tailieunhanh - Bài giảng Mạng máy tính căn bản: Chương 3 - Phan Vĩnh Thuần

Bài giảng Mạng máy tính căn bản - Chương 3: Môi trường truyền dẫn cho networking giúp người học mô tả chi tiết kỹ thuật và màn trình diễn của các loại cáp, mô tả cáp đồng trục, ưu điểm và nhược điểm của các loại cáp, mô tả được bảo vệ xoắn đôi (STP) truyền hình cáp và ứng dụng của nó,. | Chương 3: MÔI TRƯỜNG TRUYỀN DẪN CHO NETWORKING Overview Copper cable is used in almost every LAN. Many different types of copper cable are available, with each type having advantages and disadvantages. Proper selection of cabling is key to efficient network operation. Phan Vĩnh Thuần Optical fiber is the most frequently used medium for the longer, high bandwidth, point-to-point transmissions required on LAN backbones and on WANs. Using optical media, light is used to transmit data through thin glass or plastic fiber. Electrical signals cause a fiber-optic transmitter to generate the light signals sent down the fiber. The receiving host receives the light signals and converts them to electrical signals at the far end of the fiber. However, there is no electricity in the fiber-optic cable itself. In fact, the glass used in fiber-optic cable is a very good electrical insulator. Phan Vĩnh Thuần Physical connectivity allowed an increase in productivity by allowing the sharing of | Chương 3: MÔI TRƯỜNG TRUYỀN DẪN CHO NETWORKING Overview Copper cable is used in almost every LAN. Many different types of copper cable are available, with each type having advantages and disadvantages. Proper selection of cabling is key to efficient network operation. Phan Vĩnh Thuần Optical fiber is the most frequently used medium for the longer, high bandwidth, point-to-point transmissions required on LAN backbones and on WANs. Using optical media, light is used to transmit data through thin glass or plastic fiber. Electrical signals cause a fiber-optic transmitter to generate the light signals sent down the fiber. The receiving host receives the light signals and converts them to electrical signals at the far end of the fiber. However, there is no electricity in the fiber-optic cable itself. In fact, the glass used in fiber-optic cable is a very good electrical insulator. Phan Vĩnh Thuần Physical connectivity allowed an increase in productivity by allowing the sharing of printers, servers, and software. Traditional networked systems require that the workstation remains stationary permitting moves only within the limits of the media and office area. The introduction of wireless technology removes these restraints and brings true portability to the computing world. Currently, wireless technology does not provide the high-speed transfers, security, or uptime reliability of cabled networks. However, flexibility of wireless has justified the trade off. Phan Vĩnh Thuần Administrators often consider wireless when installing a new network or when upgrading an existing network. A simple wireless network could be working just a few minutes after the workstations are turned on. Connectivity to the Internet is provided through a wired connection, router, cable or DSL modem and a wireless access point that acts as a hub for the wireless nodes. In a residential or small office environment these devices may be combined into a single unit Phan Vĩnh Thuần .