Quote Originally Posted by sr98user View Post
If you are getting 3 per minute, its probably the keep alive packets from the ATA to the SIP server to keep the UDP NAT entries alive. I am not sure why your router is blocking that traffic. Does it give any reason at all? What router do you have?

Depending on the NAT entry timeout for the UDP packets, you could increase the keep alive interval. To do that, you would need to the timeout or should be able to configure it.
I am seeing my router's log (Cradlepoint MBR900) filled with rejected incoming packets from VoIPo's SIP servers. Also, my ATA's ALG function is trying to send SIP packets out but the router log says it did not forward, apparently because the Grandstream's SIP packet is not formatted properly according to the Cradlepoint.