Recently while working with SJphone on Windows 7 workstation I didn’t encounter any issue but when doing the same job on a laptop I got this little puzzling error message:
No active network interface
And still I had connectivity. Sniffing around with Wireshark showed that the SIP register paket did not contain the registrant IP which must be passed to the VoIP server.
A working workaround I came quickly to test was to deactivate every not needed NIC under Windows 7, basically you deactivate every card except for the Ethernet/LAN. Very funny. At least I would like to be able to select which interface I want to use.