Cisco 350-501 Practice Test 5
Question 40
For an original SPCOR service-provider engineering scenario, consider: A 5G RAN integrator treats fronthaul, midhaul and backhaul as synonyms and cannot identify where the distributed and central units connect. Select TWO complementary steps: the targeted correction and its strongest prechange validation.
- Change: Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split.
- Change: Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment.
- Route time-sensitive radio fronthaul over any oversubscribed path with no synchronization or jitter verification.
- Check: Test spoofed and valid sources, check BGP blackhole policy scope and verify MACsec session status and counters on supported links.
- Check: Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window.
Explanation
Correct Answer
A:Evidence: Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window.
E:Required intervention: Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split.
Incorrect Answers
B:Change: Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment. 5G RAN functional splits determine where RU DU and CU processing occurs; their transport interfaces have distinct capacity, timing and latency requirements.
C:Route time-sensitive radio fronthaul over any oversubscribed path with no synchronization or jitter verification. For this select two assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it. 5G RAN functional splits determine where RU DU and CU processing occurs; their transport interfaces have distinct capacity, timing and latency requirements. Use this instead: Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split. Distinguish the two approaches by checking: Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window. Applied case: A 5G RAN integrator treats fronthaul, midhaul and backhaul as synonyms and cannot identify where the distributed and central units connect.
D:Check: Test spoofed and valid sources, check BGP blackhole policy scope and verify MACsec session status and counters on supported links. 5G RAN functional splits determine where RU DU and CU processing occurs; their transport interfaces have distinct capacity, timing and latency requirements.
Question 41
A service provider network engineer is reviewing this backbone or customer-service scenario: A backbone team wants routed optical links but assumes coherent pluggables eliminate the need to evaluate optical reach and dispersion on each fiber span. A proposed shortcut is: Ignore optical attenuation and error counters because IP routing can always correct a fundamentally incompatible optical span. What should the service provider engineer recommend as the narrowly scoped correction? Select ONE best answer.
- Ignore optical attenuation and error counters because IP routing can always correct a fundamentally incompatible optical span.
- Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity.
- Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment.
- Apply source validation or ACL policy at the correct ingress, coordinate RTBH only for approved attack targets and enable link-layer encryption where required.
Explanation
Correct Answer
B:This targeted action addresses the observed service-provider control or forwarding gap without discarding necessary controls. Applied case: A backbone team wants routed optical links but assumes coherent pluggables eliminate the need to evaluate optical reach and dispersion on each fiber span.
Incorrect Answers
A:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. For this best change assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it.
C:Select and consistently implement the intended MPLS QoS tunneling model with explicit ingress classification and egress treatment. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
D:Apply source validation or ACL policy at the correct ingress, coordinate RTBH only for approved attack targets and enable link-layer encryption where required. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
Question 42
A Cisco service provider design review finds: A backbone team wants routed optical links but assumes coherent pluggables eliminate the need to evaluate optical reach and dispersion on each fiber span. The team proposes: Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity. Which engineering principle most strongly supports the recommended response? Select ONE best answer.
- Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior.
- uRPF checks source reachability, RTBH can discard selected routed traffic during attacks and MACsec protects appropriate Ethernet links; none is interchangeable.
- 5G RAN functional splits determine where RU DU and CU processing occurs; their transport interfaces have distinct capacity, timing and latency requirements.
- Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
Explanation
Correct Answer
D:Demonstrable success requires: Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored. Applied case: A backbone team wants routed optical links but assumes coherent pluggables eliminate the need to evaluate optical reach and dispersion on each fiber span.
Incorrect Answers
A:Uniform propagates QoS semantics end to end while pipe and short-pipe separate provider tunnel treatment from customer traffic with different egress behavior. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
B:URPF checks source reachability, RTBH can discard selected routed traffic during attacks and MACsec protects appropriate Ethernet links; none is interchangeable. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
C:5G RAN functional splits determine where RU DU and CU processing occurs; their transport interfaces have distinct capacity, timing and latency requirements. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
Question 43
The service provider operations team has not yet approved a change. Current evidence indicates: A backbone team wants routed optical links but assumes coherent pluggables eliminate the need to evaluate optical reach and dispersion on each fiber span. Which evidence best tests the technical diagnosis before approving a disruptive change? Select ONE best answer.
- Compare optic part and platform matrix, channel power, error metrics and line-system span data on a controlled pair of links.
