Orbtalk have a range of SIP trunk products that work TalkSwitch
TalkSwitch is designed for a small business: Each TalkSwitch telephone system comes complete with built-in voicemail, auto attendants to answer calls, music on hold, caller display and an extensive feature set. TalkSwitch is a hybrid PBX that works with standard analogue and IP telephone sets. It works with analogue telephone lines and has the option of VoIP for multibranch networking and select service providers. Every TalkSwitch comes with an easy-to-use configuration program for both local and remote setup. It's a complete owner-friendly™ system for your small business.