A firewall is a device or set of devices designed to permit or deny network transmissions based upon a set of rules and is frequently used to protect networks from unauthorized access while permitting legitimate communications to pass. wikipedia.org

A virtual private network (VPN) is a network that uses primarily public telecommunication infrastructure, such as the Internet, to provide remote offices or traveling users access to a central organizational network. wikipedia.org

Cisco ASA 5500 Series Adaptive Security Appliances, or simply Cisco ASA 5500 Series, is Cisco's line of network security devices introduced in 2005. wikipedia.org

Cisco Systems, Inc. is an American multinational corporation that designs, manufactures, and sells networking equipment. It has a full range of router products from small business to enterprise solutions, typically using its own Cisco IOS operating system. wikipedia.org

Cisco Certified Network Associate (CCNA) Routing and Switching is a certification program for entry-level network engineers that helps maximize your investment in foundational networking knowledge.

"The CCNP is the credential that validates the ability to work with medium-sized networks (between 100 and 500 end devices) and with technology such as QoS, broadband, VPNs, and security-minded features."

Cisco Unified Communications Manager (CUCM), formerly Cisco Unified CallManager and Cisco CallManager (CCM), is a software-based call-processing system developed by Cisco Systems. wikipedia.org