- Capture customer DSCP, MPLS traffic class at ingress and transit, and egress queue or remark behavior under controlled congestion.
- Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan.
- Inspect received DSCP distributions, policer counters, class queue drops and reservation availability on a link saturation test.
Explanation
Correct Answer
A:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. Applied case: A backbone team wants routed optical links but assumes coherent pluggables eliminate the need to evaluate optical reach and dispersion on each fiber span.
Incorrect Answers
B:Capture customer DSCP, MPLS traffic class at ingress and transit, and egress queue or remark behavior under controlled congestion. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
C:Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
D:Inspect received DSCP distributions, policer counters, class queue drops and reservation availability on a link saturation test. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
Question 44
A candidate correction has been tested and the platform team requires a post-change acceptance check. Original problem: A backbone team wants routed optical links but assumes coherent pluggables eliminate the need to evaluate optical reach and dispersion on each fiber span. The carrier operations owner needs positive and negative tests showing existing customer services remain available. Which acceptance result demonstrates correct service provider forwarding and control behavior without disrupting authorized workflows? Select ONE best answer.
- Real-time traffic receives policy-compliant treatment while untrusted markings cannot starve other paid service classes.
- Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another.
- Spoofed ingress traffic is denied, authorized flows remain, blackholing stays scoped and required Ethernet links are authenticated and encrypted.
- Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored.
Explanation
Correct Answer
D:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. The result must be validated using the documented device, service or access context.
Incorrect Answers
A:Real-time traffic receives policy-compliant treatment while untrusted markings cannot starve other paid service classes. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
B:Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
C:Spoofed ingress traffic is denied, authorized flows remain, blackholing stays scoped and required Ethernet links are authenticated and encrypted. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
Question 45
An implementation sign-off request identifies the following problem: A backbone team wants routed optical links but assumes coherent pluggables eliminate the need to evaluate optical reach and dispersion on each fiber span. Which paired technical change and validation should close the implementation review? Select ONE best answer.
- Change: Select a service model matching customer connectivity and use the required MPLS forwarding and VPN control-plane mechanisms rather than treating a transport label as tenant isolation. Verify: Map each service endpoint, customer attachment, label-switched path and VPN policy against intended reachability using a two-tenant lab.
- Change: Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity. Verify: Compare optic part and platform matrix, channel power, error metrics and line-system span data on a controlled pair of links.
- Change: Apply source validation or ACL policy at the correct ingress, coordinate RTBH only for approved attack targets and enable link-layer encryption where required. Verify: Test spoofed and valid sources, check BGP blackhole policy scope and verify MACsec session status and counters on supported links.
- Change: Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split. Verify: Map RU DU CU interfaces, packet timing source, loss and delay budgets and measure behavior during a representative congestion window.
Explanation
Correct Answer
B:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. The change is successful only when: Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored.
Incorrect Answers
A:Change: Select a service model matching customer connectivity and use the required MPLS forwarding and VPN control-plane mechanisms rather than treating a transport label as tenant isolation. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
C:Change: Apply source validation or ACL policy at the correct ingress, coordinate RTBH only for approved attack targets and enable link-layer encryption where required. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
D:Change: Place each split RAN function and its xHaul link deliberately, enforcing the transport latency, timing and reliability needs for the selected functional split. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
Question 46
A service provider network engineer is reviewing this backbone or customer-service scenario: A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked. A proposed shortcut is: Ignore optical attenuation and error counters because IP routing can always correct a fundamentally incompatible optical span. What should the service provider engineer recommend as the narrowly scoped correction? Select ONE best answer.
- Establish explicit QoS trust boundaries, bounded class marking and TE reservation policies that match measured capacity and the selected bandwidth model.
- Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity.
- Select a service model matching customer connectivity and use the required MPLS forwarding and VPN control-plane mechanisms rather than treating a transport label as tenant isolation.
- Ignore optical attenuation and error counters because IP routing can always correct a fundamentally incompatible optical span.
Explanation
Correct Answer
B:This targeted action addresses the observed service-provider control or forwarding gap without discarding necessary controls. Applied case: A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked.
Incorrect Answers
A:Establish explicit QoS trust boundaries, bounded class marking and TE reservation policies that match measured capacity and the selected bandwidth model. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
C:Select a service model matching customer connectivity and use the required MPLS forwarding and VPN control-plane mechanisms rather than treating a transport label as tenant isolation. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
D:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. Applied case: A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked.
