4.3 Compare and contrast the different network types
A high-speed, high-capacity Internet and data connection
Digital Subscriber Line
DSL uses twisted copper and a DSL modem for high-speed data and voice communication. Transmission is made over the existing phone line up to an approximate 18,000 ft. ADSL (asynchronous) and SDSL (synchronous) are the most popular. ASDL has slower upload and faster download speeds while SDSL upload and download speeds are equal but the service may be more expensive.
Cable broadband access provides connectivity from the Internet service provider to an end user through the use of a cable modem and coaxial cable. The service is typically integrated into the cable television infrastructure and capable of transmitting distances of up to 100 miles. Downstream bit rates can range from 100 to 400 Mbit/s while upstream traffic ranges from 384kbit/s to more than 20Mbit/s.
Requires specialized equipment. Experiences long latency. Speeds up to 5 MB/s
Satellite broadband offers two-way Internet access via satellites. Through a special satellite modem, requests are sent first to a local satellite dish, then to a satellite located some 22,000 miles in space, and back again. Satellite broadband, while slower in both the uplink and downlink than DSL Internet service, allows Internet access at high speeds that range from 200 kilobits per second to 100 megabits per second. It is also available in remote areas where other services may not be.
A transmission technique that utilizes bursts of light to transmit data.
Modem uses standard phone line. Modulator/demodulator. Limited bandwidth. Data transfer speed based on current V.90 and V.92 standards. Download speeds for both standards is limited to 56 Kbps, while upload speed for V.90 is up to 33.6 Kbps and for V.92 is up to 48 Kbps.
All 802.11 types
2.4GHz / 5GHz
Note: 802.11b and 802.11g are subject to interferrence from other equipment operating at the 2.4 GHz range, including microwave ovens, Bluetooth devices, and cordless telephones.
Note: 802.11g and 802.11n are both backwards compatible.
Uses 40-bit and 104-bit encryption but has serious security flaws and is easily compromised.
Uses an encryption key integrity-checking feature and user authentication through EAP (Extensible Authentication Protocol). More secure than WEP but less than WPA2 which uses the AES (Advanced Encryption Standard) for wireless security.
An SSID is the name of a wireless local area network (WLAN). All wireless devices on a WLAN must employ the same SSID in order to communicate with each other.
The SSID on wireless clients can be set either manually, by entering the SSID into the client network settings, or automatically, by leaving the SSID unspecified or blank. A network administrator often uses a public SSID, that is set on the access point and broadcast to all wireless devices in range. Some newer wireless access points disable the automatic SSID broadcast feature in an attempt to improve network security.
SSIDs are case sensitive text strings. The SSID is a sequence of alphanumeric characters (letters or numbers). SSIDs have a maximum length of 32 characters.
Media Access Control filtering, also known as layer 2 address filtering, refers to a security access control method in which the 48-bit address assigned to each network card is used to approve or deny access to the network.
A system for mobile phones allowing fast connection, Internet access, digital photography, graphics transmission and display, and other advanced features