Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

networks > Chapters 1-4 > Flashcards

Chapters 1-4 Flashcards

1
Q

The scripting language invented by Dutch programmer Guido van Rossum

A

Python

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Python has these instead of Arrays

A

Lists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The way to access values at the end of a string

A

Negative indexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a host

A

An end system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a packet switch

A

A device that forwards packets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Communication Links

A

fiber, copper, radio satellite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Network

A

A collection of devices, routers, and links managed by an organization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

This is called a “network of networks”

A

The Internet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Protocols

A

Control sending, receiving of mesages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

RFC

A

Request for Comments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

IETF

A

Internet Engineering Task Force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Network edge

A

clients and servers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Network core

A

interconnected routers, network of networks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Frequency Division Multiplexing(FDM)

A

Different channels transmitted in different frequency bands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Wireless Local Area Networks(WLAN)

A

Provide connection within or around a building

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Wide-area Cellular Access Networks

A

Provide connection from mobile, cellular network operators, typically within 10’s of Kilometers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Bit

A

Propagates between transmitter/receiver pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Physical link

A

What lies between transmitter and receiver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Guided media

A

signals propagate in solid media such as copper, fiber, coax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Unguided media

A

Signals propagate freely, e.g. radio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Twisted pair (TP)

A

Two insulated copper wires

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Packet-switching

A

Hosts break application-layer messages into packets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Length (L)

A

Length of a packet in bits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Transmission rate (R)

A

How fast bits are being transmitted in bits/sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Transmission delay

A

Takes L/R seconds to transmit (push out ) L-bit packet into link at R bps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Store and forward

A

Entire packet must arrive at router before it can be transmitted on next link

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

End-end delay

A

2L/R, assuming zero propagation delay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What happens if arrival rate to link exceeds transmission rate of link for a period of time

A

Packet queuing and loss, packets will queue and wait to be transmitted on output link, some may be dropped if router fills up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Forwarding

A

Local action, move arriving packets from router’s input to appropriate router output link

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Routing

A

Global action, determine source-destination paths taken by packets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Time Division Multiplexing (TDM)

A

Time divided into slots, in which a user can utilize the entire bandwidth for a limited time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How do hosts connect to the internet

A

Internet Service Providers (ISPs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

“Tier-1” commercial ISPs

A

National and international coverage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Content Provider Networks (CPNs)

A

Private network that connects its data centers to Internet, often bypassing tier-1, regional ISPs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What happens when arrival rate to link exceeds output link capacity

A

Packet Loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the four sources of packet delay?

A

Nodal Processing, Queueing, Transmission, and Propagation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Throughput

A

Rate at which bits are being sent from sender to receiver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Instantaneous throughput

A

Rate at given point in time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Average throughput

A

Rate over longer period of time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Bottleneck link

A

Link on end-end path that constrains end-end throughput

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Virus

A

Self-replicating infection by receiving/executing object (e.g., e-mail attachment)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Worm

A

Self-replicating infection by passively receiving object that gets itself executed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Spyware

A

Can record keystrokes, websites visited, upload info to collection site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Denial of Service (DoS)

A

Attackers make resources (server, bandwidth) unavailable to legitimate traffic by overwhelming resource with bogus traffic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Packet sniffing

A

Promiscuous network interface reads/records all packets, including passwords, passing by

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

IP spoofing

A

Send packet with false source address

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Layer 5

A

Application layer, highest in IP stack model, contains supporting network applications such as IMAP, SMTP, HTTP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Layer 4

A

Transport layer, process-process data transfer, TCP, UDP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Layer 3

A

Network layer, routing of datagrams from source to destination, IP and routing protocols

50
Q

Layer 2

A

Link layer, data transfer between neighboring network elements through things like Ethernet, WiFi, or PPP

51
Q

Layer 1

A

Physical layer, bits “on the wire”

52
Q

Arpanet

A

The proto version of the Internet developed by DARPA back in the 60’s

53
Q

ISO/OSI reference model

A

A model similar to the IP stack, but contains the two extra layers of presentation and session

54
Q

Wireshark

A

A type of packet sniffer

55
Q

Socket

A

analogous to a door, data is shoved through the socket from the application layer to the transport layer

56
Q

Identifier

A

A part of a process which includes both the IP address and port number associated with process on host

57
Q

Data integrity

A

Ensures that the data sent is received unchanged, some apps require 100%, other can tolerate some loss

58
Q

TCP service

A

A reliable protocol which won’t overwhelm the receiver and maintains integrity, but will go slower

59
Q

UDP

A

An unreliable data transfer protocol which doesn’t provide security congestion control or other features, but does go much faster than TCP

60
Q

Transport Layer Security (TLS)

A

provides encrypted TCP connections, ensures data integrity

61
Q

hypertext transfer protocol (HTTP)

A

Web’s application layer protocol, a client sends a request and the server sends a response

62
Q

HTTP uses this type of socket

A

TCP

63
Q

Non-persistent HTTP

A
  1. TCP connection opened
  2. At most one object sent over TCP connection
  3. TCP connection closed
    Downloading multiple objects required multiple connections
64
Q

Persistent HTTP

A
  1. TCP connection opened to a server
  2. Multiple objects can be sent over single TCP
    connection between client, and that server
  3. TCP connection closed
65
Q

Round Trip Time (RTT)

