Orbtalk have a range of SIP trunk products that work with the Mitel 3300
The Mitel 3300 CXi media gateway replaces traditional PABX or key systems to greatly simpify communications and offers everything needed to support a small office.
The integrated data switch within the CXi enables computer, printer and high-speed internet connectivity to one compact box and over one line.
These gateways are an ideal introductory level IP telephony solution but can support up to 100 IP phone users, which means that you won't have to replace your telephone system when your business grows. The CXI controller also includes PoE (Power over Ethernet) support for IP phones.