Question 47
A Cisco service provider design review finds: A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked. The team proposes: Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity. Which engineering principle most strongly supports the recommended response? Select ONE best answer.
- Service provider QoS must enforce customer trust and admission limits; DS-TE reservation models affect how traffic-class bandwidth can be shared or protected.
- Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
- Metro Ethernet connectivity models define endpoint relationships, while an MPLS transport label steers packets and customer isolation requires a separate service and routing design.
- IOS XE and IOS XR have distinct software architectures and management workflows; IOS XR supports a transactional configuration commit model.
Explanation
Correct Answer
B:Demonstrable success requires: Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored. Applied case: A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked.
Incorrect Answers
A:Service provider QoS must enforce customer trust and admission limits; DS-TE reservation models affect how traffic-class bandwidth can be shared or protected. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
C:Metro Ethernet connectivity models define endpoint relationships, while an MPLS transport label steers packets and customer isolation requires a separate service and routing design. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
D:IOS XE and IOS XR have distinct software architectures and management workflows; IOS XR supports a transactional configuration commit model. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
Question 48
The service provider operations team has not yet approved a change. Current evidence indicates: A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked. Which evidence best tests the technical diagnosis before approving a disruptive change? Select ONE best answer.
- Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan.
- Compare optic part and platform matrix, channel power, error metrics and line-system span data on a controlled pair of links.
- Map each service endpoint, customer attachment, label-switched path and VPN policy against intended reachability using a two-tenant lab.
- Inspect received DSCP distributions, policer counters, class queue drops and reservation availability on a link saturation test.
Explanation
Correct Answer
B:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. Confirm afterward that: Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored.
Incorrect Answers
A:Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan. A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked.
C:Map each service endpoint, customer attachment, label-switched path and VPN policy against intended reachability using a two-tenant lab. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
D:Inspect received DSCP distributions, policer counters, class queue drops and reservation availability on a link saturation test. A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked.
Question 49
A candidate correction has been tested and the platform team requires a post-change acceptance check. Original problem: A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked. The carrier operations owner needs positive and negative tests showing existing customer services remain available. Which acceptance result demonstrates correct service provider forwarding and control behavior without disrupting authorized workflows? Select ONE best answer.
- Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another.
- Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored.
- Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state.
- The virtualized network function meets service capacity and isolation objectives under peak traffic and controlled node failure.
Explanation
Correct Answer
B:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. The approved implementation step was: Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity.
Incorrect Answers
A:Marking and scheduling follow the selected model without unintended exposure of one customer's QoS assumptions to another. A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked.
C:Changes are accepted only through supported platform mechanisms and an invalid candidate does not silently alter unrelated service state. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
D:The virtualized network function meets service capacity and isolation objectives under peak traffic and controlled node failure. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
Question 50
For an original SPCOR service-provider engineering scenario, consider: A metro router interface remains down after optics migration because transceiver support, modulation mode and line-system compatibility were never checked. Select TWO complementary steps: the targeted correction and its strongest prechange validation.
- Check: Compare optic part and platform matrix, channel power, error metrics and line-system span data on a controlled pair of links.
- Ignore optical attenuation and error counters because IP routing can always correct a fundamentally incompatible optical span.
- Check: Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan.
- Change: Validate coherent optic capabilities, router support, fiber reach and link optical telemetry before enabling routed optical connectivity.
- Change: Define the selected SR data plane and explicit policy segments, then verify headend steering, supported SIDs and actual egress path.
Explanation
Correct Answer
A:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. Acceptance: Routed optical ports establish stable links within their documented performance limits and exposed errors are monitored.
D:Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation. Evidence: Compare optic part and platform matrix, channel power, error metrics and line-system span data on a controlled pair of links.
Incorrect Answers
B:For this select two assessment, the shortcut changes or bypasses the necessary routing, service or operational boundary rather than correcting it. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
C:Check: Review span attenuation, termination equipment, optical power budget, splitter ratio and supported service rates in a documented link plan. Routed optical architectures integrate packet routing and optical transport interfaces but physical-layer impairments and equipment compatibility still constrain operation.
E:This option addresses a different service provider engineering topic (Segment routing architecture SRTE and SRv6) rather than the documented Routed optical network and pluggable coherent transport decision.
