1. 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?
Explanation: A WAN connects multiple LANs that are in geographically separated locations. A MAN connects multiple LANs in a large campus or in a city. WLAN is a wireless LAN that covers a rather small geographic area.
2. What is the recommended technology to use over a public WAN infrastructure when a branch office is connected to the corporate site?
- VPN
- ATM
- municipal Wi-Fi
- ISDN
Explanation: ISDN and ATM are Layer 1 and 2 technologies that are typically used on private WANs. Municipal WiFi is a wireless public WAN technology. Corporate communications over public WANs should use VPNs for security.
3. Which medium do service providers use to transmit data over WAN connections with SONET, SDH, and DWDM?
- satellite
- copper
- fiber optic
- Wi-Fi
Explanation: Technologies such as SONET, SDH, and DWDM are designed to run over fiber optic cables.
4. Which statement describes a characteristic of a WAN?
- WAN networks are owned by service providers.
- All serial links are considered WAN connections.
- A WAN operates within the same geographic scope of a LAN, but has serial links.
- A WAN provides end-user network connectivity to the campus backbone.
Explanation: WANs are used to interconnect the enterprise LAN to remote branch site LANs and telecommuter sites. A WAN is owned by a service provider. Although WAN connections are typically made through serial interfaces, not all serial links are connected to a WAN. LANs, not WANs, provide end-user network connectivity in an organization.
5. Which type of network would be used by a company to connect locations across the country?
Explanation: A wide-area network (WAN) provides network connectivity over a wide geographical area compared to a local-area network (LAN) that is usually limited to connecting devices in a room or building. A storage-area network (SAN) contains storage media such as hard drive disk arrays that provide storage for applications and servers. A wireless LAN (WLAN) provides connectivity for wireless devices in a limited space.
6. 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
- Virtual Private Networks that would enable the company to connect easily and securely with employees
- private dedicated lines through their local service provider
- a dialup connection that is supplied by their local telephone service provider
Explanation: For this small office, an appropriate connection to the Internet would be through a common broadband service called Digital Subscriber Line (DSL), available from their local telephone service provider. With so few employees, bandwidth is not a significant problem. If the company were bigger, with branch offices in remote sites, private lines would be more appropriate. Virtual Private Networks would be used if the company had employees who needed to connect to the company via Internet.
7. To which two layers of the OSI model do WAN technologies provide services? (Choose two.)
- presentation layer
- data link layer
- network layer
- physical layer
- transport layer
- session layer
Explanation: WAN operations focus primarily on the physical layer and the data link layer of the OSI model.
8. 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?
- circuit-switched network
- MPLS
- packet-switched network
- Ethernet WAN
Explanation: MPLS can use a variety of underlying technologies such as T- and E-Carriers, Carrier Ethernet, ATM, Frame Relay, and DSL, all of which support lower speeds than an Ethernet WAN. Neither a circuit-switched network, such as the public switched telephone network (PSTN) or Integrated Service Digital Network (ISDN), nor a packet-switched network, is considered high speed.
9. 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? (Choose two.)
- cellular
- dedicated
- private infrastructure
- circuit-switched
- public infrastructure
Explanation: Public cellular networks provide a highly mobile Internet connection at high data rates.
10. 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?
- full mesh
- bus
- mesh
- point-to-point
- hub and spoke
Explanation: A point-to-point topology only connects two nodes. A bus is a legacy topology for LANs. Mesh and full mesh topologies have more connectivity than needed (all or most of the branches will be connected to each other). A hub and spoke design will connect the headquarters to all its branches, as desired.
11. What is a characteristic of a WAN?
- WAN service providers include carriers such as a telephone network or satellite service.
- A WAN is typically owned by an enterprise which wants to interconnect its LANs.
- A WAN operates inside the geographic scope of a LAN.
- WANs always use physical cables to connect LANs.
Explanation: A WAN operates beyond the geographic scope of a LAN and it is owned by a service provider. WANs are used to interconnect the enterprise LAN to remote LANs in branch sites and telecommuter sites. WAN service providers include carriers such as a telephone network, cable company, or satellite service. It is not feasible to connect LANs across a country, or around the world, with physical cables.
12. What are two common types of circuit-switched WAN technologies? (Choose two.)
- DSL
- Frame Relay
- ISDN
- ATM
- PSTN
Explanation: The two most common types of circuit-switched WAN technologies are the public switched telephone network (PSTN) and the integrated services digital network (ISDN). Frame Relay and ATM are packet-switched WAN technologies. DSL is a WAN technology that offers broadband Internet access.
13. A new corporation needs a data network that must meet certain requirements. The network must provide a low cost connection to sales people dispersed over a large geographical area. Which two types of WAN infrastructure would meet the requirements? (Choose two.)
- public infrastructure
- dedicated
- satellite
- private infrastructure
- Internet
Explanation: VPNs over the Internet provide low cost, secure connections to remote users. VPNs are deployed over the Internet public infrastructure.
