I use phone.systems, mostly with SIP lines and couple of DIDs. One of the SIP lines always gives a busy tone and doesn’t ring, no matter if I’m calling from a second extension or to a DID number.
It’s hard to predict exactly what SIP device you’re using, but in general you can try the following:
- Restart the device;
- Check the SIP account status, whether it is online (green) in the phone.systems™ GUI;
- Check if the SIP account credentials entered on the device are the same as in the phone.systems™ GUI;
- Check the logs in phone.systems™. Log records may show a response code and other details that may help understand why it doesn’t work;
- Make sure that multiple devices are not connected to one SIP account; usually only one device can be connected to the same SIP account;
- Check the firewall / NAT settings of Internet access, restart the Internet access point (router, etc.) or try a completely different Internet access point;
- If that doesn’t help, please contact technical support for further assistance.