Chapter 10 - The Internet

Question 1

National ISPs, called ___________, connect together and exchange data at Internet exchange points (IXPs)

Answer 1

tier 1 ISPs

Question 2

In the early 1990s, the _____________ established four main IXPs in the United States to connect the major tier 1 ISPs

Answer 2

National Science Foundation (NSF)

Question 3

Regional ISPs like Comcast or BellSouth, sometimes called ____________ , provide services for customers.

Answer 3

tier 2 ISPs

Question 4

________________ sell Internet access to individuals.

Answer 4

Tier 3 ISPs

Question 5

Peering is:

Answer 5

a voluntary arrangement where two or more separate networks agree to directly exchange internet traffic with each other to improve performance and reduce costs.

Question 6

TF: Higher-level ISPs charge lower-level ISPs to transmit their data

Answer 6

True

Question 7

A ____________ is the place at which the ISP provides services to its customers.

Answer 7

point of presence (POP)

Question 8

Today, the backbone circuits of the major U.S. national ISPs operate at ________________.

Answer 8

SONET OC-192 (10 Gbps)

Question 9

As traffic increases, ISPs can add more and faster circuits relatively easily, but where these circuits come together at IXPs, _______________ are becoming more common.

Answer 9

bottlenecks

Question 10

DSL and cable modem technologies are commonly called _______________ because they provide higih-speed communications.

Answer 10

broadband technologies

Question 11

TF: Unlike the WAN technologies in the previous chapter, Internet access technologies cannot be used for general-purpose networking from any point to any point.

Answer 11

True

Question 12

What are the three principal Internet access technologies?

Answer 12

DSL, cable modem, and fiber.

Question 13

_________________ is a family of point-to-point technologies designed to provide high-speed data transmission over traditional telephone lines.

Answer 13

Digital subscriber line (DSL)

Question 14

_____________________ uses the existing local loop cable but places different equipment on the customer premises (i.e., the home or office) and in the telephone company end office.

Answer 14

Architecture DSL

Question 15

In Architecture DSL, ____________ is installed at the customer location. This includes a line splitter that is used to separate the traditional voice telephone transmission from the data transmissions.

Answer 15

customer premises equipment (CPE)

Question 16

A _________________ is both a modem and a frequency division multiplexing (FDM) multiplexer.

Answer 16

DSL modem (sometimes called a DSL router)

Question 17

The most common type of DSL today is __________________.

Answer 17

asymmetric DSL (ADSL)

Question 18

Describe asymmetric DSL (ADSL)

Answer 18

ADSL uses FDM 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. ADSL is called asymmetric because its two data channels have different speeds. Each of the two data channels is further multiplexed using time division multiplexing so they can be subdivided.

Question 19

The ________________ is a digital service offered by cable television companies.

Answer 19

cable modem

Question 20

DOCSIS is the dominant standard for cable modems. What does the acronym stand for?

Answer 20

Data over Cable Service Interface Specification

Question 21

How are cable modems different from DSL?

Answer 21

DSL is a point-to-point technology, whereas cable modems use shared multipoint circuits. With cable modems, each user must compete with other users for the available capacity. Furthermore, because the cable circuit is a multipoint circuit, all messages on the circuit go to all computers on the circuit.

Question 22

Describe the most common architecture for cable modems.

Answer 22

The cable TV circuit enters the customer premises through a cable splitter that separates the data transmissions from the TV transmissions and sends the TV signals to the TV network and the data signals to the cable modem. The cable modem (both a modem and frequency division multiplexer) translates from the cable data into Ethernet packets, which then are directed into a computer to a router for distribution in a small network. As with DSL, cable modem companies usually combine all of these separate devices into one or two devices to make it easier for the home consumer to install.

Question 23

With a cable modem, the cable TV wiring entering the customer premises is _______________________.

Answer 23

a standard coaxial cable

Question 24

With a cable modem, the coax cable runs to a fiber node, which has an ________________________ to convert between the coaxial cable on the customer side and fiber-optic cable on the cable TV company side.

Answer 24

optical-electrical (OE) converter

Question 25

With a cable modem, the fiber modes are connected to the cable company ___________ through two separate circuits: an upstream circuit and a downstream circuit.

Answer 25

distribution hub (sometimes called a headend)

Question 26

With a cable modem, the upstream circuit that contains data traffic from the customer is connected to a _________________ .

Answer 26

cable modem termination system (CMTS)

Question 27

With a cable modem, the downstream circuit to the customer contains both ____________________ and ___________________.

Answer 27

ordinary video transmissions from the cable TV video network and data transmissions from the Internet.

Question 28

With DOCSIS, the maximum speed is about _______________ downstream and about ________________ upstream.

Answer 28

200 Mbps downstream and 200 Mbps upstream

Question 29

Most cable TV companies provide at most ________________ downstream and ______________ upstream.

Answer 29

50 Mbps downstream and 10 Mbps upstream

Question 30

FTTH stands for:

Answer 30

Fiber to the Home

Question 31

With FTTH, a _________________ acts like a DSL modem or cable modem at each subsrciber location and converts the signals in the optical network into an Ethernet format.

Answer 31

optical network unit (ONU)

Question 32

FTTH is a dedicated point-to-point service like ___________ .

Answer 32

DSL

Question 33

With FTTH, most common carriers offer _______________ services both up and down.

Answer 33

1 Gbps

Question 34

The closest thing the Internet has to an owner is the ____________, which is an open-membership professional society with about 150 organizational members and 65,000 individual members in more than 100 countries, including corporations, government agencies, and foundations that have created the Internet and its technologies.

Answer 34

The Internet Society

Question 35

The mission of The Internet Society is:

Answer 35

to ensure “the open development, evolution and use of the Internet for the benefit of all people throughout the world.”

Question 36

_________________________ is a large, open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. It works through a series of working groups, which are organized by topic (e.g., routing, transport, and security).

Answer 36

The Internet Engineering Task Force (IETF)

Question 37

______________________ is responsible for technical management of IETF activities and the Internet standards process. It administers the process according to the rules and procedures that have been ratified by the Internet Society trustees.

Answer 37

The Internet Engineering Steering Group (IESG)

Question 38

The ______________________ attempts to develop conclusions on strategic issues (e.g., top-level domain names, use of international character sets) that can be passed on as guidance to the IESG or turned into published statements or simply passed directly to the relevant IETF working group.

Answer 38

Internet Architecture Board (IAB)

Question 39

______________________ research groups work on long-term issues related to Internet protocols, applications, architecture, and technology.

Answer 39

The Internet Research Task Force (IRTF)

Question 40

____________________ comprises about 400 universities, corporations, government agencies, and organizations from more than 100 countries with a primary focus to develop advanced networking as well as other innovative technologies for research and education.

Question 41

The access points in Internet2 are called _______________ because they provide a POP at gigabit speeds.

Answer 41

gigapops