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RAN Practice Exam
Question 1. Which of the following best describes the primary motivation for moving from a traditional RAN to a Cloud‑Native RAN? A) Reduce the number of antennas needed B) Increase hardware vendor lock‑in C) Achieve greater flexibility, scalability, and operational efficiency D) Eliminate the need for any base‑band processing Answer: C Explanation: Cloud‑Native RAN is adopted to provide flexible resource allocation, rapid scaling, and lower OPEX, which are key drivers for CSPs. Question 2. In the evolution from NFV to Cloud‑Native architectures, which limitation of NFV is most directly addressed by Cloud‑Native principles? A) Lack of support for 5G NR B) Heavy reliance on monolithic VNFs and slow scaling C) Inability to run on x86 servers D) Absence of any virtualization layer Answer: B Explanation: NFV often uses large monolithic VNFs that are difficult to scale; Cloud‑Native microservices and containers enable fine‑grained, rapid scaling. Question 3. Which CNCF project provides the container runtime that directly replaces the Docker Engine in many modern Kubernetes clusters? A) CoreDNS B) containerd
RAN Practice Exam
C) Prometheus D) Helm Answer: B Explanation: containerd is a CNCF‑graduated container runtime that offers a lightweight alternative to Docker Engine for Kubernetes. Question 4. In a 5G Cloud RAN deployment, Option 2 architecture splits the RAN functions into which three logical units? A) RU, DU, CU B) gNB‑Central, gNB‑Distributed, Core C) CU‑CP, CU‑UP, DU D) O‑RU, O‑DU, O‑CU Answer: C Explanation: Option 2 defines a split where the Centralized Unit (CU) is divided into Control Plane (CP) and User Plane (UP) functions, and the Distributed Unit (DU) handles lower‑layer processing. Question 5. Which characteristic is NOT a core principle of Cloud‑Native design? A) Immutable infrastructure B) Stateless services C) Manual configuration management D) Automation Answer: C
RAN Practice Exam
A) Functions that do not require any memory B) Services that do not retain client‑specific data between requests C) Hardware that has no moving parts D) Network slices that never change Answer: B Explanation: Stateless services store no session data locally, enabling easy scaling and recovery. Question 9. Which of the following is an open‑source service mesh commonly used with Kubernetes to provide traffic management, security, and observability? A) OpenStack B) Istio C) OpenDaylight D) ONAP Answer: B Explanation: Istio implements a service mesh layer that handles inter‑service communication, security policies, and telemetry. Question 10. The F1‑C interface in 5G primarily carries which type of traffic? A) User Plane data between CU‑UP and DU B) Control Plane signaling between CU‑CP and DU C) Fronthaul radio samples between RU and DU D) Core network session management
RAN Practice Exam
Answer: B Explanation: F1‑C transports control‑plane messages (e.g., RRC, MAC) between the Centralized Unit Control Plane and the Distributed Unit. Question 11. Which O‑RAN open interface connects the O‑DU to the O‑RU (radio unit)? A) A B) E C) O‑RAN Fronthaul (e.g., Open FH) D) O Answer: C Explanation: The O‑RAN Fronthaul interface defines the protocol (e.g., eCPRI) between the Distributed Unit and the Radio Unit. Question 12. The Near‑Real‑Time RIC (RAN Intelligent Controller) operates within what latency budget relative to the RAN? A) > 1 second B) 100 ms to 1 second C) 10 ms to 100 ms D) < 10 ms Answer: C Explanation: Near‑RT RIC must make decisions within 10 ms to 100 ms, enabling functions like scheduling and handover optimization.
