Chapter 4

Question 1

What are the four processes the Network layer uses to provide end-to-end access?

Answer 1

1. Addressing
2. Encapsulation
3. Routing
4. Decapsulation

Question 2

What is the purpose of the Network layer?

Answer 2

The network layer packages L4 segments and add a logical address. It passes packets with minimal overhead and divides networks into groups to manage data flow.

Question 3

There are three charastics to IPv4 and IPv6 protocols, what are they?

Answer 3

1. Connectionless
2. Best Effort
3. Media Independant

Question 4

What is ‘Connectionless’ transmissions?

Answer 4

No connection is made before the data is sent to assure the receiving end is online.

Question 5

What is ‘Best Effort’ transmission?

Answer 5

IP does not guarantee that all packets will be received.

Question 6

What is ‘Media Independent’ transmission?

Answer 6

IP Packets are unaware of the media used to transmit packets.

Question 7

What four items compose an IPv4 Packet?

Answer 7

1. The Source and Destination IP
2. Time to Live (TTL)
3. Differentiated services
4. Protocol

Question 8

Describe the TTL in an IPv4 packet.

Answer 8

An 8-bit long indication to the “Lifespan” of a packet. At each hop, the TTL goes down by one.

Question 9

What are the three most common IPv4 Protocols?

Answer 9

01: ICMP
06: TCP
17: UDP

Question 10

What is Differentiated services in an IPv4 packet?

Answer 10

Quality of Service (QoS)

Question 11

What is Bandwidth

Answer 11

The Theoretical Maximum Speed for transmitting information.

Question 12

What is Throughput

Answer 12

The actual speed of transmitting information.

Question 13

What is Goodput

Answer 13

The speed of all successful network transmissions.

Question 14

What is the primary difference between Synchronous and Asynchronous signaling?

Answer 14

Sync. sends packets in order on a set timing schedule, while Async. sends packets all at once with no timing.

Question 15

What is EMI?

Answer 15

Electromagnetic interference: signals that can distort and/or corrupt the data sent over copper media.

Question 16

What is RFI?

Answer 16

Radio frequency interference: signals that can distort and/or corrupt the data sent over copper media.

Question 17

What is Crosstalk?

Answer 17

Crosstalk is a disturbance caused by the electric or magnetic fields of a signal on one wire to the signal in an adjacent wire.

Question 18

What are the three types of copper media?

Answer 18

UTP, STP, and Coax.

Question 19

What is the largest Pro of using Fiber over Copper?

Answer 19

Fiber is faster and is completely immune to EMI, RFI, and Crosstalk.

Question 20

What is the largest Con of using Fiber over Copper?

Answer 20

Fiber is much more expensive and harder to terminate.

Question 21

What is the difference between Single Mode and Multimode Fiber?

Answer 21

Single Mode allows for only a single path for light to travel. Multimode allows for multiple paths for light to travel.

Question 22

What type of copper cable would you use to connect a Computer to a Switch?

Answer 22

Straight-through.

Question 23

What type of copper cable would you use to connect a Computer to a Router?

Answer 23

Crossover.

Question 24

What type of cable would you use to connect a PC to a Cisco Router or Switches Console Port?

Answer 24

Rollover.

Question 25

What is the difference between CSMA/CD and CSMA/CA?

Answer 25

CD is Collision Detection, while CS is Collision Avoidance.

Question 26

What is CSMA/CD?

Answer 26

Collision detection works by checking the media for a data signal. If there is a signal on the line the device has to wait and try again later. If a collision occurs, the two senders back off and receive a random amount of time to time-out.

Question 27

What is CSMA/CA?

Answer 27

With Collision Avoidance, the device checks the media for a signal and sends a notification of its intent to use it. After the notification, the device then sends the data.

Question 28

What device will prevent Collision and never rarely needs to use CSMA/CD?

Answer 28

Switches.

Question 29

What is CSMA?

Answer 29

Carrier Sense Multiple Access was first used to detect if the media is carrying a signal. If two devices transmit at the same time; data collision occurs.