wide area network issues 1

Question 1

pareto principle

Answer 1

80-20 rule. In 90’s, 80% of network traffic stays local & 20% leaves the network. Now the opposite is true.

Question 2

3 categories of WAN connections

Answer 2

dedicated leased line, circuit switched connection, packet switched connection

Question 3

telephone network

Answer 3

a network of switches to establish a connection between the 2 parties wanting to communicate. comprised of end office, toll office, & intermediate switching office.

Question 4

voice circuit

Answer 4

the bandwidth needed to carry a telephone voice conversation (4000 Hz analog/64000 bps digital)

Question 5

circuit switching

Answer 5

communication takes place in 3 phases: circuit establishment, info transfer, circuit disconnect

Question 6

ISDN

Answer 6

integrated services digital network - a digital telephone tech that supporty multiple 64kbps channels on a single connection.

Question 7

ISDN categories

Answer 7

BRI/PRI - basic rate interface/primary rate interface.

Question 8

base rate interface

Answer 8

2 B channels + 1 D channel (16kbps)

Question 9

PRI

Answer 9

built on a T1 or E1 circuit. If T1 it has 23 B channels + 1 64kbps D channel.

Question 10

Frame relay

Answer 10

offers widespread availability & relatively low cost compared to leased lines.

Question 11

Frame relay sites connected via _____

Answer 11

virtual circuits

Question 12

virtual circuits can be ___ or ___ connections

Answer 12

point-to-point/point-to-mulitpoint

Question 13

Packet switching

Answer 13

long messages are broken up into a series of packets; each packet contains a portion of the data & control information like the destination address, sender address, etc.

Question 14

ATM

Answer 14

asynchronous transfer mode. layer 2 WAN tech that operates using the concept of permanent virtual circuits (PVCs) & switched virtual circuits (SVCs). Uses fixed-length cells as its protocol data unit (PDU)

Question 15

WAN media types

Answer 15

UTP, STP, coax, fiber optic, unguided transmission, radio, cellular phone, satellite

Question 16

WAN data rates (OC-1 & OC-3)

Answer 16

OC-1 = 51.84 mbps, OC-3 = 155.52 mbps

Question 17

Dedicated leased line

Answer 17

typically a point-to-point connection between 2 sites. All bandwidth on that line is available to those sites