Interactive Summary-Chapter 5

Section-A

Networks can be classified by geographical scope as PANs, LANs, MANs, NANs, and WANs.  LAN technologies are standardized by the IEEE organization.   Each concept point on a network is referred to as a node and can contain computers, networked peripherals, or network devices.  Computers connected to a network require network circuitry, often housed on a network interface card (NIC).  Networks that include one or more servers can operate in client/server mode or peer-to-peer mode.

Networks without a server typically operate in peer-to-peer mode.  Physical network topologies include star, bus, ring, mesh, and tree.  Network nodes are linked by communications channels.  High bandwidth channels are referred to as broadband, whereas low bandwidth channels are referred to as narrowband.  Communications protocols, such as TCP/IP, divide messages into packets, handle addressing, and manage routing.

Section-B

Wired networks are fast, secure, and simple to configure.  HomePNA networks transport data over telephone wiring and HomePlug networks transport data over electrical wiring.  Ethernet networks use CAT5 or CAT6 wiring with plastic RJ45 connectors.

Ethernet uses CSMA/CD protocol to detect collisions.  Fast Ethernet operates at 100 Mbps, whereas Gigabit Ethernet operates at 1000 Mbps.  Ethernet is usually wired in a star topology to a central device.  A network hub is a device that accepts data from one workstation and broadcasts it to all of the other

network nodes.

A network switch is a more sophisticated connection device that sends data only to the devices  specified as the destination.  A network router is a network device that can ship data from one network to another.  You typically use your browser software to access the router’s configuration utilities.

Section-C

Most wireless LANs transport data using radio frequency signals.  The most popular WLAN technology is Wi-Fi, but Bluetooth is used for PANs, and other short-range connections.  Wi-Fi is defined by the IEEE 802.11 standards, and there are versions denoted by the letters a, b, g, and n.  Computers on a Wi-Fi network must have wireless circuitry , such as a Wi-Fi adapter.  Wireless networks can be set up as a wireless ad-hoc network in which devices broadcast directly to each other, or as a wireless infrastructure network that uses a centralized broadcasting device, such as a wireless access point or a wireless router.  When setting up a wireless network it is important to change the default router password, create an SSID to uniquely identify the network, and enable wireless encryption for security.