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.
Callforeign is a global provider of customized end-to-end VoIP Solutions & Services for Internet Telephony Service Providers (ITSPs) offering wholesale & retail VoIP services to their customers.