Chapter 10: The Internet Flashcards
What is the basic structure of the Internet?
The internet in basic terms is a network of networks and consists of 3 ISP (internet service provider) tiers. Tier 1 ISPs are the highest-level ISPs known as national ISPs and are connected by IXPs (internet exchange points). The next level is Tier 2 ISPs, or regional ISPs. Tier 2 rely on Tier 1 ISPs to transmit their data to other countries. Tier 2 supply their services to Tier 1 ISPs, which in turn sell their services to the users.
Compare and contrast cable modem and DSL.
DSL (Digital Subscriber line) uses the local loop telephone service and is a point to point technology. Cable modem, on the other hand, uses coaxial cable or a hybrid with fiber optic cables and are not point to point. The line with a cable modem are shared multipoint circuits, which mean that you will be competing with your neighbors and other users.
Explain how WiMAX works.
Worldwide Interoperability for Microwave Access (WiMAX), or IEEE 802.16, is similar to 802.11 Wi-Fi and is used to connect homes and businesses to the internet. However, the future of WiMAX, is to be used in laptops and mobile devices to connect to the internet. Essentially, your mobile device will contain a WiMAX that will be used to connect to an access point. Since WiMAX is a share multipoint architecture, devices will have to wait for the AP to be available.
What is Internet2 ® ?
Internet2 is a collaborative effort between 400 universities, corporations, government agencies, and other organizations from more than 100 countries to develop new technologies and innovations for research and education.
What is a gigapop?
A Point of Presence that provides gigabit speeds for the Internet2 collaboration. It provides connections for layer 1, 2, or 3.
What is peering?
In general, ISPs at the same level do not charge one another for transferring messages they exchange. That is, a national tier 1 ISP does not charge another national tier 1 ISP to transmit its messages.
Point of Presence (POP)
A POP is simply the place at which the ISP provides services to its customers. To connect to the internet, a customer must establish a circuit from his or her location into the ISP POP.
What is a local loop?
Digital subscriber line (DSL) is a family of point-to-point technologies designed to provide high-speed data transmission over traditional telephone lines. The actual cable used in the LOCAL LOOP doe not need to be changed.
What are the types of DSL
1. Asymmetric DSL (ADSL) uses frequency division multiplexing to create three separate channels over the one local loop circuit. One channel is the traditional voice telephone circuit. A second channel is a relatively high-speed data channel downstream from the carrier's end office to the customer. The third channel is a slightly slower data channel upstream from the customer to the carrier's end office. Maximum Downstream/Maximum Upstream 3 Mbps/512 Kbps 6 Mbps/640 Kbps 12 Mbps/1.5 Mbps 18 Mbps/1.5 Mbps 24 Mbps/3 Mbps
