Isa 301 Exam 2

Front 1

Transport layer (3 functions)

Back 1

Linking application layer to network, segmenting, session management mad a

Front 2

Network layer (2 functions)

Back 2

IP (layer 3) - routing (encapsulation), and addressing

Front 3

Encapsulation

Back 3

Performed at the sending end - adding more and more layer to the original message and then at the receiving end peel off those layers to get back to the original message

Front 4

Transmission Control Protocol (TCP)

Back 4

Links application layer to network layer - breaks down long data into smaller PDUs

Front 5

Internet protocol (IP)

Back 5

Network layer protocol - addressing and routing (routes message to final destination)

Front 6

User datagram protocol (UDP)

Back 6

Used when the sender needs to send a single small packet to the receiver

Front 7

IP version 4 (IPv4)

Back 7

192 bit header - 192.168.1.5

Front 8

IP version 6 (IPv6)

Back 8

320 bit header (40 bytes) - 192.168.20.4.3.15

Front 9

Source port address

Back 9

Generated a message the application layer tells the transport layer it's own port address

Front 10

Destination port address

Back 10

Tells the port address at the destination computer

Front 11

Segmenting

Back 11

Taking the outgoing message and breaking it down and then repackaging the message at the receiver end

Front 12

Application layer address

Back 12

Computer does not directly use this - the computer has to route out the Internet address (ex: www.miamioh.edu)

Front 13

Network layer address

Back 13

Transports the application address into an IPv4 - 4 bytes long

Front 14

Data link layer address

Back 14

Translated from IP into an Ethernet address - 6 bytes long; hexicdecimal - 6 groups of 4 bits ; usually permanently encoded in each network card

Front 15

Subnets

Back 15

Addressing hierarchy to make IP address assignment more functional (1st part defines network - 2nd part defines the particular computer or host on the network)

Front 16

Dynamic host configuration protocol (DHCP)

Back 16

Software packaging - lease an address to the computer

Front 17

Address resolution

Back 17

Process of translating the application layer address of the destination into a network layer address and in turn translating that into a data link layer address

Front 18

Server name resolution*

Back 18

The translation of application layer address into network layer address

Front 19

Name servers

Back 19

A series of computers that proved DNS services - essentially a database of all IP addresses with their internet addresses

Front 20

domain name service (DNS) servers

Back 20

Used to do the server name resolution - managed by networks - sending DNS servers to get the URL back so that the application layer can get there

Front 21

Routing

Back 21

The process of deterring the route or path through the network that a message will travel from the sending computer to the receiving computer

Front 22

Routers

Back 22

Usually found at the edge of subnets because they are the devices that connect subnets together and enable messages to flow from one subnet to another as messages nice through the network from sender to receiver (responsible for sending stuff over the Internet)

Front 23

Broadcasting

Back 23

Sends a broadcast message to all clients asking for whose IP address it is and then request the physical address

Front 24

Routing table

Back 24

Specifies how messages will travel through the network (used to desire where to send the messages it receives) - each router had it's own

Front 25

Centralized routing

Back 25

All routing decisions are made by one central computer or router (commonly used in host-based networks)

Front 26

static routing (decentralized)

Back 26

All computes or routers in the network make their own routing decisions following formal routing protocol (network manager says this is the route)

Front 27

Dynamic routing (adaptive routing)

Back 27

Routing decisions are made in a decentralized manner by individual computers (depending on moment in time the router decides what should be next)

Front 28

Link state dynamic routing

Back 28

Computers or routers track the number of hops in the route

Front 29

Multicasting **

Back 29

Most common type of message in the network - transmission between two com others

Front 30

Broadcast v multicast**

Back 30

Multicast can be anyone and broadcast is just within the subnet

Front 31

Functions of a router

Back 31

determines a path for a packet to travel over, transmits the packet across the path, supports communication between a wide variety of devices and protocols

Front 32

LAN (what & characteristics)

Back 32

Network within a short range - confined space, much faster than WANs, not regulated

Front 33

Information sharing**

Back 33

Having users access the same data files, exchange information via email - improved decision making

Front 34

Resource sharing **

Back 34

One computer sharing hardware device or software package with other computers on the network - dedicated servers

Front 35

Server farms

Back 35

Servers organized into a larger set of servers on one part of a network

Front 36

File servers

Back 36

Allow many users to share the same set of files on a common shared disk drive

Front 37

Print server

Back 37

Handle print requests on the LAN

Front 38

Peer-to-peer networks

Back 38

Relatively uncommon - do not require a dedicated server - all computers run network software that allows them to run as both a client and a server

Front 39

Network operating systems (NOS)

Back 39

Software that controls the network - 1 that runs on the network server; 2 that runs on the network client

Front 40

Topology

Back 40

Basic geometric layout of the network - the way in which the computers on the network are interconnected

