Strange situation. Have 2 offices each with phones connected to the Freeswitch server in Office 1.. Office 1 Freeswitch Server PFsense Internet Office 2 Telephone 2 Telephone 1 à 192.168.0.15 à 192.162.0.1 à 156.233.20.37 ß Telco Router ß 192.168.1.123 192.168.0.10 152.43.37.129 If the telephone in Office 2, call the telephone in office 1 everything works perfectly. If Office 1 telephone, calls Office 2 Telephone, Telephone 2 rings they can pick up while Freeswitch still gives to Telephone 1 a ring tone even after they pick up and eventually send telephone 1 to voicemail. I placed wireshark on the Freeswitch Server (Ubuntu 10.4 ) and I see the following: Call Originates from 192.168.0.10 to 192.168.0.15 with a SIP packet to 152.43.37.129 I can see that the Call RTP/UDP is to be port 25542 received from Telephone 2 I see that Freeswitch sends a packet to 192.168.0.10 (Telephone 1) I see that Telephone 2 at 152.43.37.129 is asking to talk on port 25542 And then I see that the Freeswitch server send an ICMP packet to 152.43.37.129 stating that the port 25542 is unreachable. Obviously they are talking, just not communicating! The PFsense firewall has all ports open and UDP enable. I even placed a rule that all traffic from 152.43.37.129 be forwarded to the Freeswitch server, and still no voice can be heard. What I dont get, is where does the problem exist, since Office 2 can call us and everything works. This suggest that there is no firewall issue SIP and RTP/UDP is working. Yet when we call, we see that the port has been negotiated which means the SIP port is working and then we get the error that the port is unreachable. My question: - Is the problem in the Ubuntu server ( no firewall) or is it elsewhere? They seem to get in without a problem, why cant we get out? Just to clarify Telephone 1 can make any calls to any other Telephone number (local and long distance) and everything works perfectly. Is the problem in the Telco router? Unable to put a tracer on the Telco router but inside Office 2 wireshark states that it is not receiving anything from Office 1 which corroborates what we see in the Freeswitch server wireshark trace. When I place a wireshark trace at the PFsense server I see the exact same thing as what I see on the Freeswitch server wireshark trace. I can see the Port is unreachable error go to the Office 2 telephone and in Office 2 I see receiving the ICMP message that the port is unreachable. My second question: - Why would the port be unreachable and is it on the Ubuntu server? PFsense server? or Telco router? Third question: - Is there a place in Freeswitch I can check to verify that the RTP ports are in the appropriate range? Any suggestion on how to troubleshoot or resolve this issue would be greatly appreciated. CJB