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.
Provide wholesale international callback service in China for voip service providers and call shops. We offer competitive price and billing system to our wholeseller. We are using SS7 PSTN line and no connection fee to customers.