tive office suites in managed office buildings that rent out furnished office space. Additionally, organiza- tions with a large network of telepresence systems can hire outside firms to manage the systems for them. Manufacturers of telepresence systems include Polycom, Inc., Tandberg (part of Cisco Systems), and Vidyo, Inc. Using Hosted-IP PBX Services As its name suggests, hosted-IP PBX services relieve an organization of the burden of maintaining the hardware and software for a phone system and Unified Communica- tions (UC) and moves it all instead to either a carrier's or provider's site. This solution is more attractive to small and midsize organizations that do not want to commit to purchasing and maintaining VoIP hardware. Some hosted IP providers also provide e-mail and Internet access. Customers that use a hosted IP PBX service are connected to their system via high- speed network connections. These network connections also transmit busy signals and Value-Added Applications for Telephone Systems ring tones between the provider and the customer's handsets. The connection also sup- ports Internet access and e-mail traffic. Depending on their provider, IP telephones are either installed by the provider's technicians or shipped to customers. Remote employees access the service from their PC or mobile handset. In addition, users have PC-based graphical web interfaces for UC and other features, including the following: Audio conferencing activated from the PC Integrated mailboxes on PCs with access to voicemail, e-mail, and fax messages Instant messaging with graphical indications of users' availability Collaboration for working jointly with employees on shared documents Contact center software Offsite call forwarding to mobile devices As with onsite telephone systems, voice security and protection from hackers depend on LAN capabilities. These capabilities include data-grade cabling, switches, and routers capable of prioritizing voice and proper security precautions. Hosted VoIP systems are attractive to small