Computer networks for the home and small business can be built using either wired or wireless technology. Wired Ethernet has been the traditional choice, but Wi-Fi wireless technologies are gaining ground fast. Both wired and wireless can claim advantages over the other; both represent viable options for local area networks (LANs).
Wi-Fi – Wireless LAN
LAN – Local Area Network
IP – Internet Protocol
ICS – Internet Connection Sharing
This presentation compares wired and wireless networking in the following five key areas:
• ease of installation
• total cost
About Wired LANs
Wired LANs use Ethernet cables and network adapters. Although two computers can be directly wired to each other using a crossover cable, wired LANs generally also need central devices like hubs, switches, or routers to accommodate more computers. For dial-up connections to the Internet, the computer hosting the modem must run Internet Connection Sharing or similar software to share the connection with all other computers on the LAN. Broadband routers allow easier sharing of cable modem or DSL Internet connections, plus they often include built-in firewall support.
Ethernet cables must be run from each computer to another computer or to the central device. It can be time-consuming and difficult to run cables under the floor or through walls, especially when computers sit in different rooms. Some newer homes are pre-wired with CAT5 cable, greatly simplifying the cabling process and minimizing unsightly cable runs. The correct cabling configuration for a wired LAN varies depending on the mix of devices, the type of Internet connection, and whether internal or external modems are used. However, none of these options pose any more difficulty than, for example, wiring a home theater system.
After hardware installation, the remaining steps in configuring either wired or wireless LANs do not differ much. Both rely on standard Internet Protocol and network operating system configuration options.
Ethernet cables, hubs and switches are very inexpensive. Some connection sharing software packages, like ICS, are free; some cost a nominal fee. Broadband routers cost more, but these are optional components of a wired LAN, and their higher cost is offset by the benefit of easier installation and built-in security features.
Ethernet cables, hubs and switches are extremely reliable, mainly because manufacturers have continually improved Ethernet technology for the past twenty years. Loose cables likely remain the single most common and annoying source of failure in a wired network. When installing a wired LAN or moving any of the components later, be sure to carefully check the cable connections.
Broadband routers have also suffered from some reliability problems in the past. Unlike other Ethernet gear, these products are relatively new, multi-function devices. Broadband routers have matured over the past several years and their reliability has improved greatly.
Wired LANs offer superior performance. Traditional Ethernet connection offer only 10 Mbps bandwidth, but 100 Mbps Fast Ethernet technology costs little more and is readily available. Although 100 Mbps represents a theoretical maximum performance never really achieved in practice, Fast Ethernet should be sufficient for home file sharing, gaming, and high-speed Internet access for many years into the future.
Wired LANs utilizing hubs can suffer performance slowdown if computers heavily utilize the network simultaneously. Use Ethernet switches instead of hubs to avoid this problem; a switch costs little more than a hub.
For any wired LAN connected to the Internet, firewalls are the primary security consideration. Wired Ethernet hubs and switches do not support firewalls. However, firewall software products like ZoneAlarm can be installed on the computers themselves. Broadband routers offer equivalent firewall capability built into the device, configurable through its own software.
Comparing wireless LAN technology with wired
About Wireless LANs
Popular WLAN technologies all follow one of the three main Wi-Fi communication standards. The benefits of wireless networking depend on the standard employed:
• 802.11b was the first standard to be widely used in WLANs.
• The 802.11a standard is faster but more expensive than 802.11b; 802.11a is more commonly found in business networks.
• The newest standard, 802.11g, attempts to combine the best of both 802.11a and 802.11b, though it too is more a more expensive home networking option.
Wi-Fi networks can be configured in two different ways:
• "Ad hoc" mode allows wireless devices to communicate in peer-to-peer mode with each other.
• "Infrastructure" mode allows wireless devices to communicate with a central node that in turn can communicate with wired nodes on that LAN.
Most LANs require infrastructure mode to access the Internet, a local printer, or other wired services, whereas ad hoc mode supports only basic file sharing between wireless devices.
Both Wi-Fi modes require wireless network adapters, sometimes called WLAN cards. Infrastructure mode WLANs additionally require a central device called the access point. The access point must be installed in a central location where wireless radio signals can reach it with minimal interference. Although Wi-Fi signals typically reach 100 feet (30 m) or more, obstructions like walls can greatly reduce their range.
Ďaľšie referáty z kategórie
IT: WIRED VS WIRELESS NETWORKING
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Zdroje: ŽID, Norbert [et al.]. Orientace ve světě informatiky. Praha : Management Press, 1998. 391 s. ISBN 80-85943-58-1., SATRAPA, Pavel. IPv6: Internet Protokol verze 6. Praha : Neocortex, 2002. 238 s. ISBN 80-86330-10-9.