Background: We have a i2004 that connects to our vpn through a 4 port linux router. We are running a BCM v 3.6 build 2.2c.
Problem :Hey everyone, Im having a issue where my ip phone is periodically not recieving a dialtone/voice on either side of the phone connection. The ip phone does register and can make outgoing calls but will sometimes have no voice or dialtone.
link to schematic:My diagnosis and things ive tried: At first i thought that the problem was with the firewall on the linux router. so i started by adding adding the following lines inside of my firewall.user file to direct the vpn traffic:
iptables -A forwarding_rule -o ppp0 -j ACCEPT iptables -A forwarding_rule -i ppp0 -j ACCEPT iptables -t nat -A postrouting_rule -o ppp0 -j MASQUERADE
Then i read that the registration of the ip phone is done through port udp 7000. so i added the appropriate line inside of my firewall.user and tried again. success the phone registered but i had no voice traffic. I then added a line to direct port traffic 51000:51255 (Im sorry im not posting the iptable commands for this as i am not verry good with the whole structure of linux iptables and chains.) . After doing this i recieved dialtone initially but after about 10 minutes or so i checked again and the dialtone and voice was gone. So then i tried to make a outgoing call and a incomming call and both worked, but still no voice.
Now im stumped, i feel like ive tried soo much to get this to work and now need the help of someone more experienced to either help with my iptables or to give me some insight on what im doing wrong. THANK YOU EVERYONE WHO HELPS IVE BEEN STRESSING OVER THIS FOR A WHILE. THANKS!