If there is an outage, disruption, or other degradation of the power, network, or telephone services at your location, the voice, instant messaging, presence, and other features of Office Communications Server 2007 R2 and any device connected to Office Communications Server 2007 R2 may not work properly.

Voice communications with Office Communications Server 2007 R2 depend upon the availability of the server software and the proper functioning of the voice clients or the hardware phone devices connecting to the server software.

For those locations where you install a voice client (for example, a PC running Office Communicator 2007 R2 or an Office Communicator Phone Edition device), it is recommended that you maintain a backup option for users to call emergency services (for example, 911, 999, and so on) in case of a power failure, network connectivity degradation, telephone service outage, or other problem that may inhibit operation of Office Communications Server 2007 R2, Office Communicator 2007 R2, or the Phone Edition devices. Such alternative options could include a telephone connected to a standard public switched telephone network (PSTN) line or a cell phone.

Please note that the use of a multi-line telephone system (MLTS) may be subject to U.S. (that is, state and/or federal) and foreign MLTS laws that require the MLTS to provide a callers telephone number, extension, and/or physical location to applicable emergency services when a caller makes a call to emergency services (for example, when dialing an emergency access number such as 911 or 999). Neither Office Communications Server 2007 R2, Office Communicator 2007 R2, nor Office Communicator Phone Edition Devices provide the caller's physical location to emergency services when a caller dials emergency services. Compliance with such MLTS laws is the sole responsibility of the purchaser of Office Communications Server 2007 R2, Office Communicator 2007 R2, and Office Communicator Phone Edition devices.