The SoundPoint IP 501 is a three-line Voice over IP telephone that seamlessly integrates with IP PBX and Softswitch vendors' IP solutions. As protocols develop and standards evolve, it's easy to update the phone in the field via a software download, thus enabling new features and functionality for the phone and protecting your investment. Whether you deploy MGCP or SIP standards, Polycom offers a solution that fits all your business communication needs.