Ch 9

Question 1

multiplexing definition

Answer 1

dividing data into smaller segments and interleaving communications across a medium

Question 2

3 properties of reliability

Answer 2

tracking segments
acknowledging delivery
retransmitting unacknowledged segments

Question 3

applications using udp

Answer 3

live audio, live video, VOIP (to avoid delays)
dns (for simple queries)
SNMP or TFTP (application handles reliability)

Question 4

connection oriented definition

Answer 4

establishing virtual connection / session.
amount of data to exchange is negotiated.
communication can be managed

Question 5

flow-control

Answer 5

regulating amount of data that source transmits to prevent retransmissions

Question 6

stateful

Answer 6

tracking what info has been sent and what has been acknowledged.

Question 7

size of TCP overhead

Answer 7

20 bytes

Question 8

port ranges

Answer 8

well known: 0-1023

registered: 1024 - 49151
dynamic: 49152 - 65535

Question 9

20 and 21

Answer 9

FTP

Question 10

22

Answer 10

SSH

Question 11

23

Answer 11

Telnet

Question 12

25

Answer 12

SMTP

Question 13

53

Answer 13

DNS

Question 14

67, 68

Answer 14

DHCP (uses UDP)

Question 15

69

Answer 15

TFTP (uses UDP)

Question 16

80

Answer 16

HTTP

Question 17

110

Answer 17

POPv3

Question 18

143

Answer 18

IMAP (Internet Message Access Protocol)

Question 19

161

Answer 19

SNMP (simple network management protocol) uses UDP

Question 20

443

Answer 20

HTTPS

Question 21

purpose of 3 way handshake

Answer 21

establish that destination is online
verify that service is accepting requests
tells destination that client was to establish session on that port

Question 22

flag values

Answer 22

URG, ACK, PSH, RST (error or timeout), SYN, FIN

Question 23

selective acknowledgments (SACK)

Answer 23

allows destination to acknowledge bytes in discontinuous segments so that only the missing segments need to be retransmitted.