IT Manager's Handbook: Getting Your New Job Done
This is a how to be an IT manager book, and it covers every area possible and then some.
TABLE OF CONTENTS IT Manager's Handbook: Getting Your New Job Done
Section 10.9: WAN: What Are the Key WAN Technologies I Should Know?
10.9 WAN: What Are the Key WAN Technologies I Should Know?
When designing a WAN strategy, it is important to know of the different connectivity options available to you. In general there are four types of options:
- Point-to-point circuits
- Dial-up
- Packet switching
- Cable modems
Point-to-Point Circuits
Point-to-point circuits, also known as leased, dedicated, and private lines, are facilities from telecom carriers that provide a connection between two locations. Point-to-point circuits can connect sites that are across town or across the country.
The primary advantage of a leased line is that it is always up, 24 hours a day. The cost is fixed and does not vary by usage. Since the line is dedicated, when there is a problem with the service the telephone company can investigate, locate, and resolve it (unlike a staticky dial-up connection, which is only resolved by hanging up and dialing again).
The most popular leased lines are T-1 and T-3. A T-1 line consists of 24 channels, each of which can provide 64 Kbps, for an aggregate throughput of 1.544 Mbps. A T-3 line is a leased line that provides data transmission speeds of 44.736 Mbps, via 672 circuits, each of which can support 64 Kbps transmissions. Quite often, a company will use a "fractional" T-1 or T-3. A fractional line is one that uses only a portion of the available channels. While this reduces the throughput, there is also a significant cost savings.
Dial-up Lines
Everyone is familiar with dial-up lines like the ones they...
Copyright Bill Holtsnider and Brian D. Jaffe 2001 under license agreement with Books24x7
