BOOK REVIEW IN COMMUNICATIONS
CHAPTER 23
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Electronic Communications System By Wayne Tomasi
DATA-LINK PROTOCOLS AND DATA
COMMUNICATIONS NETWORKS
DEFINITIONS
1)
The primary goal of __________ is to give
users of a network the tools necessary for
setting up the network and performing
data flow control.
2)
A set of rules implementing and governing
an orderly exchange of data between
two layer devices.
3)
The transmitting station in a data link
protocol.
4)
The receiving station in a data link
protocol.
5)
Data link network wherein all stations have
equal access to the network.
6)
Discipline, Flow Control and Error Control.
7)
Coordinates hop-to-hop data delivery
where a hop may be a computer, a
network controller, or some type of
network-connecting device
8)
9)
Determines which device is transmitting
and which is receiving at any point in
time.
Coordinates the rate which data are
transported over a link and generally
provides an acknowledgement
mechanism.
Prepared By : MARY JANE R. ROGELIO
TERMS
Network Architecture
Data-Link Protocol
Master Station
Slave Station
Peer-to Peer Network
Functions of Data-link Protocol
Line Discipline
Line Discipline
Flow Control
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Electronic Communications System By Wayne Tomasi
10)
Specifies means of detecting and
correcting transmission errors.
11)
Two fundamental ways that line discipline
is accomplished in a data
communications network.
12)
It determines which device on the
network can initiate a transmission and
whether the intended receiver is available
and ready to receive a message.
ENQ/ACK
13)
The initiating station begins a session by
transmitting a frame, block, or packet of
data called _________, which identifies the
receiving station.
Enquiry(ENQ)
14)
The response of the destination station
when it is ready to receive.
Positive Acknowledgement (ACK)
15)
The response of the destination station
when it is not ready to receive.
Negative Acknowledgement (NAK)
16)
The best application of the poll/select line
discipline.
Centrally Controlled Data Network
17)
A solicitation sent from the primary to a
secondary to determine if the
secondary has data to transmit
21)
A set of procedures that tells the
transmitting station how much data it can
send before it must stop transmitting and
wait for an acknowledgment from the
destination station
Prepared By : MARY JANE R. ROGELIO
Error Control
Enquiry/Acknowledgement(ENQ/ACK)
and Poll/Select
Poll
Flow Control
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BOOK REVIEW IN COMMUNICATIONS
Electronic Communications System By Wayne Tomasi
22)
The transmitting station sends one
message frame and then waits for an
acknowledgement before sending the
next message frame.
Stop-and Wait Flow Control
23)
A source station can transmit several
frames in succession before receiving an
acknowledgement.
Sliding Window Flow Control
24)
It refers to imaginary receptacles at the
source and destination stations with the
capacity of holding several frames of
data.
Sliding Window
25)
Primary advantage of sliding window
control.
26)
Primary disadvantages of sliding window
flow control.
Complexity and Hardware Capacity
27)
Interpret a frame of data as a group of
successive bits combined into predefined
patterns of fixed length, usually eight bits
each.
Character Oriented Protocols
28)
Another name for character oriented
protocols.
29)
A discipline for serial by bit information
transfer over a data communications
channel.
Bit Oriented Protocol
30)
A character-oriented protocols generally
used on two point networks using
asynchronous data and asynchronous
modems.
Asynchronous Data link Protocols
Prepared By : MARY JANE R. ROGELIO
Network Utilization
Byte-oriented Protocols
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Electronic Communications System By Wayne Tomasi
31)
Developed the first file transfer protocol
designed to facilitate transferring data
between two personal computers in 1979.
Ward Christiansen
32)
Cristiansen's protocol which is relatively
simple data link protocol intended for lowspeed applications.
XMODEM
33)
Remote stations can have more than one
PC or printer.
Synchronous Data-Link Protocols
34)
A group of computers, printers, and other
digital devices.
Cluster
35)
A synchronous character-oriented data
link protocol developed by IBM.
36)
Another name for BSC.
Binary Synchronous Communications
(BSC)
Bisync
37)
Another name for enquiry (ENQ)
character.
