Ch. 3 Fundamentals Of WANs Flashcards
How do LANs connect together using a WAN?
Via a router connected to each LAN with a WAN link between the routers
What do WANs do?
Forward data between two routers
How do you represent a leased line in a diagram
With a crooked line
A leased line delivers ____ in both directions using _____ _____
Bits, full duplex
A ____ _____ refers to a network a company pays to rent
Leased line
Today people refer to their leased lines as _____ _____ as a generic term
Service provider
Least circuit, circuit, serial link, serial line, point-to-point links, point to point line, T1, WAN link, link, private line are all types of
Leased lines
CO
Central office
CPE
Customer premises equipment
What does the CPE include
The router, serial interface card, and CSU/DSU
CSU
Channel service unit
DSU
Data service unit
DTE
Data terminal equipment (cables)
The serial cables normally used between a router and external CSU/DSU are called
Data terminal equipment (DTE)
DCE
Data communications equipment (cable) DCE
Leased lines provide what layer of service
Layer 1 physical
HDLC
High-level data link control
PPP
Point-to-point protocol
SP
Service provider
POP
Point of presence
EoMPLS
Ethernet emulation and ethernet over MPLS
MPLS
Multiprotocol label switching
What does EoMPLS provide
A point to point connection between two customer devices
Behavior as if a fiber ethernet link existed between the two devices
What are the two most popular data link layer protocols used for leased lines
High-level datalink control HDLC and PPP point to point protocol
Today most leased lines connect to _____
Routers
Routers focus on delivering packets to a
Destination host
A leased line with _____ creates a WAN link between two routers so that they can forward packets for the devices on the attached LANs
HDLC
What are the two names the CCENT and CCNA go by:
Ethernet emulation and ethernet over MPLs (EoMPLS)
The EoMPLS service provides
A point-to-point connection between two customer devices
Behavior as if a fiber ethernet link existed between the two devices
The EoMPLS link uses ethernet for both ______ and ______ functions
Layer 1 and layer 2
In networking terms the Internet is simply one huge _____ network
TCP/IP
The middle of the Internet is called
The Internet core
Who owns the Internet core
Internet service providers (ISP)
Enterprise TCP/IP networks use _____ ______
Leased lines
SOHO TCP/IP networks use _____ and _____
DSL and cable
Businesses primarily use ______ networks but can also use cable and DSL
Enterprise TCP/IP
All three of the Internet access technologies happen use a pair of _____. One of the customer side of the WAN link and one at the ISP side
Routers
DSL
Digital subscriber line
DSLAM
DSL access multiplexer
ISP towards the home
Downstream
Transmissions towards the ISP
Upstream
In DSL the downstream is much _____ compared to the upstream
Faster
WANs and LANs match which OSI layers
Layer 1 physical and layer 2 data link
WANs can connect devices that can Far apart, even ______ or _____ of ______
Hundreds or thousands of miles
The term lease liner first effect of the company using the least like does not____ the line but pays a monthly service to use it
Own
People today use the generic term ____ to refer to a company that provides any form of WAN connectivity
Service provider
Each site has a _____ which includes the router serial interface card and CSU/DSU
Customer premise equipment (CPE)
You treader uses a serial interface card the basically acts like a ______ ______ sending and receiving data over the physical link
Ethernet NIC
The physical link requires a function called a ______ _____ ______/______ ______ ______
Channel service unit(CSU)/data service unit(DSU)
The CSU/DSU normally provide a function called _______ in which it tells the router exactly when to send each bit by signaling over the serial cable
Clocking
A router serial interface can provide clocking, but the router does not do so unless configured with the _____ ______ command
Clock rate
A leased line with ______ protocol creates a ______ link between to routers so they can forward packets for the devices on the attached LANs
HDLC
WAN
The leased line itself provides the ______ means to transmit the bits in both directions
Physical
The ______ frames provide the means to encapsulate the network layer packet correctly so it crosses the link between routers
HDLC
What are the two names of the ethernet WAN service used for the CCNA
Ethernet emulation and ethernet over MPLS (EoMPLS)
DSL uses ______ ______ telephone line use for a typical home phone
Single pair
The main function of OSI layer 1 (physical)using WANs is
Delivery of bits from one device to another
In the cabling for a leased line what typically connect to a four wire line provided by Telco
CSU/DSU
An accurate speed at which at leased line can operate in the United States is
256 Kbps
What field does Cisco routers add beyond the ISO and standard HDLC
Type
Two routers R1 and R2 connect using an ethernet over and MPLS service. The service provides point-to-point service between these two routers only as a layer 2 ethernet service. Name two things that are likely to be true about this WAN
R1 will connect to a physical ethernet link with the other end of the cable connected to the device with the WAN service provider point of presence
R1 will forward data link frames to R2 using an ethernet Header/trailer
Name two Internet access technologies used to connect to a site on an ISP that offer asymmetric speed
DSL and cable
Fred has just added DSL service at his home with a separate DSL modem and consumer grade router with four ethernet ports. Fred wants to use the same old phone he was using before the installation of DSL. What is most likely true about the phone cabling and phone used with his new DSL installation
He uses the old phone cabled to an existing telephone cord and not to any new device
What is a telco
Telephone Company
