Module 7: Wan Concepts Flashcards
A teleworker woud like to bundle the internet connection with other phone and TV services, what type of WAN scenario is this?
Cable
A company requires higher download speeds than upload speeds and wants to use existing phone lines, what type of WAN scenario is this?
DSL
A company has a headquarters and four remote locations. The headquarters requires more bandwidth than the four remote sites, what type of WAN scenario is this?
Frame Relay
A multi-site college wants to connect using Ethernet technology between the sites, what type of WAN scenario is this?
MetroE
A company would like guaranteed bandwidth using a point-to-point link that requires minimal expertise to install and maintain, what type of WAN scenario is this?
T1
Which situation describes data transmissions over a WAN connection?
An employee shares a database file with a co-worker who is located in a branch office on the other side of the city.
Which technologies are categorized as private WAN infrastructures?
Leased lines, dialup, ISDN, Frame Relay, ATM, Ethernet WAN (e.g. MetroE), MPLS, and VSAT
True or False? WANs are typically operated through multiple ISPs, but LANs are typically operated by single organisations or individuals.
True
True or False? Both LANs and WANs connect end devices.
False
True or False? WANs connect LANs at slower speed bandwidth than LANs connect their internal devices
True
True or False? LANs connect multiple WANs together.
False
True or False? WANs must be publicly-owned, but LANs can be owned by either public or private entities.
False
Which WAN infrastructure services are examples of private connections?
T1/E1, T3/E3, PSTN, ISDN, MetroE, MPLS, Frame Relay, ATM, or VSAT
Which WAN infrastructure services are examples of public connections?
DSL, Cable, or Wireless
What is a Public WAN?
A WAN connection typically provided by an ISP, which typically offers variable service levels, inconsistent bandwidth and limited security.
What is a Private WAN?
A WAN connection that is dedicated to a single customer, which typically offers guaranteed service levels, consistent bandwidth and security.
True or False? A WAN is owned and managed by an organisation or home user?
False
True or False? A WAN provides networking services over large geographical areas.
True
True or False? WAN services are provided for a fee.
True
True or False? WANs provide low bandwidth speeds over short-distances.
False
True or False? WANs guarantee security between endpoints.
False
Which topology type describes the virtual connection between source to destination?
Logical topology
Which type of WAN network design is the most fault-tolerant?
Fully meshed topology
Which type of WAN network design is often used to connect routers to other routers, or switches to other switches?
Point-to-point topology
Which is a type of WAN carrier connection that provides redundancy?
Dual-carrier WAN connection, via two different ISPs each using a different carrier.
Which two OSI Layers do most WAN standards focus on?
Layer 1 (Physical) and Layer 2 (Data Link)
What is Data Terminal Equipment (DTE) and what does it do?
Typically a router, but sometimes directly a host or server. It is the device that connects to the WAN provider owned device Data Communications Equipment (DCE)
What is Data Communications Equipment (DCE) and what does it do?
It is the service provider provided device, that is used to communicate with the provider. It provides a WAN interface to connect the subscriber (customer) to a communication link on the WAN cloud.
What is Customer Premises Equipment?
It is the DTE and DCE devices (i.e. router, modem, optical converter). The subscriber either owns the CPE themselves or leases it from the service provider.
What is the Point-of-Presence (POP)
The point where the subscriber connects to the service provider network.
What is the demarcation point?
The physical location in the building or premises that officially separates the CPE from service provider equipment. Typically a junction box that connects the CPE wiring to the local loop.
What is the Local Loop (or last mile)?
The copper or fibre cable that connects the CPE to the central office of the service provider.
What is the Central Office (CO)?
The local service provider facility or building that connects the CPE to the provider backhaul network.
What is the Toll Network?
A legacy name for the part of the service providers network beyond the local area. Named because telephone calls outside the local area were charged an additional toll (e.g. local rate versus long distance calls)
What is the Backhaul Network?
The service provider network that connects the edge or access networks, such as central offices to the backbone network.
What is the Backbone Network?
The service provider high-speed core network that connects regionally or globally, and to other service provider owned backbone networks for worldwide communications.
What is Serial Communication?
Transmitting bits sequentially over a single channel / line.
What is Parallel Communication?
Transfering several bits using multiple wires at the same time.
Why is parallel communication limited to shorter distances?
The longer the distance the more prone to synchronisation problems the parallel communication becomes.
True or False?
Circuit-switch communications form a direct connection between the sender and receiver
True
In packet-switched communications what two issues can arise?
Delay (latency) and variability in delay (jitter)
Which service provider fiber-optic technology increases the data-carrying capacity using different wavelengths?
Dense Wavelength Division Multiplexing (DWDM)
True or False?
The WAN OSI Layer 1 describes how data will be encapsulated into a frame?
False.
That is Layer 2
True or False?
The WAN OSI Layer 1 describes the electrical, mechanical, and operational components needed to transmit bits.
True.
True or False?
The WAN OSI Layer 1 includes procotols such as PPP, HDLC, and Ethernet.
False.
That is Layer 2
True or False?
The WAN OSI Layer 1 includes protocols such as SDH, SONET, and DWDM.
True.
Which communication method is used in all WAN connections?
Serial communication
Which WAN term defines the point where the subscriber connects to the service providers network?
Point-of-Presence (POP)
Which WAN connectivity options are packet-switched technologies?
Ethernet WAN, ATM and Frame Relay
Which two devices operate in a similar manner to the voiceband modem but use higher broadband frequencies and transmission speeds?
Cable Modem and DSL Modem
Which two WAN connectivity options are circuit-switched technologies?
ISDN and PSTN
Which traditional WAN connectivity option uses T-Carrier or E-Carrier lines?
Leased lines
Which service provider WAN solution uses labels to direct the flow of packets through the provider network?
MPLS (Multiprotocol Label Switching)
Which WAN connectivity option is based on Ethernet LAN technology?
MetroE (Metro Ethernet)
A company is expanding its business to other countries. All branch offices must remain connected to corporate headquarters at all times. Which network technology is required to support this scenario?
WAN
What is the recommended technology to use over a public WAN infrastructure when a branch office is connected to the corporate site?
VPN
Which medium do service providers use to transmit data over WAN connections with SONET, SDH, and DWDM?
Fibre optic
Which statement describes a characteristic of a WAN?
WAN networks are owned by service providers.
Which type of network would be used by a company to connect locations across the country?
WAN
A small company with 10 employees uses a single LAN to share information between computers. Which type of connection to the Internet would be appropriate for this company?
A broadband service, such as DSL, through their local service provider
To which two layers of the OSI model do WAN technologies provide services?
Physical layer and Data link layer
A customer needs a metropolitan area WAN connection that provides high-speed, dedicated bandwidth between two sites. Which type of WAN connection would best fulfill this need?
Ethernet WAN
An intercity bus company wants to offer constant Internet connectivity to the users traveling on the buses. Which two types of WAN infrastructure would meet the requirements?
Public infrastructure and Cellular
An enterprise has four branches. The headquarters needs full connectivity to all branches. The branches do not need to be connected directly to each other. Which WAN topology is most suitable?
Hub and spoke
