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Cisco UCM: Unified communications product overview

The Cisco UC Manager supports instant messaging, video conferencing, mobility and presence technology. The platform can support up to 100,000 users in a cluster configuration.

Editor's note: This article is part of a buying guide on unified communications. The features in this series describe the evolution of UC and its use cases, as well as the important criteria to consider when buying a UC service. The series also compares the top UC products in the marketplace. This article gives a brief overview of Cisco UC products.

The Cisco Unified Communications Manager (UCM) is the vendor's flagship call-control platform geared toward medium to large enterprises that are looking for a complete unified communications (UC) package.

Cisco UCM provides basic functionality such as call control, call routing, IP phone registration, session management, voice, messaging and much more. With its modular design, customers can select the features they need to power their communications, along with a wide array of add-ons.

The latest versions of Cisco UCM run under a customized Red Hat Linux-based operating system that guarantees stability and can support more than 100,000 users in a cluster configuration.

Customers can extend the Cisco UCM offering by installing a number of additional UC services. The most popular UC services found in most deployments are Cisco Unity Connection, messaging and voicemail; Cisco IM and Presence Service, real-time user status and instant messaging; Cisco Expressway, mobility clients and video conferencing; and Cisco WebEx, desktop sharing, presentations and conference calls.

Unity Connection enables messaging, voicemail

Cisco Unity Connection enhances Cisco UCM by enabling a robust Unified messaging and voicemail service in the enterprise. When an incoming caller leaves a message, Unity Connection stores and forwards it to the correct mailbox. Messages can be delivered to a local or remote mail server, such as Microsoft Exchange Online. 

Unity Connection can be deployed on a dedicated server that meets the minimum specifications -- depending on the product version -- or as a virtual server under a VMware environment. Unity Connection provides support for up to 20,000 users per server and up to 250 ports. High availability is supported via clustered servers that tightly integrate with Active Directory, making it an ideal solution for large enterprises that need redundancy.

In terms of security, Unity Connection supports secure real-time transport protocol (SRTP) and signaling encryption -- ensuring secure communication between itself and Cisco UCM -- as well as HTTPS for secure Web access, and password and PIN policies for enforcing password expiration, complexity and lockout features.

Unity Connection is licensed per user with the option for a basic user license that provides core functionality, like voicemail and messaging, or an enhanced user license that adds the Cisco Survivable Remote Site Voicemail capability for branch office users.

Instant messaging, presence and mobility

Cisco's IM and Presence Service integrates with Cisco UCM and third-party desktop and mobile presence and IM clients. It provides services to mobile users such as IM, real-time presence, click-to-call, call conferencing, voicemail, phone control and more.  Cisco's Jabber platform is the most popular client paired with the IM and Presence server, now supporting Windows operating systems, Android smartphones, iPhones, tablets and many more devices.

Similar to Unity Connection, Cisco's IM and Presence Service can be installed on a dedicated server that meets the minimum specifications or as a virtual server under a VMware environment. It supports a maximum of 45,000 users in a clustered environment. The product's Web interface is user-friendly, though some of the user administration is also performed via Cisco UCM -- only for UCM, IM and Presence installations.

Cisco's IM and Presence Service still provides enterprise-class IM and presence services for companies that are not using UCM for call control. In this case, the system can scale up to support up to 75,000 users.

With support for extensible messaging and presence protocol (XMPP) and SIP/SIMPLE, the IM and Presence server can support third-party applications that offer similar functions with Cisco Jabber.

Mobile users working securely without a VPN

Cisco Expressway helps businesses extend their UC services beyond the local network by enabling secure mobile access over public networks such as the Internet. With Cisco Expressway, users can make phone and video calls directly from their softphone without the need of a virtual private network (VPN). 

Expressway's firewall-traversal technology can provide all internal UC services to mobility users without a complicated VPN-based approach.

Expressway consists of two separate servers. One server, Expressway-C, is deployed internally, while the other, Expressway-E, is deployed in a demilitarized zone (DMZ). Mobile user connections or registrations are proxied through the two Expressway servers to UCM and are assigned their normal internal extension. The system supports up to 2,500 proxied registrations to UCM and up to 100 video or 200 audio calls.

In larger, more demanding environments, these figures can increase, depending on the selected hardware upon which the Expressway servers run.

Both versions of Cisco Expressway can be deployed either on two separate physical servers or virtualized machines. However, enterprises should ensure the wide area network (WAN) can support the Expressway's requirements. Load balancing and increased capacity is possible via multiple Expressway appliances or virtual machines.

As with all the above UC products, management of both Expressway servers is performed via a secure and simplified Web interface.

Finally, the Cisco UCM portfolio provides an extensive amount of services and applications. As with most vendors, licensing can become a bit of a headache, however, a properly provisioned communications network should simplify things while not breaking the budget.

Next Steps

Learn how to upgrade Cisco UC systems properly.

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