NE NE WAN Technologies 3

Question 1

What is the main purpose of BGP (Border Gateway Protocol) in WAN environments?

Accepted Answer

To exchange routing information between autonomous systems (ASes) on the internet

Answer

BGP is the internet's routing protocol, exchanging prefix reachability between ASes and enabling policy-based routing decisions at ISP and enterprise boundaries.

Question 2

What is dual-homing in WAN design?

Accepted Answer

Connecting a site to two different service providers or two separate circuits for redundancy

Answer

Dual-homing connects a site to two ISPs or two circuits, ensuring connectivity if one provider or link fails — a common high-availability WAN design.

Question 3

Which metric does MPLS Traffic Engineering (TE) use to calculate constrained paths across the network?

Accepted Answer

Bandwidth, delay, and administrative constraints via RSVP-TE or OSPF-TE extensions

Answer

MPLS-TE uses extensions to OSPF or IS-IS to flood topology and bandwidth information, then RSVP-TE signals explicit LSPs that satisfy bandwidth and policy constraints.

Question 4

What is the role of a CPE (Customer Premises Equipment) in a WAN service?

Accepted Answer

Hardware owned by the ISP placed at the customer site to terminate the WAN circuit

Answer

CPE is equipment located at the customer site; it may be ISP-owned (like a modem or ONT) or customer-managed (like a router), serving as the WAN demarcation point.

Question 5

In the context of WAN SLAs, what does jitter measure?

Accepted Answer

Variation in packet delay over time

Answer

Jitter is the variation in packet inter-arrival times; high jitter degrades real-time applications like VoIP because packets arrive at inconsistent intervals.

NE - Network Engineer Practice Test

NE - Network Engineer Practice Test

NE NE WAN Technologies 3