Orbtalk have a range of SIP trunk products that work with the AYC IPBX
The IPcts is an IP Telephony telephone system for the Small Business Market (SMB). It is a “stand-alone” product that is rack, desktop, or wall mounted. Unlike other claimed systems that are software loaded on a PC/Server, it is a true IP PBX Telephony System and not an IP Enabled system that requires additional plug in cards for VoIP or Voicemail. Also, as a true IP Telephony system, it requires only 1 cable to the desk, not 2 separate cables like other systems.
This system is a Converged Telephony System that is aimed at the SMB market for companies having up to 25 extensions and a limited budget. It is by far the best value for the price and accompanying support.