Module 7 - WAN Concepts

Which situation describes data transmissions over a WAN connection?

• An employee prints a file through a networked printer that is located in another building.

• A manager sends an email to all employees in the department with offices that are located in several buildings.

• An employee shares a database file with a co-worker who is located in a branch office on the other side of the city.

• A network administrator in the office remotely accesses a web server that is located in the data center at the edge of the campus.

Answer explanation

When two offices across a city are communicating, it is most likely that the data transmissions are over some type of WAN connection. Data communications within a campus are typically over LAN connections.

A company is considering updating the campus WAN connection. Which two WAN options are examples of the private WAN architecture? (Choose two.)

• cable

• leased line

• Ethernet WAN

• municipal Wi-Fi

• digital subscriber line

Answer explanation

An organization can connect to a WAN through basic two options:

Private WAN infrastructure - such as dedicated point-to-point leased lines, PSTN, ISDN, Ethernet WAN, ATM, or Frame Relay

Public WAN infrastructure - such as digital subscriber line (DSL), cable, satellite access, municipal Wi-Fi, WiMAX, or wireless cellular including 3G/4G

Which two technologies are categorized as private WAN infrastructures? (Choose two.)

• cable

• DSL

• Frame Relay

• MetroE

• VPN

Answer explanation

Private WAN technologies include leased lines, dialup, ISDN, Frame Relay, ATM, Ethernet WAN (an example is MetroE), MPLS, and VSAT.

Which network scenario will require the use of a WAN?

• Employee workstations need to obtain dynamically assigned IP addresses.

• Employees need to connect to the corporate email server through a VPN while traveling.

• Employees in the branch office need to share files with the headquarters office that is located in a separate building on the same campus network.

• Employees need to access web pages that are hosted on the corporate web servers in the DMZ within their building.

Answer explanation

When traveling employees need to connect to a corporate email server through a WAN connection, the VPN will create a secure tunnel between an employee laptop and the corporate network over the WAN connection. Obtaining dynamic IP addresses through DHCP is a function of LAN communication. Sharing files among separate buildings on a corporate campus is accomplished through the LAN infrastructure. A DMZ is a protected network inside the corporate LAN infrastructure.

Which circumstance would result in an enterprise deciding to implement a corporate WAN?

• when its employees become distributed across many branch locations

• when the network will span multiple buildings

• when the number of employees exceeds the capacity of the LAN

• when the enterprise decides to secure its corporate LAN

Answer explanation

WANs cover a greater geographic area than LANs do, so having employees distributed across many locations would require the implementation of WAN technologies to connect those locations. Customers will access corporate web services via a public WAN that is implemented by a service provider, not by the enterprise itself. When employee numbers grow, the LAN has to expand as well. A WAN is not required unless the employees are in remote locations. LAN security is not related to the decision to implement a WAN.

Which two WAN infrastructure services are examples of private connections? (Choose two.)

• T1/E1

• wireless

• DSL

• cable

• Frame Relay

Answer explanation

Private WANs can use T1/E1, T3/E3, PSTN, ISDN, Metro Ethernet, MPLS, Frame Relay, ATM, or VSAT technology.

Which two statements about the relationship between LANs and WANs are true? (Choose two.)

• Both LANs and WANs connect end devices.

• WANs connect LANs at slower speed bandwidth than LANs connect their internal end devices.​

• LANs connect multiple WANs together.

• WANs must be publicly-owned, but LANs can be owned by either public or private entities.

• WANs are typically operated through multiple ISPs, but LANs are typically operated by single organizations or individuals.

Answer explanation

Although LANs and WANs can employ the same network media and intermediary devices, they serve very different areas and purposes. The administrative and geographical scope of a WAN is larger than that of a LAN. Bandwidth speeds are slower on WANs because of their increased complexity. The Internet is a network of networks, which can function under either public or private management.

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?

• mesh

• full mesh

• point-to-point

• bus

• hub and spoke

Match the scenario to the WAN solution.

• Demarcation Point

• customer devices that pass the data from a customer network or host computer for transmission over the WAN

• Customer Premises Equipment

• a point that is established in a building or complex to separate customer equipment from service provider equipment

• Data Terminal Equipment

• devices that put data on the local loop

• Data Communication Equipment

• devices and inside wiring located on the enterprise edge and which connect to a carrier link

Match the scenario to the WAN solution.

• T1

• A company has a headquarters and four remote locations. The headquarters site will require more bandwidth than the four remote sites.

• cable

• A teleworker would like to bundle the internet connection with other phone and TV services.

• Frame Relay

• A company would like guaranteed bandwidth using a point-a-point link that requires minimal expertise to install and maintain.

• MetroE

• A company requires higher download speeds than upload speeds and wants to use existing phone lines.

• DSL

• A multisite college wants to connect using Ethernet technology between the sites.