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<p class="">Hi Anthony,</p><p class="">Thank you very much for your response.</p><p class="">After almost 9 hours of debugging I was able to reproduce the issue.</p><p class="">I went through all our logs and found out whenever a particular customer calls out, we loose connectivity with our router.</p><p class="">I found out the customer had moved his IP Phone from his office to another location. That location has same private IP address as our servers.</p><p class="">On all our servers we use <a href="http://10.0.0.0/24">10.0.0.0/24</a> on eth0 and eth1 has public IP address.</p><p class="">What I did next was isolated a FreeSWITCH server and spawn up a dedicated Kamailio to only send traffic to this FS server. I also changed my lab's LAN from <a href="http://172.16.16.0/24">172.16.16.0/24</a> to <a href="http://10.0.0.0/24">10.0.0.0/24</a>.</p><p class="">Here is what happens when I make a call:</p><p class="">First call is fine and I get:</p><p class="">switch_rtp.c:5846 Auto Changing port from <a href="http://10.0.0.179:61856">10.0.0.179:61856</a> to <a href="http://108.178.144.243:10249">108.178.144.243:10249</a></p><p class="">On second call, here is what happens:</p><p class="">The value of rtp_session->flags[SWITCH_RTP_FLAG_AUTOADJ] is correctly set to 1 but the “bytes" variable is always at zero for following if statement on line 5833 in switch_rtp.c:</p><p class="">if (bytes && rtp_session->flags[SWITCH_RTP_FLAG_AUTOADJ] && switch_sockaddr_get_port(rtp_session->from_addr)) </p><p class="">I also did raw packet captures on eth1, I found out right after my FS receives SIP 183 with SDP from carrier, it sends out following:</p><p class="">1) an ICMP to my public IP address which is 108.178.144.243</p><p class="">2) an ARP broadcast “Who has 10.0.0.179? Tell 208.65.xxx.xxx” (208.65.xxx.xxx is the public IP of the FS server)</p><p class="">Right after that, the router is no longer reachable and 10.0.0.179 will show up in arp table of FS with mac address of the router.</p><p class="">I tested above scenario zillion times to make sure it’s reproducible before reporting back.</p><p class="">What I did next was installing rtpproxy and made few changes to our Kamailio to rewrite SDP and pass the traffic through rtpproxy and when I make calls with rtpproxy in the middle, the problem does not occur.</p><p class="">Any thoughts?</p><p class="">Thank you,</p><p class="">Moe</p></div>