NE NE WAN Technologies 2

Question 1

What does 'last-mile connectivity' refer to in WAN terminology?

Accepted Answer

The physical connection between the service provider's network and the customer's premises

Answer

Last-mile connectivity is the link from the ISP's nearest point of presence (PoP) to the customer site, often the bottleneck in WAN performance.

Question 2

Which WAN technology uses asymmetric speeds and is delivered over existing telephone copper lines?

Accepted Answer

DSL (xDSL)

Answer

DSL delivers broadband over telephone copper pairs with faster download speeds than upload, with variants including ADSL, VDSL, and G.fast.

Question 3

What is the purpose of a WAN edge router?

Accepted Answer

To connect the enterprise LAN to the service provider WAN and manage routing policies

Answer

The WAN edge router sits at the boundary between the enterprise network and the service provider, handling routing protocols like BGP and policy enforcement.

Question 4

In MPLS networks, what is the role of the Label Edge Router (LER)?

Accepted Answer

To impose or dispose of MPLS labels at the edge of the MPLS domain

Answer

LERs (also called Provider Edge routers) add MPLS labels to incoming packets (ingress) and remove them at the destination edge (egress) of the MPLS domain.

Question 5

What is a CIR (Committed Information Rate) in Frame Relay or MPLS services?

Accepted Answer

The guaranteed minimum bandwidth the service provider commits to deliver

Answer

CIR is the contracted minimum bandwidth that the service provider guarantees to deliver under normal conditions; traffic above the CIR may be discarded during congestion.

NE - Network Engineer Practice Test

NE - Network Engineer Practice Test

NE NE WAN Technologies 2