Illustration:

◆Register: Through the internet, the Web Phones of New York, Germany, Sydney are all register on the Qmaster IPPBX located in New York and get the extension number, the FXO gateways of New York, Sydney, Germany register on the Qmaster IP-PBX after connecting with the local PSTN number and get the extension number as well, Qmaster IPPBX register on the SIP system of upper-level VOIP operator and get the VOIP number. 

◆Intranet free communication: Web Phones in New York headquarters, subsidiary company in Germany and Sydney and the FXO gateways under the management of the IPPBX in New York headquarter can make the extension communication free between the branch organizations.      

◆Call from outside: Other network telephones or the web phones belong to the VOIP operator can dial New York headquarter IP-PBX via VOIP operator (The inner net number divided to the IP-PBX by the VOIP operator). After hearing the voice of “hello, this is ⅹⅹcompany, please dial the extension number”, please dial the extension Web Phone affiliated to IPPBX of Sydney, Germany and New York the second time. The local general telephone user of Sydney, Germany, New York.(PSTN in the picture) dial the local number (Through the FXO gateway of the companies in different places t connect into the local PSTN) can connect with the IP-PBX in New York directly through the internet then go into the headquarter ‘s IP-PBX in New York. After hearing the voice of “hello, this is ⅹⅹcompany, please dial the extension number” then for the second time to dial the each extension web phone affiliated to the IPPBX of Germany, New York.

◆Intranet call out: All the extensions the IP-PBX belong to can through the upper-- level operator of the IP-PBX to dial the common telephone all around. The extensions in New York and Germany can dial the FXO gateway of their own company to get through the local call line and dial the local call. Each extensions within the three regions can through the internet to dial the FXO gateway in Germany, New York or Sydney first , when get through, can dial to the local call thus to eliminating the long distance route, make the long distance become the local call.