[asterisk-users] Calling multiple phones at ones

[Ivan Demkovitch]

Hello group!

I’m new to Asterisk but got one running finally :)

Now I’m trying to solve following problem. I have company Automated Attendant and each employee have
SIP phone at home, SIP phone in office, cell phone.

I want all those 3 phones to be “one”. So, if someone calls our company number and dials my extension - I’d like 3 phones to ring at the same time.

What is this feature and where should I look for samples, etc? I’m going by “Asterisk: The definite guide” book and pretty confident with those concepts described but not sure 
how to achieve what I described above. 

Thank you,
Ivan