Internet Engineering Task Force's (IETF's) Session Initiation Protocol (SIP), Nortel's MCS 5100, and Cisco Systems' Cisco IP Phone 7970 are highlighted as experts comment on the advantages of voice data applications, which, when they run on VoIP systems offer significant payback for putting voice on an enterprise network. For instance, says Kevin Johnson of Mitel, since VoIP has matured and the early stages of mere delivery of IP telephony are in the past, the industry will actually see the promise of applications surrounding VoIP. Enterprise collaboration is the most likely market, since it supports the ability of voice and data applications to combine IM, presence, Web, and videoconferencing. Voice is also getting into corporate applications, and IP abilities are changing the phone on the desktop. Alex Hadden-Boyd, director of IP communications and marketing for Cisco, says the cost of linking conventional telephony systems with corporate data and applications is simpler and less expensive with voice running over the IP LAN, and functions can be provided by different systems or services. SIP is oriented toward PCs, PC-type devices, and the Internet, and vendors have used it to merge presence, IM, voice, Web and video conferencing into real-time communications applications connected to an IP PBX. Siemens layers OpenScape atop Microsoft Live Communications Server and Windows 2003, and OpenScale also works with another vendors equipment, including Cisco's. MCS 5100 is highlighted as an excellent, described example of what VoIP that is combined with IM and presence can do.