Have you been confirmed whether SIP UDP Ports are not blocked by ISP? This is very common. Try to use some other UDP port which probably should not be blocked by ISP.
Best Regards, Vivek Batra -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Swaminathan S Sent: Wednesday, October 28, 2009 9:34 AM To: sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] Query on inter-domain SIP calls Hi All, I have a (basic?) query regarding inter-domain SIP calls. SIP softphone1 (Xlite) is running on a machine connected to the internet via ISP1 (Internet Service Provider 1). The proxy of this softphone 1 is running on a machine which has a fixed IP a.b.c.d (provided by ISP1). SIP softphone2 (Xlite) is running on a machine connected to the internet via ISP2 (Internet Service Provider 2). The proxy of this softphone 2 is running on a machine which has a dynamic IP w.x.yz (provided by ISP2). We are able to ping IP a.b.c.d from IP w.x.y.z and vice versa successfully. However, the tracert command doesn't seem to succeed. Problem: We are unable to make SIP calls from softphone1 to softphone 2 (or vice versa). We see (using wireshark trace) that the SIP INVITE is sent out successfully from proxy of softphone 1, but it never reaches proxy of softphone 2. We are able to make SIP calls successfully between 2 softphones having the same proxy (i.e., within the same ISP). We are able to make SIP calls successfully between softphone 1 and softphone 2, if the entire connection between softphones 1 and 2 (& proxies) are configured as a VPN. Now our query is, what can be done to be able to make calls successfully, without having to use a VPN? Is the problem that we are facing due to some kind of firewall for UDP packets between ISP1 and ISP2? Regards, Swami. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors Email Scanned for Virus & Dangerous Content by : www.CleanMailGateway.com _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
