Lecture CCNA Exploration 4.0 (Kỳ 4) - Chapter 6: Teleworker services

Describe the enterprise requirements for providing teleworker services, including the differences between private and public network infrastructures. Describe the teleworker requirements and recommended architecture for providing teleworking services. Explain how broadband services extend enterprise networks using DSL, cable, and wireless technology,...
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Lecture CCNA Exploration 4.0 (Kỳ 4) - Chapter 6: Teleworker servicesChapter 6 - Teleworker Services CCNA Exploration 4.0 1Introduction Học viện mạng Bach Khoa - Website: www.bkacad.com 2Business Requirements for Teleworker Services Học viện mạng Bach Khoa - Website: www.bkacad.com 3The Business Requirements for Teleworker Services• When designing network architectures that support a teleworking solution, designers must balance organizational requirements for security, infrastructure management, scalability, and affordability against the practical needs of teleworkers for ease of use, connection speeds, and reliability of service. Học viện mạng Bach Khoa - Website: www.bkacad.com 4The Teleworker Solution• The term broadband refers to advanced communications systems capable of providing high-speed transmission of services, such as data, voice, and video, over the Internet and other networks.• Transmission is provided by a wide range of technologies, including digital subscriber line (DSL) and fiber-optic cable, coaxial cable, wireless technology, and satellite. Học viện mạng Bach Khoa - Website: www.bkacad.com 5The Teleworker Solution• Soon, voice over IP (VoIP) and videoconferencing components will become expected parts of the teleworkers toolkit.• Home Office Components - The required home office components are a laptop or desktop computer, broadband access (cable or DSL), and a VPN router or VPN client software installed on the computer. Additional components might include a wireless access point. When traveling, teleworkers need an Internet connection and a VPN client to connect to the corporate network over any available dialup, network, or broadband connection.• Corporate Components - Corporate components are VPN-capable routers, VPN concentrators, multifunction security appliances, authentication, and central management devices for resilient aggregation and termination of the VPN connections. Học viện mạng Bach Khoa - Website: www.bkacad.com 6Broadband Services Học viện mạng Bach Khoa - Website: www.bkacad.com 7 Connecting Teleworkers to the WAN• The choice of access network technology and the need to ensure suitable bandwidth are the first considerations to address when connecting teleworkers. Học viện mạng Bach Khoa - Website: www.bkacad.com 8Connecting Teleworkers to the WAN Học viện mạng Bach Khoa - Website: www.bkacad.com 9Cable Học viện mạng Bach Khoa - Website: www.bkacad.com 10Cable Học viện mạng Bach Khoa - Website: www.bkacad.com 11Cable Học viện mạng Bach Khoa - Website: www.bkacad.com 12Cable• The Data-over-Cable Service Interface Specification (DOCSIS) is an international standard developed by CableLabs, a non-profit research and development consortium for cable-related technologies.• DOCSIS specifies the OSI Layer 1 and Layer 2 requirements: – Physical layer - For data signals that the cable operator can use, DOCSIS specifies the channel widths (bandwidths of each channel) as 200 kHz, 400 kHz, 800 kHz, 1.6 MHz, 3.2 MHz, and 6.4 MHz. DOCSIS also specifies modulation techniques (the way to use the RF signal to convey digital data). – MAC layer - Defines a deterministic access method, time-division multiple access (TDMA) or synchronous code division multiple access method (S-CDMA). Học viện mạng Bach Khoa - Website: www.bkacad.com 13Cable Học viện mạng Bach Khoa - Website: www.bkacad.com 14Học viện mạng Bach Khoa - Website: www.bkacad.com 15DSL• DSL is a means of providing high-speed connections over installed copper wires.• Several years ago, Bell Labs identified that a typical voice conversation over a local loop only required bandwidth of 300 Hz to 3 kHz.• Advances in technology allowed DSL to use the additional bandwidth from 3 kHz up to 1 MHz to deliver high-speed data services over ordinary copper lines.• The two basic types of DSL technologies are asymmetric (ADSL) and symmetric (SDSL).• The transfer rates are dependent on the actual length of the local loop, and the type and condition of its cabling. For satisfactory service, the loop must be less than 5.5 kilometers (3.5 miles). Học viện mạng Bach Khoa - Website: www.bkacad.com 16 DSL• The two key components are the DSL transceiver and the DSLAM: – Transceiver - Connects the computer of the teleworker to the DSL. Usually the transceiver is a ...