Special thanks to Eric Phipps and Dave Jodhan, NOC Technicians, for providing the information and diagrams in this blog.
One of our customers had an interesting question that concerns setting up group calls and call forwarding:
Can calls be forwarded to an external line like a cellphone if there are multiple devices registered to the same SIP address?
OnSIP has a unique feature that allows any number of user agents (phones, soft phones, etc.) to be registered to the same SIP address. For example, you can have one phone at your cubicle, one at your home office and also a soft phone to take calls on your laptop, all registered to your extension. When a call is made to that extension, all three devices ring, allowing you to take the call on any of them. In usual cases, if the call is not answered on any device, the call is forwarded to a voicemail box associated with that extension.