Front 41

Logical topology

Back 41

How the network works conceptually

Front 42

Physical topology

Back 42

How the network is physically installed

Front 43

Switch

Back 43

Intelligent device with a small computer built in that is designed to manage a separate set of point-to-point circuits

Front 44

forwarding table

Back 44

similar to routing tables - lists the Ethernet address of the computer connected to each port on the switch

Front 45

cut-through switching

Back 45

switch begins to transmit the incoming packet on the proper outgoing circuit as soon as it is read the destination address in the frame (begins transmitting before it has received the ful frame)

Front 46

store and forward switching

Back 46

the switch does not begin transmitting the outgoing frame until it has received the entire incoming frame - discards frame if errors are found

Front 47

fragment-free switching

Back 47

-lies between the extremes of cut-through and store and forward
- first 64-bytes are read and stores - read header data and presume error free

Front 48

carrier sense multiple access with collision detection (CSMA/CD)

Back 48

contention-based MAC technique - wait until the circuit is free and then transmit

Front 49

Collision detection (CD)

Back 49

listen while transmitting - does not eliminate collisions - reduced them to mange-able proportions

Front 50

100Base-T (type of Ethernet)

Back 50

most common form of Ethernet today
100 Mbps

Front 51

Types of Ethernet

Back 51

10Base-T, 100Base-T, 1000Base-T & 1000Base-F, 10BgE, 40GbE, 10/100/1000 Ethernet

t - unshielded twisted pair
base - baseband

Front 52

10/100/1000 Ethernet

Back 52

hybrid Ethernet type that can run at any of these three speeds
- NICs and switches detect the signal transmitted by the computer or device on the other end of the cable and will use 10, 100, or 1 Gbps depending on the other device
- switches usually operate at the lowest speed that everyone else is operating at

Front 53

Wireless Ethernet

Back 53

commercially named for a set of standards developed by IEEE 802.11 x

Front 54

IEEE 802.11 x - what does the x mean**

Back 54

- 802.11n is the dominant standard and the newest standard
- operates at 2 frequencies -- 2.4GHz and 5GHz

Front 55

physical star

Back 55

central AP all computers direct the transmissions

Front 56

logical bus

Back 56

radio frequencies that are shared

Front 57

workgroup switch

Back 57

the hub of an Ethernet is replaced by a switch - support small set of computers

Front 58

forwarding table

Back 58

lists Ethernet address of the computer connected to each port
- switch first turned on forwarding table is empty
- learns address to build table

Front 59

layer-2 switch

Back 59

the switches use Ethernet address to decide which port (Ethernet is a data link layer or layer-2 protocol)

Front 60

latency**

Back 60

the time it takes a device from receiving a frame to transmitting it

Front 61

Wi-Fi Protected Access (WPA)

Back 61

-every frame is encrypted using a key and the key can be fixed in the AP or it can be dynamic - longer than WEP key so harder to break

Front 62

Wireless Equivalent Privacy (WEP)

Back 62

AP requires the user to have a key in order to communicate with it

Front 63

network server

Back 63

server lacks sufficient capacity to process all the requests it receives in a timely manner

Front 64

network circuit

Back 64

(connecting LAN to the corporate BN) - circuit lacks enough capacity to transmit all the requests to the server

Front 65

Backbone Network (BN)

Back 65

high-speed network that connects to many networks

Front 66

campus network

Back 66

BN that connects many BNs spanning several nearby buildings for a single organization

Front 67

enterprise network

Back 67

backbone network that connects all networks within a company - regardless of whether is crosses state, national, or international boundaries

Front 68

Little table - important**

Back 68

Front 69

layer-3 switches

Back 69

function the same way as layer-2 switches but they switch messages on the basis of their network layer address (more capable in processing faster)

Front 70

backbone architecture

Back 70

the way in which the backbone interconnects the networks attached to it and how it manages the way in which packets from one network move through the backbone to other networks

Front 71

routed backbones

Back 71

routers that move packets on the basis of the network layer addresses

Front 72

switched backbones

Back 72

switches that move packets based on data link layer addresses
- use a star topology with one switch at its center
most common type of BN used in the distribution layer

Front 73

virtual LANs

Back 73

switches that move packets through LANs that are built virtually

Front 74

access layer

Back 74

layer closest to the user

Front 75

distribution layer

Back 75

connects the LANs together - contains the TCP/IP gateways

Front 76

core layer

Back 76

part of the backbone that connects to the diferent BNs together

Front 77

Main distribution facility (MDF)**
(& rack)

Back 77

Central distribution facility (CDF) = room containing the rack of equipment
rack - all network devices for one part of the building are located in the same room

Front 78

patch cables

Back 78

the devices int he rack are connect among themselves using these very short cables

Front 79

chassis switch

Back 79

used instead of a rack - enables users to plug modules directly into the switch

Front 80

modules

Back 80

each module is a certain type of network device

Front 81

Virtual LAN (VLAN)

