When you receive an incoming call to your phone number, your other telephones (cell, home phone, car phone) will ring as well and the first one answered will be connected to the caller. Basically the call will be routed to all phone sets, which you will list in simultaneous ring option.
The Center of the System Administration was founded in 2001, in order to satisfy the needs for IT services of small-to-medium scale organizations by providing Open Source Software solutions.