Configurations
of GSM/VoIP networks allow the service providers to avoid the local Wired
Public Switched Network (PSTN) in communication with a GMS mobile handset. As a
result, the high rates charged by telephone companies are avoided.
Siemens Enterprise OpenStage 40 SIP IP-phone is a great solution for people working in the permanent place. This model features a large display and easy setup of various protocols such as TDM, HFA and SIP.