This may be related to the other problems I'm having getting webrtc2sip to work on my test system. Occasionally (every 3 or 4 connections perhaps, I haven't managed to identify the exact circumstances it happens in yet) I get thousands of lines like the following appearing very quickly in the webrtc2sip debug:
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
*[DOUBANGO INFO]: Sending DNS query to "192.168.1.250"
then:
*[DOUBANGO INFO]: CloseSocket(13)
*[DOUBANGO INFO]: CloseSocket(14)
***[DOUBANGO ERROR]: function: "tnet_dns_resolve()"
file: "src/dns/tnet_dns.c"
line: "475"
MSG: Failed to contact the DNS server.
192.168.1.250 is the correct DNS server on our internal network.