TMP Network Design & Optimization 4 — Questions and Answers
Question 1: Which network capacity planning model uses historical traffic growth trends to forecast future bandwidth requirements?
- Erlang B formula
- Time-series trend analysis (Correct answer)
- M/M/1 queuing model
- Binomial traffic model
Correct answer: Time-series trend analysis
Time-series trend analysis extrapolates historical utilization data to project when network links will require capacity upgrades.
Question 2: A TMP professional needs to design a network with 99.999% availability (five-nines). Which strategy MOST directly achieves this?
- Using the highest-grade hardware available
- Eliminating all single points of failure through redundant paths and components (Correct answer)
- Deploying a centralized management platform
- Maximizing link utilization efficiency
Correct answer: Eliminating all single points of failure through redundant paths and components
Five-nines availability requires eliminating single points of failure at every layer — hardware, links, power, and software — so any single failure does not cause an outage.
Question 3: In MPLS networks, what is the function of a Label Edge Router (LER)?
- Forwards packets based solely on IP routing tables
- Imposes or removes MPLS labels at the edge of the MPLS domain (Correct answer)
- Manages label distribution between core LSRs
- Acts as the BGP route reflector for the MPLS core
Correct answer: Imposes or removes MPLS labels at the edge of the MPLS domain
The LER (also called PE router) adds MPLS labels to incoming IP packets at the ingress edge and removes them at the egress edge.
Question 4: Which approach to network design allows traffic engineering by explicitly specifying the path packets take through the network?
- Policy-based routing (PBR) (Correct answer)
- Default route propagation
- Dynamic host configuration
- Equal-cost load balancing
Correct answer: Policy-based routing (PBR)
PBR allows administrators to override normal routing decisions and direct traffic along specific paths based on defined policies.
Question 5: During a network optimization project, a manager discovers that 60% of WAN traffic is Netflix video. Which solution BEST reduces WAN utilization?
- Increase WAN link speed by 60%
- Implement split tunneling or local internet breakout for non-business traffic (Correct answer)
- Deploy additional MPLS circuits
- Enable OSPF load balancing
Correct answer: Implement split tunneling or local internet breakout for non-business traffic
Local internet breakout (split tunneling) routes consumer internet traffic directly to the internet at the branch rather than backhauling it over the corporate WAN.
Question 6: What does Mean Time to Repair (MTTR) measure in telecommunications network management?
- Average time between network failures
- Average time to restore service after a failure occurs (Correct answer)
- Total downtime as a percentage of uptime
- Time required to provision new network capacity
Correct answer: Average time to restore service after a failure occurs
MTTR is the average duration from the onset of a failure to full service restoration, a key metric for evaluating operational efficiency.
Question 7: A network engineer is evaluating two routing designs. Design A uses OSPF areas to reduce LSA flooding. Design B uses flat OSPF with no areas. Which statement is correct?
- Design B scales better because routing tables are smaller
- Design A scales better because area boundaries limit LSA propagation and SPF recalculation scope (Correct answer)
- Design A requires more router CPU for SPF calculations
- Design B provides faster convergence in all scenarios
Correct answer: Design A scales better because area boundaries limit LSA propagation and SPF recalculation scope
OSPF areas contain LSA flooding and limit SPF recalculations to within each area, dramatically improving scalability in large networks.
TMP Network Design & Optimization 4
Which network capacity planning model uses historical traffic growth trends to forecast future bandwidth requirements?