CS6250 COMPUTER NETWORK EXAM 2 2026/2027
Questions and answers | Correct answers highlighted in green
1.
Network Layer. CORRECT ANSWER:
logical communication between hosts
2.
Transport Layer. CORRECT ANSWER:
logical communication between processes
3.
relies on, enhances, network layer services
4.
Transport Layer Actions: Sender. CORRECT ANSWER:
§ is passed an application-
layer message
§ determines segment header fields values
§ creates segment
§ passes segment to IP
5.
Transport Layer Actions: Receiver. CORRECT ANSWER:
§ receives segment from IP
§ checks header values
§ extracts application-layer message
§ demultiplexes message up to application via socket
6.
TCP: Transmission Control Protocol. CORRECT ANSWER:
• reliable, in-order delivery
7.
congestion control
8.
flow control
9.
connection setup
10.
UDP: User Datagram Protocol. CORRECT ANSWER:
• unreliable, unordered delivery
11.
no-frills extension of "best-effort" IP
§ "no frills," "bare bones" Internet transport protocol
§ "best effort" service, UDP segments may be:
EXAM REVIEW MATERIAL Page 1
, 12.
lost
13.
delivered out-of-order to app
§ connectionless:
14.
no handshaking between UDP sender, receiver
15.
each UDP segment handled independently of others
16.
Multiplexing/demultiplexing. CORRECT ANSWER:
17.
How demultiplexing works. CORRECT ANSWER:
18.
Connectionless demultiplexing. CORRECT ANSWER:
19.
Connectionless demultiplexing: example. CORRECT ANSWER:
20.
Connection-oriented demultiplexing. CORRECT ANSWER:
§ TCP socket identified by
4-tuple:
21.
source IP address
22.
source port number
23.
dest IP address
24.
dest port number
§ server may support many simultaneous TCP sockets:
25.
each socket identified by its own 4-tuple
26.
each socket associated with a different connecting client
§ demux: receiver uses all four values (4-tuple) to direct segment to appropriate socket
EXAM REVIEW MATERIAL Page 2
Questions and answers | Correct answers highlighted in green
1.
Network Layer. CORRECT ANSWER:
logical communication between hosts
2.
Transport Layer. CORRECT ANSWER:
logical communication between processes
3.
relies on, enhances, network layer services
4.
Transport Layer Actions: Sender. CORRECT ANSWER:
§ is passed an application-
layer message
§ determines segment header fields values
§ creates segment
§ passes segment to IP
5.
Transport Layer Actions: Receiver. CORRECT ANSWER:
§ receives segment from IP
§ checks header values
§ extracts application-layer message
§ demultiplexes message up to application via socket
6.
TCP: Transmission Control Protocol. CORRECT ANSWER:
• reliable, in-order delivery
7.
congestion control
8.
flow control
9.
connection setup
10.
UDP: User Datagram Protocol. CORRECT ANSWER:
• unreliable, unordered delivery
11.
no-frills extension of "best-effort" IP
§ "no frills," "bare bones" Internet transport protocol
§ "best effort" service, UDP segments may be:
EXAM REVIEW MATERIAL Page 1
, 12.
lost
13.
delivered out-of-order to app
§ connectionless:
14.
no handshaking between UDP sender, receiver
15.
each UDP segment handled independently of others
16.
Multiplexing/demultiplexing. CORRECT ANSWER:
17.
How demultiplexing works. CORRECT ANSWER:
18.
Connectionless demultiplexing. CORRECT ANSWER:
19.
Connectionless demultiplexing: example. CORRECT ANSWER:
20.
Connection-oriented demultiplexing. CORRECT ANSWER:
§ TCP socket identified by
4-tuple:
21.
source IP address
22.
source port number
23.
dest IP address
24.
dest port number
§ server may support many simultaneous TCP sockets:
25.
each socket identified by its own 4-tuple
26.
each socket associated with a different connecting client
§ demux: receiver uses all four values (4-tuple) to direct segment to appropriate socket
EXAM REVIEW MATERIAL Page 2
