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.
From mobiSIP Android or iPhone: SIP Client iPhone is uniquely designed and developed to add the power of making voice over internet transfer protocol calls directly through the Android or iPhone. It’s developed by mobisnow.