38)
The __________ uses longitudinal
redundancy checking (LRC) with ASCIIcoded messages and cyclic redundancy
checking.
Block Check Character (BCC)
39)
A synchronous bit oriented protocol
developed in the 1970's by IBM for use in
system network architecture environment.
Synchronous Data-Link Control (SDLC)
40)
41)
Three transmission states.
Flag Fields, Address Field, Control Field,
Information and Frame Check Sequence
Field are __________.
Prepared By : MARY JANE R. ROGELIO
Format or line turn around
Transient, Idle and Active
SDLC Frame Fields
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42)
43)
It is used for the delimiting sequence for
the frame and to achieve frame and
character synchronization.
It is used for polling, confirming previously
received frames, and several other data
link management functions
Electronic Communications System By Wayne Tomasi
Flags
Control Field
44)
Three frame formats with SDLC.
Information, Supervisory and
Unnumbered
45)
A command or a response that is used to
send unnumbered information.
Unnumbered Information (UI)
46)
A command that places a secondary
station into the initialization mode.
Set Initialization Mode
47)
A response sent by a secondary station to
request the primary to send a SIM
command.
Request Initialization Mode (RIM)
48)
A command that places a secondary into
the normal response mode.
Set Normal Response Mode (SNRM)
49)
A response transmitted from a secondary
station if the primary attempts to send
numbered information frames to it when
the secondary is in the normal disconnect
mode.
50)
A response sent by a secondary when it
wants the primary to place it in the
disconnect mode.
52)
An affirmative response that indicates
compliance to SIM, SNRM or DISC
commands
53)
An exchange of frames between the
primary station and a secondary station.
Prepared By : MARY JANE R. ROGELIO
Disconnect Mode (DM)
Request Disconnect (RD)
Unnumbered Acknowledgement
TEST
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BOOK REVIEW IN COMMUNICATIONS
54)
A flag followed by eight consecutive logic
0's.
55)
A SDLC subcommand causes all
previously set functions to be cleared by
the secondary.
56)
A SLDC subcommand causes the
secondary receiving it to turn on or turn
off its carrier.
57)
58)
A SDLC command causes the addressed
secondary station to pace itself into the
monitor mode.
A SDLC command causes a secondary
station to loop its transmission directly to its
receiver input.
Electronic Communications System By Wayne Tomasi
Turnaround Sequence
Clear
Beacon Test
Monitor Mode
Wrap
A SDLC command causes the
59)
addressed secondary to initiate a series of
internal diagnostic tests.
Self-Test
60)
The transparency mechanism used with
SDLC.
Zero Bit Insertion or Zero Stuffing
61)
It is used prematurely terminate an SDLC
frame.
Message Abort
62)
The encoding scheme used in SDLC.
63)
Standard that defines the frame structure,
delimiting
sequence,
transparency
mechanism and error detection method
used with HDLC.
Prepared By : MARY JANE R. ROGELIO
Invert-On-Zero Coding
ISO 3309
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Electronic Communications System By Wayne Tomasi
64)
Operational Mode of SDLC.
Normal Response Mode (NRM)
65)
A mode of operation logically equivalent
to a two point private line circuit where
each station has equal data link
responsibilities.
Asynchronous Balanced Mode
66)
A switched data communications network
similar to the public telephone network
except a PDN is designed for transferring
data only.
67)
It is used when making a standard
telephone call on the public telephone
network.
Circuit Switching
68)
Is a form of store and forward network.
Message Switching
69)
Another name for packet switching.
Public Switched Data Network (PDN)
Hold and Forward Network
70)
A user interface as the international
standard for packet network access.
X.25
71)
SA logically equivalent to a two point
dedicated private line circuit except
slower.
Permanent Virtual Circuit (PVC)
72)
A logically equivalent to making a
telephone call through the DDD network
except no direct end to end connection is
made.
Virtual Call
73)
Identifies whether the packet is a new call
request or a previously established call.
Format Identifier
Prepared By : MARY JANE R. ROGELIO
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BOOK REVIEW IN COMMUNICATIONS
Electronic Communications System By Wayne Tomasi
74)
A 12 bit binary number that identifies the
source and destination users for a given
virtual call.
