Section 3: Host to Host Communications

Question 1

TCP/IP Stack Layers

Answer 1

• Application
• Transport
• Internet
• Network Access

Question 2

Cisco TCP/IP Stack Layer Definition: Appication

Answer 2

• represents data users, encodes, and controls the dialog

Question 3

Cisco TCP/IP Stack Layer Definition: Transport

Answer 3

• supports communication between end devices across a diverse network

Question 4

Cisco TCP/IP Stack Layer Definition: Internet

Answer 4

• provides logical addressing and determines the best path through the network

Question 5

Cisco TCP/IP Stack Layer Definition: Network Access

Answer 5

• controls the hardware devices and media that make up the network

Question 6

At what layer is data transmitted between hosts?

Answer 6

• Application

Question 7

At what layer is the ‘segment’ transmitted between hosts?

Answer 7

• Transport

Question 8

At what layer is the ‘packet’ transmitted between hosts?

Answer 8

• Internet

Question 9

At what layer is the ‘frame’ transmitted between hosts?

Answer 9

• Network Access

Question 10

PDU

Answer 10

• What hosts send back and forth for communicating
• Protocol Data Unit
• The entire communication of the OSI stack
• Often referred to as ‘packet’, but that is not entirely correct since this is the entire communication, and ‘packet’ is technically only at layer 3 (Internet/Network)

Question 11

Layer 7

Answer 11

• Application layer
• provides network services to the applications of the user
• does not provide services to any other layers of the OSI model (only layer that does not provide services to other layers)
• establishes the availability of intended communication partners
• synchronizes and establishes agreement on procedures for error recovery and control of data integrity

Question 12

Layer 6

Answer 12

• Presentation Layer
• ensures the information that is sent at the application layer of one system is readable by the application layer of another system
• can translate among multiple data formats using a common format (e.g. encoding schemes)

Question 13

Layer 5

Answer 13

• Session Layer
• Establishes, manages, and terminates sessions between two communicating hosts
• synchronizes dialog between the presentation layers of the two hosts and manages their data exchange
• offers efficient data transfer, CoS, and exception reporting of upper layer problems

Question 14

Layer 4

Answer 14

• Transport layer
• TCP/UDP and Port number
• defines services to segment, transfer, and reassemble the data for individual communications between the end devices

Question 15

Layer 3

Answer 15

• Network layer
• Source and Destination IP address
• Routers
• provides connectivity and path selection between two hosts systems that may be located on geographically separated networks
• layer that manages the connectivity of hosts by providing logical addressing

Question 16

Layer 2

Answer 16

• Data-Link layer
• Source and Destination MAC address
• Switches
• defines how data is formatted for transmission and how access to physical media is controlled
• includes error detection and correction to ensure reliable delivery of the data

Question 17

Layer 1

Answer 17

• Physical layer
• physical components of the network (e.g. cables)
• enables bit transmission between end devices
• defines specifications needed for activating, maintaining, and deactivating the physical link between end devices
• Example: voltage levels, physical data rates, maximum transmission distances, physical connectors