1. Which layer is responsible for establishing a temporary communication session between the source and destination host applications?
- A. Application layer
- B. Data link layer
- C. Network layer
- D. Physical layer
- D. Transport layer
2. Which three are transport layer responsibilities? (Choose three.)
- A. Conversation multiplexing
- B. Identifying frames
- C. Identifying routing information
- D. Segmenting data and reassembling segments
- E. Tracking individual conversations
3. Which transport layer protocol statement is true?
- A. TCP has fewer fields than UDP.
- B. TCP is faster than UDP.
- C. UDP is a best-effort delivery protocol.
- D. UDP provides reliability.
4. Which transport layer protocol would be used for VoIP applications?
- A. Session Information Protocol (SIP)
- B. Transmission Control Protocol (TCP)
- C. User Datagram Protocol (UDP)
- D. VoIP Transfer Protocol
5. Which transport layer protocol ensures reliable same-order delivery?
- A. ICMP
- B. IP
- C. TCP
- D. UDP
6. Which TCP header statement is true?
- A. It consists of 4 fields in an 8-byte header.
- B. It consists of 8 fields in a 10-byte header.
- C. It consists of 10 fields in a 20-byte header.
- D. It consists of 20 fields in a 40-byte header.
7. Which two applications would use the TCP transport layer protocol? (Choose two.)
- A. FTP
- B. HTTP
- C. ICMP
- D. TFTP
- E. VoIP
8. Which of the following is a stateless best-effort delivery transport layer protocol?
- A. ICMP
- B. IP
- C. TCP
- D. UDP
9. Which UDP header statement is true?
- A. It consists of 4 fields in an 8-byte header.
- B. It consists of 8 fields in a 10-byte header.
- C. It consists of 10 fields in a 20-byte header.
- D. It consists of 20 fields in a 40-byte header.
10. Which two applications would use the UDP transport layer protocol? (Choose two.)
- A. FTP
- B. HTTP
- C. ICMP
- D. TFTP
- E. VoIP
11. Which two fields are the same in a TCP and UDP header? (Choose two.)
- A. Control bits
- B. Destination port number
- C. Sequence number
- D. Source port number
- E. Well-known port number
12. Assume a host with IP address 10.1.1.10 wants to request web services from a server at 10.1.1.254. Which of the following would display the correct socket pair?
- A. 1099:10.1.1.10, 80:10.1.1.254
- B. 10.1.1.10:80, 10.1.1.254:1099
- C. 10.1.1.10:1099, 10.1.1.254:80
- D. 80:10.1.1.10, 1099:10.1.1.254
13. Which port group includes port numbers for FTP, HTTP, and TFTP applications?
- A. Dynamic ports
- B. Private ports
- C. Registered ports
- D. Well-known ports
14. Which Windows command would display the protocols in use, the local address and port numbers, the foreign address and port numbers, and the connection state?
- A. ipconfig /all
- B. Ping
- C. Netstat
- D. Traceroute
15. Which of the following would be valid source and destination ports for a host connecting to an email server?
- A. Source: 25, Destination: 49152
- B. Source: 80, Destination: 49152
- C. Source: 49152, Destination: 25
- D. Source: 49152, Destination: 80
16. Which control bit flags are used during the three-way handshake?
- A. ACK and FIN
- B. FIN and RESET
- C. RESET and SYN
- D. SYN and ACK
17. How many exchanges are needed to end both sessions between two hosts?
- A. One exchange
- B. Two exchanges
- C. Three exchanges
- D. Four exchanges
- E. Five exchanges
18. What field is used by the destination host to reassemble segments into the original order?
- A. Control Bits
- B. Destination Port
- C. Sequence Number
- D. Source Port
- E. Window Size
19. What field is used to provide flow control?
- A. Control Bits
- B. Destination Port
- C. Sequence Number
- D. Source Port
- E. Window Size
20. What happens when a sending host senses there is congestion?
- A. The receiving host increases the number of bytes it sends before receiving an acknowledgment from the sending host.
- B. The receiving host reduces the number of bytes it sends before receiving an acknowledgment from the sending host.
- C. The sending host increases the number of bytes it sends before receiving an acknowledgment from the destination host.
- D. The sending host reduces the number of bytes it sends before receiving an acknowledgment from the destination host.
21. Why is UDP desirable for protocols that make a simple request and reply transactions?
- A. Flow Control
- B. Low overhead
- C. Reliability
- D. Same-order delivery
22. Which UDP datagram reassembly statement is true?
- A. UDP does not reassemble the data.
- B. UDP reassembles the data in the order that it was received.
- C. UDP reassembles the data using control bits.
- D. UDP reassembles the data using sequence numbers.
23. Which of the following would be valid source and destination ports for a host connecting to a DNS server?
- A. Source: 53, Destination: 49152
- B. Source: 1812, Destination: 49152
- C. Source: 49152, Destination: 53
- D. Source: 49152, Destination: 1812
24. Which transport layer feature is used to establish a connection-oriented session?
- A. UDP sequence number
- B. TCP port number
- C. TCP 3-way handshake
- D. UDP ACK flag
TCP uses the 3-way handshake. UDP does not use this feature. The 3-way handshake ensures there is connectivity between the source and destination devices before transmission occurs.
25. What is the complete range of TCP and UDP well-known ports?
- A. 0 to 255
- B. 256 - 1023
- C. 1024 - 49151
- D. 0 to 1023
There are three ranges of TCP and UDP ports. The well-know range of port numbers is from 0 – 1023.
26. What is a socket?
- A. The combination of a source IP address and port number or a destination IP address and port number
- B. The combination of the source and destination sequence and acknowledgment numbers
- C. The combination of the source and destination IP address and source and destination Ethernet address
- D. The combination of the source and destination sequence numbers and port numbers
A socket is a combination of the source IP address and source port or the destination IP address and the destination port number.
27. How does a networked server manage requests from multiple clients for different services?
- A. The server sends all requests through a default gateway.
- B. The server uses IP addresses to identify different services.
- C. Each request has a combination of source and destination port numbers, coming from a unique IP address.
- D. Each request is tracked through the physical address of the client.
Each service provided by a server, such as email or file transfers, uses a specific port number. The source port number of a service request identifies the client that is requesting services. The destination port number identifies the specific service. Servers do not use address information to provide services. Routers and switches use addressing information to move traffic through the network.
28. What happens if part of an FTP message is not delivered to the destination?
- A. The FTP source host sends a query to the destination host.
- B. The part of the FTP message that was lost is re-sent.
- C. The message is lost because FTP does not use a reliable delivery method.
- D. The entire FTP message is re-sent.
Because FTP uses TCP as its transport layer protocol, sequence and acknowledgment numbers will identify the missing segments, which will be re-sent to complete the message.
29. What type of applications are best suited for using UDP?
- A. Applications that require retransmission of lost segments
- B. Applications that are sensitive to packet loss
- C. Applications that are sensitive to delay
- D. Applications that need reliable delivery
UDP is not a connection-oriented protocol and does not provide retransmission, sequencing, or flow control mechanisms. It provides basic transport layer functions with a much lower overhead than TCP. Lower overhead makes UDP suitable for applications which are sensitive to delay.