CompTIA Updated N10-009 Exam Questions and Answers by catherine

An SFP (Small Form-factor Pluggable) transceiver is a modular device that provides the interface between fiber-optic or copper cabling and the networking equipment (e.g., switch or router). It operates primarily at Layer 2 (Data Link), converting optical or electrical signals into frames usable by the network device.

A. SC is a fiber connector type, not the transceiver.

B. DAC (Direct Attach Copper) is a passive copper cable assembly with fixed transceivers, not a general-purpose module.

D. Twinaxial cable is a copper medium, not an interface device.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Transceivers (SFP, GBIC, QSFP), fiber connectivity, OSI model mapping.

Introduction to Disaster Recovery Concepts:

Disaster recovery involves strategies and measures to ensure business continuity and data recovery in the event of a disaster.

Mean Time Between Failures (MTBF):

MTBF is a reliability metric used to predict the time between failures of a system during operation. It is calculated by dividing the total operational time by the number of failures.

Formula: MTBF=Total Operational TimeNumber of Failures\text{MTBF} = \frac{\text{Total Operational Time}}{\text{Number of Failures}}MTBF=Number of FailuresTotal Operational Time​

This metric helps in understanding the reliability and expected lifespan of systems and components.

Example Calculation:

If a server operates for 1000 hours and experiences 2 failures, the MTBF is: MTBF=1000 hours2=500 hours\text{MTBF} = \frac{1000 \text{ hours}}{2} = 500 \text{ hours}MTBF=21000 hours​=500 hours

Explanation of the Options:

A. MTTR (Mean Time to Repair): The average time required to repair a system after a failure.

B. MTBF (Mean Time Between Failures): The correct answer, representing the average time between failures.

C. RPO (Recovery Point Objective): The maximum acceptable amount of data loss measured in time.

D. RTO (Recovery Time Objective): The target time set for the recovery of IT and business activities after a disaster.

Conclusion:

MTBF is a crucial metric in disaster recovery and system reliability, helping organizations plan maintenance and predict system performance.

The CompTIA troubleshooting methodology includes steps like identifying the problem, establishing a theory of probable cause, testing the theory, creating a plan of action, implementing the solution, verifying functionality, and documenting findings. Establishing a theory involves analyzing the problem and considering possible causes, often by systematically checking each level of the OSI model (Physical, Data Link, Network, etc.) to pinpoint the root cause.

Why not Implement the solution? This step involves applying the fix, not analyzing the OSI model.

Why not Create a plan of action? This step focuses on planning the solution, not diagnosing the cause.

Why not Verify functionality? This step confirms the solution worked, not analyzing the OSI model.

Quality of Service (QoS) prioritizes delay-sensitive traffic such as VoIP by assigning higher priority in queues, reducing jitter, latency, and packet loss. Implementing QoS policies ensures stable and clear voice communication.

B. STP (Spanning Tree Protocol) prevents switching loops, but it does not address jitter or real-time traffic performance.

References (CompTIA Network+ N10-009):

Domain: Network Infrastructure — QoS, traffic shaping, prioritization of voice/video.