Back 81

new type of LAN-BN architecture made possible by intelligent high-speed switches
- assigned to LAN segments by software rather than hardware
- faster and less traffic
- wayy more complex

Front 82

LAN**

Back 82

broadcast messages always being sent - everyone on the subnet gets the message (adds A LOT to network traffic)

Front 83

single switch VLAN

Back 83

the computers in the same VLAN act as though they are connected to the same physical switch or hub in a certain subnet
- individual switches disappear - all switches done inside through software

Front 84

IEEE 802.1q standard

Back 84

VLAN standard - signifies that it's a vLAN network - tag information

Front 85

VLAN tag

Back 85

option - only used when using a VLAN
- 4 bytes
1st 2 bytes 81 00 - equipment and software immediately knows this is a VLAN
- 2nd 2 bytes - quality of service allows for prioritization

Front 86

multiswitch VLAN

Back 86

more common
- people put in various locations together and pretend they are in the same location
- switches all part of the same subnet (IP address) - all conencted to the same router
- more common than a single switch

Front 87

Wide Area Networks (WANs)

Back 87

long distances connecting different offices in different cities or countries

Front 88

Local exchange carrier (LEC)

Back 88

provides local telephone services

Front 89

Interexchange carrier (IXC)

Back 89

long distance services

Front 90

publish switches telephone network (PSTN)

Back 90

telephone networks operated by the common carriers

Front 91

Plain old telephone services (POTS)

Back 91

dial up services that households probably used at one time
- lease lines to use circuit effectively

Front 92

integrated services digital network (ISDN)

Back 92

combines (convergence) voice, video, and data over the same digital circuit
- acceptance has been slow

Front 93

basic rate interface (BRI)

Back 93

provides communication circuit with two 64-Kbps (voice channel) digital transmission channels (B & D channels)

Front 94

primary rate interface (PRI)

Back 94

same capacity as a T1 circuit (1.544 Mbps)

Front 95

ring architecture

Back 95

connects all computers in a closed loop with each computer linked to the next

Front 96

star architecture

Back 96

connects all computers to one central computer that routes messages to the appropriate computer

Front 97

full mesh

Back 97

every computer is connected to every other computer

Front 98

partial mesh

Back 98

many but not all of the computers are connected
- solution to full mess - more practical
- used most commonly by WANs
- short routes and many possible routes

Front 99

T1 circuit**

Back 99

- can be used to transmit data but often are used to transmit both voice and data
- data rate of 1.544 Mbps - absolute standard
- voice channel basic building blocks of telecommunication industry

Front 100

synchronous optical network (SONET)

Back 100

- american standard for high-speed dedicated-circuit services
- transmission speeds begin at OC-1 level (optical carrier level 1) of 51.84 Mbps - slowest optic fiver

Front 101

packet assembly/disassembly device (PAD)

Back 101

user's connection into the network - can be owned and operated by the customer of the by CC
- converts the senders data into the network layer and data link layer packets used by the packet network and sends them through the packet switched network

Front 102

datagram

Back 102

connectionless service
- adds destination address and sequence number to each packet and info about the data stream to which the packet belongs

Front 103

virtual circuit

Back 103

- more common routing method
- all packets for a transmission take the same route over the virtual circuit that has been set up for that particular transmission

Front 104

permanent virtual circuits (PVCs)

Back 104

defines for frequent and consistent use by the network (do not change unless network manager changes the network)

Front 105

point of presence (POP)

Back 105

location at which the packet-switched network connects to the local telephone exchange

Front 106

Asynchronous transfer mode (ATM)

Back 106

similar to Ethernet and TCP/IP
- uses different layer-2 and layer-3 protocols
- encapsulation
- no error control

Front 107

frame relay

Back 107

- poor man's ATM
- one of the most commonly used WAN services in the world
- no error control - checks for errors and discards packets with errors
- no QoS

Front 108

Ethernet services

Back 108

all traffic entering the packet network must be Ethernet using IP

Front 109

multi-protocol label switching (MPLS)

Back 109

designed to work with a variety of commonly used layer-2 potocols

Front 110

internet service provide (ISP)

Back 110

common carrier for the circuit and the ISP for internet access

Front 111

VPN gateway

Back 111

specially designed router or switch - provide access from your networks to the VPN

Front 112

VPN software

Back 112

commonly used on home computers or laptops to provide the same secure tunnels to people working from off site

Front 113

layer-2 VPN

Back 113

layer-2 packet to select the VPN tunnel and encapsulates the entire packet

Front 114

layer-3 VPN

Back 114

layer-3 packet to select VPN tunnel and encapsulates the entire packet - discards incoming layer-2 packet and generates an entirely new layer-2 packet at the destination

Front 115

Intranet VPN

Back 115

provides virtual circuits between organization offices over the internet

Front 116

extranet VPN

Back 116

same as intranet but connect several different organizations

Front 117

access VPN

Back 117

enables employees to access the organization's networks from remote locations