j ACCEPT 
# IAX2- the IAX protocol 
iptables -A INPUT -p udp -m udp --dport 4569 -j ACCEPT 
# IAX - most have switched to IAX v2, or ought to 
iptables -A INPUT -p udp -m udp --dport 5036 -j ACCEPT 
# RTP - the media stream 
iptables -A INPUT -p udp -m udp --dport 10000:20000 -j ACCEPT 
# MGCP - if you use media gateway control protocol in your configuration 
iptables -A INPUT -p udp -m udp --dport 2727 -j ACCEPT