What is asterisk \ how does it work?

i’m new here and recently have been searching about asterisk , after a small search about voip and pbxes.

i have recently met this solution to an ip centrex.
first of all just to confirm could asterisk supply and be an answer to the needs of a 2 line ip centrex will all pbx functions (accept from the voip line which i understand should be supplied by our local carrier?)

i ahve several wuestions about asterisk and the way i works

first of all i understand the asterisk is a sort of a software that should be installed on a server which will be a part of the network while all phones should be connectedto the server is that currect?

i also know that asterisk should supply all functions of a pbx system is thath correct?

moreover, i would like to ask how do you manage all the functions? is i through a web service?

what are the diffrences between the free asterisk to the business?

how do i config each phone that is connected to the server.
could a pc in the network be the server in the system or should there be a new server for this kind of a system ?

thank you , i hope i didn’t bother any of you and really need some answer lol

i heard that there is a service in which you can log with you mobile phone using a wifi to the operator and make phone calls at the cost of a regular phone conversation. does anyone know how does this option called and if it’s possible with asterisk ?

moreover, i heard about a service the lets you have another phone number in a diffrent city. for example if i’m using an operator or a phone in city a and have a city a phone number this service also lets you have a city b number by that you could call to city b phones with the cost of a a city b to city b phone call and not a high cost of city a to city b phone call … does anyone know how does this service called and if it’s working with asterisk ?


If you have GSM with SIP software phone installed on it - you can assign even foreign country number and get calls everywhere where you have WiFi internet.
Same could be done with devices like Grandstream.
And - yes such service you can offer with Asterisk.

thank you for your answer.

however i do not know what sip means. does sip means the provider of the ip telephony netowkr like isp is for the internet?

the sip is a protocol for ip telephony like tcp\ip for the internet?

the sip is a protocol in which the conversation’s data is transffered on?