• More reliable than other unified communication devices.
• Lower cost of ownership.
• It extends the video capability to your workers during a single, unified communications infrastructure from the desktop to teleprocessing rooms.
• Interoperability and standards support.
• It is scalable for up to 40,000 users.
• It can be extensible to 80,000 users.
Room for Improvement:
• One of the major flaws in the unified CM is handling the configuration of the Voice mail port.
• Failure of higher call-control utilities such as transmit recall.
• Failure of higher directory searching and call on utilities.
I have work on Cisco Unified Communication Manager (Call Manager) for one and a half years and it is a remarkable device which provides fully integrated communications, converging voice, video, and data over a single network infrastructure using standard protocols.