Logical Channel Identifier
75)
This four bit gives the number of digits that
appear in the calling address filed.
Calling Address Field
76)
This field is the same as the calling address
field except that it identifies the number of
digits that appear in the called address
field
Called Address Length
77)
This field contains the destination address.
Called Address
78)
This field is the same as the called address
field except that it contains up to 15 BCD.
Calling Address
79)
This field identifies the number of eight bit
octets present in the facilities field.
Facilities Length Field
80)
This 32 bit field is reserved for the
subscriber to insert user level protocol.
Protocol Identifier
81)
A proposed network designed by the
major telephone companies in
conjunction with the ITU-T.
Integrated Services Digital Network
(ISDN)
82)
Customers gain access to the ISDN system
through a local interface connected to a
digital transmission medium.
83)
ISDN objectives that ensure universal
access to the network.
System Standardization
84)
Said objectives that allow customers to
use a variety of protocols and
applications
Achieving Transparency
Prepared By : MARY JANE R. ROGELIO
Digital Pipe
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Electronic Communications System By Wayne Tomasi
85)
ISDN should not provide services that
preclude competitiveness
86)
Provide private-line and switched services
refers what objectives of ISDN.
87)
ISDN services should not be directly
related to cost and independent of the
nature of the data.
88)
Provide a smooth transition while evolving.
Migration
89)
Provide service to low capacity personal
subscribers as well as to large companies.
Multiplexed Support
90)
Translation between non-ISDN data
protocol and ISDN is performed in this
device.
91)
A boundary to the network and may be
controlled by the ISDN provider.
92)
Refers to interfaces between the common
carrier subscriber loop and the central
office switch
93)
The media interface point between an
NT1 and the central office.
94)
It is defined by ITU-T as a service that
provides transmission channels capable of
supporting transmission rates greater than
the primary data rate.
95)
Information transfer is primarily from
service provider to subscriber
Prepared By : MARY JANE R. ROGELIO
Separating Functions
Variety of Configurations
Addressing Cost-Related Tariffs
Terminal Adapter
Network Termination 1
U-Reference Point
U Loop
Broadband ISDN
Distribution Services
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BOOK REVIEW IN COMMUNICATIONS
96)
97)
98)
99)
100)
Codes the data information into smaller
packets used by the BISDN network
A connection between a source and a
destination, which may entail several ATM
links.
Once data have entered the ATM
network, they transferred into fixed time
slots called ________.
Controls the flow of traffic across the user
network interface (UNI) and into the
network.
The first three bits of the second half of
byte 4 specify the type of message in cell.
Information fields that are designed to
accommodate PCM-TDM traffic, which
101)
allows the ATM network to emulate voice
or DSN services.
A portion of a public service provider's
switching system where the service
102)
provider could be a local telephone
company or a long-distance carrier.
Provides the most effective and
103) economical means of handling local data
communications field.
A communications system that allows
104) users to send messages to each other
through their computers.
105) LAN Topologies.
Prepared By : MARY JANE R. ROGELIO
Electronic Communications System By Wayne Tomasi
Broadband Node
Virtual Channel
Cells
Generic Flow Control Field (GFC)
Payload Type Identifier
Constant Bit Rate
Public ATM Switches
Local Area Networks (LAN)
E-Mails
Star, Bus and Ring Topology
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BOOK REVIEW IN COMMUNICATIONS
Electronic Communications System By Wayne Tomasi
106)
It describes how users access the
communications channel in a LAN.
107)
Access method used primarily in bus
topology.
108)
It two stations transmit at the same time,
________ occurs.
Collision
109)
The time it takes a signal to travel from a
source to a destination.
Propagation Delay
A base band transmission system
110) designed in 1972 by Robert Metcalfe and
David Boggs.
111)
Its purpose is to establish clock
synchronization.
112)
It is simply a series of two logic 1's
appended to the end of the preamble.
113)
Consists of six bytes the corresponds to the
address of the station sending the frame.
Prepared By : MARY JANE R. ROGELIO
Network Access Methodologies
CDMA/CD
Ethernet
Preamble
Start Frame Delimiter
Source Address
177