This article explains how to install a high-end telephone exchange for free at home or in a company. This is not a step-by-step guide (there are many on the Internet) but rather a guide to understanding the overall system architecture, key options, and installation steps. Those living in Dubai need good telephone systems like what’re provided by Grandstream Distributor Dubai.
A free telephone exchange that allows free phone calls almost everywhere is the miracle of SIP telephony on the Internet.
The first principle is to build the system on the standard SIP which is the standard of the Internet to establish sessions between equipments on the Internet. The second principle is to overcome physical constraints. All equipment will be connected directly to a local IP network connected to the public Internet. The system consists of 4 elements:
The network. It’s the Internet or any network permanently connected to the Internet (ADSL, cable, Wi-Fi)
The RasPBX central office somewhere on the Internet. The easiest way is to install it at home but it can be anywhere on the Internet.
Phone sets that can be on your local network or anywhere on the Internet. A station is either a SIP phone connected directly to the local area network with or without a wire (use the DECT standard and a SIP base), or software on your PC using a headset and a microphone or handset to connect to a USB plug, or an FXS ATA adapter that allows you to reuse existing analog phones or your mobile phone with SI software.
Network lines to connect to either other SIP systems or older analog systems. These trunks are either virtual lines provided by a SIP operator, or an old analog line converted to SIP by an FXO adapter, or a line provided by your box.
This is a very important point to understand. Your network is no longer a physical network, it is a virtual network. A single telephone exchange serves many physical locations. Better, users can “take” their phone with them and be part of this central from any Internet connection. Who can do the most, can the least and at first, you can of course install everything on the same physical local network.