IT_Chapter_10A

Wired Internet Connections

• Dial-up connections

– Standard phone lines and a modem

– Computer dials a number for your ISP

– All Internet programs use the connection

– Applications might need configured

• High-speed broadband connections

– Any connection faster than dialup

– Networks share the broadband connection

• All users access the same connection

• T or DSL lines common

– Home use increasing due to

• Lower cost

• Increased availability

• ISDN

– Offers speeds up to 1.5 Mbps

– Uses standard phone lines

– Requires special equipment

– Simultaneous use of phone and data

• DSL

– Offers speeds up to 30 Mbps

– Uses modified phone lines

• Needs special DSL modem

– Simultaneous use of phone and data

– Asynchronous DSL

• Different up and download speeds

– Synchronous DSL

– Variable DSL

• Speed changes based on traffic

• Cable modems

– Speeds up to 3 Mbps

– Uses cable TV wires

– Requires a cable modem

– Simultaneous use of TV and data

Software Accessing The Internet

• Application programming interface (API)

– Simplifies connection to network devices

– Allows any application to access Internet

– UNIX API uses sockets

– Windows API uses winsock

• Network drivers

– Control access to the hardware

– Ethernet and dial-up require a driver

– API connects to the driver

Wireless Internet Connection

• Wireless WAN (WWAN)

– Wireless network over a large area

– Uses radio signals to transfer data

– Speeds range from 1 to 100 Mbps

– Antennas required

– Subject to atmospheric disturbances

• Satellite services

– Internet access in remote regions

– Suitable for home and office use

– Needs a VSAT at the client

• Very Small Aperture Terminal

• Connects to the satellite

– Modem connects to the VSAT

• Wireless LANs (WLAN)

– Network without wires

– Connects to a broadband LAN connection

– WAP are wired directly into the LAN

– Nodes use wireless

• Wireless security

– Crucial to protect wireless transmissions

– Encryption protects transmissions

– Wireless Encryption Protocol is quite weak

– Wi-Fi Protected Access is stronger

– MAC address of trusted computers

– War driving