UDP Port Unreachable - Massive Traffic

I noticed the network traffic lights between my Sipura SPA-3000 and my Asterisk box were flashing continuously, as well as the network light on the back of the SPA-3000. Obviously a lot of traffic was being generated between the server and the Sipura device.

tcpdump reveals:

11:15:18.943238 IP (tos 0x68, ttl 64, id 2525, offset 0, flags [DF], proto 17, length: 200) > UDP, length 172
11:15:18.944106 IP (tos 0x0, ttl 250, id 26101, offset 0, flags [none], proto 1, length: 56) > icmp 36: udp port 16436 unreachable is the Sipura, is the Asterisk server

This message is being generated every 0.02 seconds which is a continuous flow of messages back and forth between these devices.

The server and the Sipura are connected through a Linksys WRT54G. I never access any of these devices over the internet as this is strictly a local VOIP setup.

Everything is working fine, but the continuous traffic between the server and the Sipura is very disconcerting. Seeing those lights flashing all the time is distracting.

How can I stop this mindless traffic?

is this during a call ? a 20ms audio packet means 50 packets a second.

This network traffic stream of attempts to communicate with UDP port 16436 on the Sipura is constant. That is, it is happening at all times.

The Sipura works fine. I can make and receive calls using the phone connected to it. Everything is working fine, it’s just that there’s this constant RTP network traffic.

Rebooting the Asterisk server made this problem go away. I was only restarting Asterisk during my debugging. Rebooted the server and now everything is working well and no more excessive traffic.