Extension Overview
An extension is a short internal number. Extensions allow users to make and receive calls. You can assign extensions to every employee in your organization.
Extension types
SIP Extension
A SIP extension is based on SIP protocol.
To use a SIP extension, you need to enter the extension credentials on an IP phone or a softphone. After the extension is registered on a phone, you can make and receive calls.
Extension format
Yeastar Cloud PBX supports 1-digit to 7-digit extension format. The default extension format is 4-digit number.
Before you create extensions, you can go to
to change the extension format and range.