Chapter 16 Flashcards
are communications networks that cover broad geographic areas that still frequently use phone companies (service providers) along with their circuit-switched networks to connect LANs together. p576
WANs
WAN service type from a provider typically use: p577
Customer premises equipment (CPE) Channel service unit/data service unit (CSU/DSU) Demarcation point Smart Jack/NIU Copper Line Drivers/Repeaters Local loop Central office (CO) Toll network
is a Layer 1 device that connects your serial ports on your router to the provider’s network and connects directly to the demarcation point (demark) or location. p577
Channel service unit/data service unit (CSU/DSU)
What is a Demarcation point p578
The demarc is the precise spot where the service provider’s (local exchange carrier) responsibility ends and the CPE begins. It’s generally a device in a telecommunications closet owned and installed by the telecommunications company (telco).
What is a Local loop. p579
A cable consisting of a pair of copper wires called the local loop connects the demarc to the closest switching office known as a central office (CO).
What is a Central office (CO).p 579
A phone company building that connects the customer’s network to the provider’s switching network. Good to know is that a CO is sometimes referred to as a point of presence (POP).
What is a Toll network. p579
The toll network is a trunk line inside a WAN provider’s network. This network is a collection of switches and facilities owned by the ISP.
The portion of the PSTN that runs from your house to the rest of the world is known as. p579
plain old telephone service (POTS)
Two key concepts to keep in mind about PSTN are. p579
public and switched
basically means that, for a fee, anyone can lease the use of the network without having to deal with running any cabling. p579
Public
is a pre-established WAN communications path that goes from the CPE through the DCE switch and then over to the CPE of the remote site. p580
dedicated leased line
uses dial-up modems or ISDN and is used for low-bandwidth data transfers. p581
Circuit switching
can be thought of as a network that’s designed to look like a leased line yet charges you more like circuit switching does. p581
Packet switching
What are some WAN connection types. p580-81
Packet switching
Circuit switching
dedicated leased line
Modems are required to _______________ the signal, which means translating the analog signal our ears hear into a digital stream for transfer across a digital network. p582
modulate/demodulate
The basic, first level in bandwidth or speed for leased lines that provide synchronous connections between sites is known as the. p582
T1 line. It serves up 24 Digital Signal 0 (DS0), 64Kbps channels in our country, Japan, and South Korea
what is the maximum speed for T1. p583
1.544Mbps
what is the maximum speed for T1C
3.152Mbps
what is the maximum speed for T2
6.312Mbps
what is the maximum speed for T3
44.736Mbps
what is the maximum speed forT4
274.176Mbps
Another aspect of WAN technologies that can have a big effect on the speed, bandwidth, and the volume of data that can be transferred is the type of ____________.p584
Transmission Media
In the U.S, the standard for synchronous data transmission on optical fiber is called. p585
Synchronous Optical Network (SONET)
SONET defines a base data rate, or throughput, of 51.84Mbps, and multiples of this rate are known as. p585
optical carrier (OC)
The data rate for OC-1
51.84Mbps
The data rate for OC-3
155.52Mbps
The data rate for OC-12
622.08Mbps
The data rate for OC-48
2.488Gbps
The data rate for OC-192
9.953Gbps
Is a technology that multiplexes several optical carriers on a single optical fiber by using different wavelengths. p585
Wavelength Division Multiplexing (WDM)
Multiplexes within a specific band allowing for the use of erbium-doped fiber amplifiers (EDFA) that boost the signal. p585
Dense Wavelength Division Multiplexing
is a technology for transmitting digital and sometimes even analog signals between two locations on a line-of-sight radio path through the atmosphere. p587
Microwave radio relay
is an artificial satellite stationed in space for telecommunications purposes.p587
communications satellite (comsat)
It was typically used to interconnect local-exchange carrier systems and to carry high-speed corporate data links and voice channels using T1 lines. p590
High bit-rate digital subscriber line (HDSL)
It’s typically used by small to medium-sized businesses that don’t require the higher performance of a leased line for connecting to a server. p590
Symmetric digital subscriber line (SDSL)
is capable of supporting high-bandwidth applications like HDTV, telephone services like the popular Voice over IP (VoIP), as well as general Internet access over a single connection. p590
Very high Bit-rate digital subscriber line (VDSL)
This makes downloading graphics, audio, video, and data files from any remote computer a snap. p591
Asymmetric digital subscriber line (ADSL)