A

Time for a small packet to travel from client to server and back

66
Q

200

A

OK

67
Q

301

A

Moved Permanently

68
Q

400

A

Bad Request

69
Q

404

A

Not Found

70
Q

505

A

HTTP Version Not Supported

71
Q

Cookie

A

Used to maintain some state between transactions

72
Q

Web cache

A

A copy of an object from another client which is being served to a client by a server

73
Q

Simple Mail Transfer Protocol (SMTP)

A

A protocol used by mail servers to send, receive, and relay outgoing email between senders and receivers

74
Q

Internet Mail Access Protocol (IMAP)

A

Provides retrieval, deletion, folders of stored messages on server

75
Q

Domain Name System (DNS)

A

Distributed database implemented in hierarchy of many name servers. provides hostnames and aliases among other things. Is decentralizeed

76
Q

Hierarchy of DNS

A

Root, highest
Top Level Domain, middle
Authoritative, lowest

77
Q

Root name servers

A

Contact-of-last-resort by name servers that can not resolve name, incredibly important to internet function. 13 logical root name “servers” worldwide

78
Q

ICANN (Internet Corporation for Assigned Names and Numbers)

A

Manages root DNS domain

79
Q

Top-Level Domain (TLD) servers

A

Responsible for .com, .org, .net and others, along with top-level country domains such as .cn, .uk, .fr

80
Q

Authoritative DNS servers

A

Organization’s own DNS servers, providing authoritative hostname to IP mappings for organization’s named hosts

81
Q

Local DNS name servers

A

Does not strictly belong to hierarchy, each ISP has one, when host makes DNS query, query is sent to its local DNS server

82
Q

Peer-to-peer (P2P) architecture

A

No always-on server, arbitrary end systems directly communicate as peers who request and send files to each other

83
Q

Tracker

A

A server within P2P, while there is not supposed to be an always-on server, there has to be this to let peers find each other

84
Q

CBR (constant bit rate)

A

Video encoding rate fixed

85
Q

VBR (variable bit rate)

A

Video encoding rate changes as amount of spatial, temporal coding changes

86
Q

Streaming

A

Video is being sent played and deleted as user is watching

87
Q

Apache

A

A commonly used HTTP server

88
Q

Multiplexing

A

Multiple datagrams are combined into one in order to send more efficiently through sockets

89
Q

Demultiplexing

A

Splitting up multiplexed datagrams and distributing each datagram to the proper host system

90
Q

Checksum

A

The sum of bits in a message which is appended to the end, meant to ensure integrity

91
Q

ACK

A

Receiver explicitly tells sender that pkt received OK

92
Q

NAK

A

Receiver explicitly tells sender that pkt had errors

93
Q

Time-to-live (TTL)

A

In UDP connections is a limit to how many times a packet can hop inside a network before being discarded by a router

94
Q

Timeout

A

The amount of time a round trip can take before being reported as lost and requesting a copy from the sender

95
Q

Flow control

A

Mitigates one sender sending data too fast for one receiver

96
Q

Handshake

A

A client and server introduce each other and identify themselves, establishing a connection that data can be sent through

97
Q

Congestion control

A

Mitigates too many senders sending data too fast

98
Q

QUIC (Quick UDP Internet Connections)

A

An encrypted transport layer protocol designed by google, meant to get the positives of UDP and TCP without the downsides of either

99
Q

Data plane

A

Local, per-router function, determines how datagram arriving on input port is forwarded to output port

100
Q

Control plane

A

Network-wide logic, determines how datagram is routed among routers along end-end path from source host to destination host

101
Q

Software-Defined Networking (SDN)

A

Remote controller computes, installs forwarding tables in router on the control plane

102
Q

Per-router control plane

A

Individual routing algorithm components in each and every router interact in the control plane

103
Q

Routing table

A

A data table stored in a router that lists the routes to particular network destinations, can be user defined, or software defined

104
Q

Longest prefix match

A

When looking for forwarding table entry for given destination address, use longest address prefix that matches destination address

105
Q

Multistage switch

A

(n)x(n) switch from multiple stages of smaller switches

106
Q

Head-of-the-line (HOL) blocking

A

Queued datagram at front of queue prevents others in queue from moving forward

107
Q

Buffering

A

Required when datagrams arrive from fabric faster than link transmission rate

108
Q

Drop policy

A

Defines which datagrams to drop if no free buffers

109
Q

Scheduling discipline

A

Chooses among queued datagrams for transmission

110
Q

Packet scheduling

A

Deciding which packet to send next on link

111
Q

IPv4 address

A

32-bit identifier associated with each host or router interface

112
Q

IPv6 address

A

128-bit identifier associated with each host or router interface

113
Q

Interface

A

Connection between host/router and physical link

114
Q

Subnet

A

Device interfaces that can physically reach each other without passing through an intervening router

115
Q

CIDR (Classless InterDomain Routing)

A

Standard that tells how many digits of an IP address are fixed and which can be changed within a subnet

116
Q

Subnet mask

A

A standard which tells how many characters in each byte of an IP address can be changed

117
Q

DHCP (Dynamic Host Configuration Protocol)

A

Dynamically get IP address from server

118
Q

NAT (Network Address Translation)

A

All devices in local network share just one IPv4 address as far as outside world is concerned, but NAT server routes them to the correct end system, meant to save on IPv4 addresses which have run out

119
Q

Tunneling

A

IPv6 datagrams are given an IPv4 header in order to be cleanly sent over to the destination port

120
Q

The internet’s “thin waist”

A

IP, the only network layer protocol

121
Q

Middleboxes

A

Network layer protocols which used to exist before IP was standardized as the one network layer protocol to be used

networks (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions