Asterisk voice issue

Question

I am facing issue in asterisk and one of the called party is unable to hear my voice.

The voice problem disappears if I switch off the firewall.

I checked the logs and could see the below error : Dec 23 13:56:04 phone880 kernel: Firewall: *INV_NOSYN* IN= OUT=eth0 SRC=216.245.200.2 DST=74.125.139.125 LEN=494 TOS=0x00 PREC=0x00 TTL=64 ID=13898 DF PROTO=TCP SPT=44005 DPT=5222 WINDOW=564 RES=0x00 ACK PSH URGP=0

I am unable to understand this *INV_NOSYN* , can anyone please help ???

Answer 1

Asterisk usually not use TCP port 5222.

Your output is output of LOG destination in firewall, it can be any and INV_NOSYN here is prefix for logging. For more info you need check your firewall script, no way say which one.

Other option add firewall/iptables tag to this post, maybe firewall expert can say you which firewall script usually put such prefix.

For voice you need permit ports 10000-20000 udp( configurable in rtp.conf file). Also you need check it not NATed or NATed correctly.