Several important considerations can impact your determination of whether Enterprise Voice is appropriate for your organization.
Power, Network, or Telephone Service Outages
If there is an outage, disruption, or other degradation of the power, network, or telephone services at your location, the voice, instant messaging (IM), presence, and other features of Office Communications Server and any device connected to Office Communications Server may not work properly.
Enterprise Voice Depends on Server Availability and Voice Client and Hardware Operability
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.
Alternative Means of Accessing Emergency Services
For those locations where you install a voice client (for example, a PC running Office Communicator 2007 or an Office Communicator 2007 R2 Phone Edition device), it is recommended that you maintain a backup option for users to call emergency services (for example, 911 or 999) 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 Communicator Phone Edition devices. Such alternative options could include a cell phone or a telephone connected to a standard PSTN line.
Emergency Calls and Multi-Line Telephone Systems
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 caller’s 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.