Introducing WAN Technologies Flashcards
Which medium is used by service providers to transmit data over WAN connections with SONET or SDH?
A. fiber optic
B. satellite
C. WiFi
D. coaxial cable
A. fiber optic
Which three statements about WAN devices are true? (Choose three.)
A. A DSL modem is a DCE device.
B. A fiber converter is a DTE.
C. A CSU/DSU is used when communicating over analog circuits.
D. A router is connected to the DSU component of the CSU/DSU device.
E. A fiber converter can be part of the CPE.
F. A DCE device is always owned by the service provider.
A. A DSL modem is a DCE device.
D. A router is connected to the DSU component of the CSU/DSU device.
E. A fiber converter can be part of the CPE.
The correct answers are: “A DSL modem is a DCE device,” “A router is connected to the DSU component of the CSU/DSU device,” and “A fiber converter can be part of the CPE.” A modem is always a DCE device, even when it is a module in a DTE device. A fiber converter is used to connect to the provider’s fiber circuit, therefore it is a DCE and not the DTE devices. CSU/DSU devices are used when communication over digital and not analog lines. Modems are used with analog lines. As any other DCE, a fiber converter can be owned and managed by the enterprise, hence part of customers premises equipment. It can also be leased from the provider, for example, not owned, and managed by the provider.
Which statement regarding WAN topologies is true?
A. WAN topologies, such as hub-and-spoke and partial mesh, are physical topologies.
B. Dual homed hub-and-spoke WAN topology is implemented using one hub device with different interfaces and subinterfaces acting as separate hubs.
C. WAN point-to-point connections are such that remote devices seem to be on the same physical segment.
D. Full mesh topologies are scalable.
E. Partial mesh topologies provide for the highest level of redundancy.
C. WAN point-to-point connections are such that remote devices seem to be on the same physical segment.
The correct answers is: “WAN point-to-point connections are such that remote devices seem to be on the same physical segment.” Point-to-point topology establishes a circuit (a logical connection) between exactly two sites. It is also called a Layer 2 service as it creates a connection, via which it seems that both sites are on the same physical segment.
Which statement about WAN connections is true?
A. WAN connections are defined as connections over a public infrastructure.
B. The WAN connection type that is used on the last mile must be the same WAN connection type that is employed within the service provider network or for interconnecting various service providers.
C. The VPN technology makes the internet an inexpensive and secure option for connecting to remote offices.
D. The ATM technology requires the establishment of a connection through a service provider network before communication can start.
C. The VPN technology makes the internet an inexpensive and secure option for connecting to remote offices.
The correct answer is “The VPN technology makes the internet an inexpensive and secure option for connecting to remote offices.” Only internet-based connections are using the public infrastructure, other WAN options are utilizing private service provider networks. WAN service provider can have one network interconnecting all enterprise’s locations or it can interconnect with other providers to ensure the required geographic coverage. The access technology of one provider may differ from the access technology of another, and yet another technology may be employed on providers’ interlinks. The ATM is a packet-switched technology, and not circuit-switched.
When establishing a VPN tunnel in site-to-site deployment, the VPN tunnel is established between which two end-points?
A. local and remote VPN gateway devices
B. individual host and the remote VPN terminating network device
C. local and remote individual hosts
D. individual host and the local VPN gateway device
A. local and remote VPN gateway devices
The correct answer is “local and remote VPN gateway devices.” In site-to-site VPN deployment, the end-device (for example, the individual host) is not establishing the tunnel. The tunnel is established between edge devices at remote locations.
Which statement about VPLS is true?
A. VPLS is managed by the enterprise.
B. VPLS is a cryptographic VPN.
C. VPLS is a Layer 3 VPN.
D. VPLS is an MPLS-based VPN.
D. VPLS is an MPLS-based VPN.
The correct answer is “VPLS is an MPLS-based VPN.” The underlying technology that implements VPLS is MPLS and it is provider managed and not under the control of an enterprise. Unlike IPsec-based VPNs, VPLS itself does not implement cryptographic functions. VPLS is a Layer 2 VPN where the providers network behaves as a huge switch that connects enterprise remote locations.
Which two statements about provider-managed VPNs are true? (Choose two.)
A. Provider-managed VPNs are used when remote sites connect over internet.
B. Provider-managed Layer 2 MPLS VPNs do not isolate customers’ traffic.
C. Provider-managed VPNs use IPSec to isolate customers’ traffic.
D. Provider-managed Layer 3 MPLS VPNs make the provider’s network appear as a router for each connected customer.
E. Provider-managed Layer 2 MPLS VPNs make remote customer sites appear as directly connected.
D. Provider-managed Layer 3 MPLS VPNs make the provider’s network appear as a router for each connected customer.
E. Provider-managed Layer 2 MPLS VPNs make remote customer sites appear as directly connected.
Which statement regarding WANs is true?
A. A WAN and the internet both cover wide geographic areas and they are the same.
B. WANs use services of carriers that manage large networks, which can be based on different technologies, such as telephony, cable, satellite and others.
C. WAN is necessary to connect distant locations of an enterprise.
D. WAN infrastructures are impossible to set without an existing carrier.
B. WANs use services of carriers that manage large networks, which can be based on different technologies, such as telephony, cable, satellite and others.
Which of the basic ISP connectivity types provides the highest redundancy?
A. single-homed
B. dual-homed
C. multihomed
D. dual-multihomed
D. dual-multihomed
Considering only the technical aspects of WAN connections, which topology would you choose if your primary concern was to enable good voice conversation experience among three enterprise offices?
A. dual homed hub-and-spoke
B. partial mesh
C. hub-and-spoke
D. full mesh
E. internet-based cryptographic VPNs
D. full mesh
Which statement about site-to-site VPN deployment mode is true?
A. End-devices that source messages are aware that VPN exists between them and the remote location.
B. In cryptographic VPN site-to-site deployment, the end-device encrypts the content to be sent over the VPN.
C. Hub-and-spoke is the only VPN topology that can be implemented to interconnect more than two remote locations.
D. In a site-to-site VPN, a tunnel is built between VPN gateways present at each of the sites.
D. In a site-to-site VPN, a tunnel is built between VPN gateways present at each of the sites.
Which two options are site-to-site VPN options? (Choose two.)
A. Frame Relay
B. DSL
C. DMVPN
D. ATM
E. IPsec
C. DMVPN
E. IPsec
Which optical technology provides highest data rates?
A. SONET
B. FTTx
C. DWDM
D. SDH
C. DWDM
Which wired broadband internet access technology option uses twisted-pair telephone lines for transport?
A. DOCSIS
B. LTE
C. FTTx
D. ADSL
D. ADSL
Which three options are classified as internet-based WAN connectivity options? (Choose three.)
A. MPLS
B. Metro Ethernet
C. xDSL
D. cable
E. T1/E1
F. cellular 4G
C. xDSL
D. cable
F. cellular 4G
