may be used to share the broadband connections between secured corporate access and unsecured Internet access at the same time.

Authentication: Authentication defines who gains access to resources. Identity-based network services using authentication, authorization, and accounting (AAA) servers, 802.1X port-based access control, Cisco security, and trust agents are used.

Quality of Service (QoS): QoS mechanisms prioritize the traffic, optimize WAN bandwidth usage, balance the differences in uplink and downlink speed of broadband connections, and ensure adequate performance for applications that are sensitive to delay and jitter (for example, voice and video).

Management: Network management techniques meet the challenges brought by the complexity of support over a broadly based remote network and the loss of corporate control that such topologies bring. Information Technology (IT) staff centrally manage and support teleworker connections and equipment, and transparently configure and push security and other policies to the remote devices. Tools are available that implement performance and fault management and monitor service level agreements (SLAs).

Content 2.1 Describing Remote Connection Topologies for Teleworkers 2.1.4 Components of the Teleworker Solution The teleworker solution has three major components: home office, corporate, and optional IP telephony components:

The required home office components are broadband access (cable or DSL), a remote VPN router with QoS functionality, and a laptop or desktop computer. Additional components might be a Wireless Access Point or video devices. When traveling, teleworkers need an Internet connection and a VPN client to connect to the corporate network.
Corporate components are VPN headend routers, VPN concentrators or multifunction security appliances such as the Cisco Adaptive Security Appliance (ASA), authentication, and central management devices for resilient aggregation and termination of the IPsec VPN tunnels.
The optional corporate IP telephony components are Cisco Unified CallManager for call processing, signaling, and device control; voice gateway for interconnection of traditional phone networks with VoIP environment; IP phones for voice and added value services; Cisco video telephony (VT) camera: voice messaging platform for diverse message consolidation; and Cisco Contact Center for advanced call treatment.

Content 2.1 Describing Remote Connection Topologies for Teleworkers 2.1.5 Traditional Versus Business-Ready Teleworker Requirements The traditional teleworker solution uses a software VPN client on the remote user laptop or desktop PC. This solution has these disadvantages:

There is a lower level of accessibility; for example, the inability to deploy and support advanced applications, such as voice, video, and videoconferencing.
There is no QoS for efficient delivery and prioritization of traffic.
There may be inadequate security because most of the security responsibility relies on the end user, leaving little or no control to IT staff.
There is an absence of controlled configuration, management, and support by IT staff.

Figure shows how Cisco’s Business-Ready Teleworker solution overcomes all the problems of the traditional teleworker solution.

Content 2.2 Describing Cable Technology 2.2.1 What is a Cable System? Cable television (TV) first began in Pennsylvania in 1948. John Walson, the owner of an appliance store in a small mountain town, needed to solve poor over-the-air reception problems experienced by customers trying to receive TV signals from Philadelphia through the mountains. Walson erected an antenna on a utility pole on a local mountaintop that enabled him to demonstrate the televisions in his store with strong broadcasts coming from the three Philadelphia stations. He connected the antenna to his appliance store via a cable and modified signal boosters. He then connected several of his customers who were located along the cable path. This was the first community antenna television (CATV) system in the United States. Walson’s company grew over the years, and he is recognized as the founder of the cable television industry. He was also the first cable operator to use microwave to import distant television stations, the first to use coaxial cable to improve picture quality, and the first to distribute pay television programming (HBO). The “cable” in cable system refers to the coaxial cable that carries radio frequency (RF) signals across the network. Coaxial cable is the primary medium used to build cable TV systems. A typical cable operator now uses a satellite dish to gather TV signals. Early systems were one-way with cascading amplifiers placed in series along the network to compensate for signal loss. Taps were used to couple video signals from the main trunks to subscriber homes via drop cables . Modern cable systems provide two-way communication between subscribers and the cable operator. Cable operators now offer customers advanced telecommunications services including high-speed Internet access, digital cable television, and residential telephone service.

Content 2.2 Describing Cable Technology 2.2.2 Cable Technology Terms The following terms describe key cable technologies:

Broadband: Broadband transmission methods send multiple pieces of data simultaneously to increase the effective rate of transmission. In cable systems, broadband refers to the frequency-division multiplexing (FDM) of many signals in a wide RF bandwidth over a hybrid fiber-coaxial (HFC) network and the capability to handle vast amounts of information.
Community antenna television (CATV): The original meaning of the term CATV changed over the years. The term now widely refers to residential cable systems.
Coaxial cable: Coaxial cable transports RF signals and has certain physical properties that define the attenuation of the signal. These properties include cable diameter, dielectric construction, ambient temperature, and operating frequency. It consists of a center conductor surrounded by insulation and an outside ground shield of braided wire. The shield is designed to minimize electrical and RF interference.
Tap: A tap divides the input signal's RF power to support multiple outputs. Typically, the cable operators deploy taps with two, four, or eight ports called subscriber drop connections.
Amplifier: An amplifier magnifies an input signal and produces a significantly larger output signal.
Hybrid fiber-coaxial (HFC): HFC is a mixed optical-coaxial network in which optical fiber replaces the lower bandwidth coaxial where useful in the traditional trunk portion of the cable network.
Downstream: This is the direction of an RF signal transmission (TV channels and data) from the source (headend) to the destination (subscribers). Transmission from source to destination is called the forward path.
Upstream: This is the direction of an RF signal transmission opposite to downstream: from subscribers to the headend, or the return or reverse path.

Content 2.2 Describing Cable Technology 2.2.3 Cable System Components CATV distributes TV channels collected at a central location, called a headend, to subscribers over a branched network of optical fibers, coaxial cables, and broadband amplifiers. Since the early 1990s, the most common architecture is the HFC network. There are five major components of a modern cable system: –

Antenna site: The location of an antenna site is chosen for optimum reception of over-the-air, satellite, and sometimes point-to-point signals. The main receiving antennas and satellite dishes are located at the antenna site.
Headend: The headend is a master