Applications Layer

There are effectively a limitless number of applications that can be part of a Unified Communications system, because third-party applications can be developed to closely integrate with the Cisco suite of products. The following is a list of the more common applications found in a Unified Communications system:

• Voice Mail: Voice mail can be provided using Cisco Unity, Unity Connection, or Unity Express. Unity and Unity Connection run on the MCS 7800 series platforms, and Unity Express is a self-contained module that is added to an ISR router and administered through the command line and GUI. The maximum mailboxes and recording time capacities vary depending on which module (either Advanced Integration Module or Network Module) is installed in the router.

• Cisco Emergency Responder: This application tracks the location of an IP telephony device based on the physical switch port it is connected to. This information is attached to the caller information in the event the device calls 911, which in turn allows 911 responders to locate the device (and therefore presumably the emergency) more precisely. 911 operation in a Unified Communications environment is a major design challenge because a VoIP phone system can easily throw out the premise that a PSTN call is placed from the same location as the phone that made it.
  

• Cisco Unified Contact Center [Express]: This is a call center application with full feature support for advanced call distribution, supervision, escalation and logging. Versions are available to support small and large call centers.

• Cisco Unified Meeting Place [Express]: This is a full-featured web-conferencing application enabling voice and video conferencing as well as document sharing and collaboration, whiteboarding, and conference participant management.

• Cisco Unified Presence: This extends the native capabilities of Unified CM 6.x+ to indicate presence information. The native capability includes on/off hook status in speed dials and call lists, whereas the full applications server provides detailed presence information as typically found in chat applications ("On the Phone," "Out to Lunch," "Do Not Disturb," and so on).

Endpoints Layer

An increasing variety of Cisco Unified IP Phones (and third-party IP phones) can be part of a Unified Communications deployment. All Cisco Unified IP Phones provide a display-based user interface, user customization, Power over Ethernet capability (where appropriate), and support for G.711 and G.729 codecs (and, on some models, Cisco Wideband and/or iLBC codecs).