语音与数据通信手册（英文影印版）

.　　and telecommunications principles. No magic exists here, merely an
　　understanding of what telecommunications is all about: the principles of
　　a telephone, the line connections employed, the forms of communica-
　　tions used, and an understanding of the telephone company networks.
　　We intend to make .things as simple as possible as we cover the various
　　techniques and terminology used throughout this book. Be aware, how-
　　eves that no matter how simple we attempt to make this information and
　　no matter how smoothly we attempt to steer you through the guides out-
　　lined, this is a technical subject. Therefore, from time to time we may start
　　sounding a little "techie" This is not done to impress or confuse you—we
　　just cannot think of a way to make our explanation any more basic with-
　　out destroying the flow. At any rate, this book is designed to give you a
　　fundamental understanding of the overall concepts used in the telecom-
　　munications arena, both voice and data.
　　

. the local loop
the network hierarchy (pre-1984)
the network hierarchy (post-1984)
the public-switched network
the north american numbering plan
the area code
the exchange code
the subscriber extension
private networks
hybrid networks
local access and transport areas (latas)
wiring connections: hooking things up
types of communications
equipment
chapter 4 the telephone sec
the function of the telephone set
the pieces
newer sets
chapter s analog versus digital transmission
introduction
analog transmission systems
analog-to-digital conversion
digital signaling
digital data in an analog world
chapter 6 carriers
local exchange carriers
competitive local exchange carriers (clecs)
interexchange (iec/ixc) carriers
value-added carriers
alternate operator services
aggregators
competitive access providers
resellers
chapter 7 lines versus trunks
introduction
did
dod
fx
ofx
tie lines
wats
private line
comments on lina and trunk networking
chapter 8 traffic engineering
where can the information be obtained?
accomplishing the mission
using the information
chapter 9 equipment: private branch exchanges
private branch exchange (pbx)
analog systems
digital pbx
central office centrex
centrex service
peripheral devices
chapter 10 key telephone systems
why key systems?
vendor interfaces
key players in the key system marketplace
chapter 11 voice processing
introduction
control alternatives: touch-tone or voice
recognition
automated attendant
a few important points not directly illustrated in
the dialogue
automatic call distributor
voice mail
interactive voice response
chapter 12 computer-to-telephony integration (cti)
other applications
why all the hype?
linking computers and communications
the technology advancement
the final bond
technology enhancements
other technologies
summary
chapter 13 data communications
concepts
architectures
protocols
transmission protocols (synchronous vs.
asynchronous)
error detection
parity bit/vertical redundancy checking (vrc)
longitudinal redundancy checking (lrc)
cyclic redundancy checking (crc)
plexes—ommunications channel directions
compression
multiplexing
codes
modulation
devices
modems
chapter 14 t1 and the t-carrier system
evolution of the t-carrier system
analog transmission basics
the evolution to digital
analog-to-digital conversion
the movement to end users
ti basics
framed format
bipolar
byte synchronous
channelized versus nonchannelized
digital capacities
signaling
clocking (network synchronization)
performance issues
d3/d4 framing
maintenance issues
error detection
errors of omission/commission
esf—a step to correct the problem
framing
the facility data link
benefits of esf
problems with esf
chapter 15 the open systems interconnect model (osi)
other network architectures
sna
sna components
the sscp
the physical unit
the logical unit
digital network architecture (dna)
internet protocols (tcp/ip)
ip
tcp
chapter 16 internet
introduction
a little history
structure (who's at the center—and why)
why the hype?
everybody as a publisher
commercial opportunity?
spam
web advertising
web site
protocols
naming standards
gaining access
internet futures
chapter 17 intranet
introduction
issues
the architecture
accessing the network
intranet: the logical evolution
is it for everyone?
the full-service intranet
applications
getting there from here
other issues
chapter 18 packet switching technologies (x.25)
data communications problems
the data communications review
packet switching defined
what is packet switching?
the packet switching analogy
the paget concept
overhead
summary of packet format
the packet network
the user connection
benefits of packets
oeher benefits
advantages of packet switching
other components of packet switching
the x.25 numbering plan
applications for x.25 services
other forms of packets
chapter 19 local area networks (lans)
what are lans?
a lan by another name
why they are used
distributed systems
client/server architecture
how they work
topologies
internetworking
chapter 20 ethernet
concepts
components
fast ethernet
chapter 21 token ring lans
token rings
the ibm token concept
initial layout
problems encountered
the solution to physical problems
cable types used
speeds
media access control layer
the frame
the token
the abort sequence
the frame
case example
chapter 22 baseband versus broadband
baseband and broadband
motivations driving the lan decision
broadband cable systems
baseband vs. broadband
chapter 23 fiber distributed data interface
fddi design
fddi configuration
fddi on the osl model
the fddi frame
synchronization
fddi applications
fddi in the man
fddi recovery
fddi-ii
fast ethernet
ethernet switching
chapter 24 switched multimegabit data services
what is smds?
the local environment
technology used in smds
the smds goal
access rates to smds
accessing the man
the ieee 802.6 architecture
the dqdb architecture
the man access unit
the data handling
information throughput
future services on smds
chapter 25 frame relay
what is frame relay?
why was frame relay developed?
the significance of frame relay
comparing frame relay to other services
frame relay speeds
guaranteed delivery
advantages of frame relay services
services available
frame relay standards
the major players
others
lmi specification
what the standards state
voice over frame relay
equipment
international
advantages
disadvantages
chapter 26 integrated services digital network
what is isdn?
isdn defined
who is making the rules?
why do we need isdn?
the overall isdn concept
integration
the isdn architecture
physical view
logical view
architecture reality
basic operating characteristics
bearer services
clear-channel capability
applications for isdn
isdn centrex versus pbx service
centrex
isdn pbx capabilities
applications for isdn in vertical markets
messages and frame formats
chapter 27 asynchronous transfer mode
atm capabilities
what is atm?
broadband communications
time-division multiplexing
the digital hierarchy
sonet
the cell concept
the importance of cells
cell sizes and formats
the cell format for user data
the adaptation layer
atm standards protocols
equipment
atm in the lan environment
evaluating the need for atm
what to expect at the desktop
lan to lan via atm
lan to man via atm
local exchange carriers
interexchange carriers
cap and cable tv suppliers
catv companies
application needs driving
assess the situation
chapter 28 cellular and personal communications systems
radio transmission
problems with the amps/imts
cellular communications
meeting the demand
the telephone (mobile) set
cellular's success and loss
digital transmission
voice technology and applications
facsimile technology
data transmission
digital cellular evolution
personal communications services
technology
the concept of pcs/pcn
why personal communications?
the evolution of personal communications
comparing pcs to cellular networks
chapter 29 radio systems
radio-based systems
satellite
very small aperture terminals (vsats)
microwave
future use of microwave and satellite systems
chapter 30 light systems
system geometry
atmospheric conditions
site selection
licensing requirements
bandwidth capacities
applications
can the system carry lan traffic transparently?
advantages of infrared
disadvantages of infrared
fiber-optic compatible systems
chapter 31 video conferencing
video conferencing systems
what is video conferencing?
video conferencing overview
the parts of a video system
standards in video conferencjng
multipoint control units
connecting the parts
chapter 32 finances for telecommunications
introduction
benefits
costs
pricing considerations
chapter 33 facsimile
facsimile transmission
types of fax
printing options
fax boards
common uses of fax
future machines
chapter 34 cabling systems
introduction
twisted pair
coax
fiber optics
applications of fiber
fiber differences
fiber futures and risks
appendix
index