It is a way to protect company’s money by making use of advanced tools. ^_^

######Alternative call: If another call is coming when you are using the phone, just press ‘Alternate’ to change to the other call in circle. This feature support more than two calls at the same time and is limited only by software settings.

######Call forward: When you are away, if you want others still use the same number to find you, use the call forward feature. Press ‘>’ and you have two choice of call forward: fixed and variant. The first is to forward to your message center and the other is to forward to a number you enter.

… (maybe you can help me to add more)