RAN Practice Exam
C) Traditional HDDs D) Standard Ethernet NICs Answer: B Explanation: FPGAs provide deterministic, low‑latency processing suitable for PHY‑layer functions. Question 16. The Container‑as‑a‑Service (CaaS) abstraction primarily decouples containers from: A) The underlying network topology B) The hardware and operating system specifics C) The programming language used D) The radio frequency spectrum Answer: B Explanation: CaaS provides a uniform interface to run containers irrespective of the underlying hardware or OS. Question 17. Which of the following best describes a “Hybrid Cloud” deployment for Cloud RAN? A) All functions run on a single public cloud provider B) All functions run on private data‑center hardware only C) Some RAN functions run on edge/near‑real‑time sites while others run in central clouds D) RAN functions are split between satellite and terrestrial links Answer: C
RAN Practice Exam
Explanation: Hybrid Cloud combines edge (low‑latency) and central cloud resources to meet diverse latency and capacity needs. Question 18. Immutable Infrastructure ensures that: A) Servers are never patched after deployment B) Every change results in a new instance rather than modifying the existing one C) All data is stored in read‑only memory D) The same hardware is used for all network functions Answer: B Explanation: Immutable Infrastructure treats servers as disposable; updates are applied by deploying new instances. Question 19. Which IaC (Infrastructure as Code) tool is most commonly used to declaratively define Kubernetes resources? A) Ansible B) Terraform C) Helm D) Puppet Answer: C Explanation: Helm packages Kubernetes manifests into charts, enabling declarative deployment. Question 20. Zero‑Touch Automation in Cloud RAN primarily aims to: A) Eliminate all human operators from the network B) Automate provisioning, scaling, and healing without manual intervention
RAN Practice Exam
Explanation: Horizontal scaling adds more identical CNF instances to distribute load. Question 23. The ONAP (Open Network Automation Platform) primarily functions as which component in a Cloud RAN environment? A) Radio hardware vendor B) Service mesh controller C) End‑to‑end service orchestrator D. 5G core network function Answer: C Explanation: ONAP orchestrates network services across RAN and Core, handling provisioning, scaling, and termination. Question 24. Network slicing in 5G Cloud RAN is facilitated by which orchestration capability? A) Physical layer beamforming B) Virtual Machine migration C) Slice‑aware resource allocation and isolation D) Manual configuration of VLANs Answer: C Explanation: Orchestrators allocate compute, storage, and radio resources per slice, ensuring isolation and QoS. Question 25. Zero‑Trust security models in Cloud RAN require: A) Implicit trust for all internal traffic
RAN Practice Exam
B) Authentication and authorization for every request, regardless of source C) Only perimeter firewalls D. Static passwords for all services Answer: B Explanation: Zero‑Trust assumes no inherent trust; each communication is verified. Question 26. The Network Exposure Function (NEF) in 5G primarily provides: A) Direct radio access to user equipment B) Secure APIs for third‑party services to interact with the network C) Physical layer modulation schemes D. Core network routing tables Answer: B Explanation: NEF exposes network capabilities (e.g., QoS, location) to external applications through controlled APIs. Question 27. A “brownfield” migration strategy for Cloud RAN implies: A) Deploying a brand‑new network from scratch B) Incrementally upgrading existing RAN elements to Cloud‑Native while maintaining service continuity C) Replacing all hardware with green‑field sites D. Using only legacy VNFs Answer: B
RAN Practice Exam
A) > 100 ms B) 10 ms to 30 ms C) < 1 ms D. 500 ms Answer: B Explanation: The fronthaul latency budget for split‑RAN (e.g., functional split 7.2) is generally 10 ‑ 30 ms to meet real‑time scheduling. Question 31. In Kubernetes, which resource is used to enforce network policies that control traffic flow between Pods? A) ConfigMap B) NetworkPolicy C) ServiceAccount D. PersistentVolume Answer: B Explanation: NetworkPolicy objects define allowed ingress/egress traffic between Pods. Question 32. Which of the following is NOT a typical benefit of containerizing a CNF compared to running it as a VNF on a VM? A) Faster startup time B) Lower resource overhead C. Automatic hardware acceleration without drivers D. Better scalability
RAN Practice Exam
Answer: C Explanation: Containers still need appropriate drivers to leverage hardware acceleration; they do not automatically provide it. Question 33. The E2 interface in O‑RAN connects which two components? A) O‑DU and O‑RU B) Near‑Real‑Time RIC and O‑CU C) Near‑Real‑Time RIC and O‑DU D. O‑CU and Core Network Answer: C Explanation: E2 is the open interface between the Near‑RT RIC and the O‑DU (or O‑CU) for policy and control. Question 34. Which term best describes the practice of defining the entire infrastructure (servers, networks, storage) in version‑controlled code files? A) Manual provisioning B) Infrastructure as Code (IaC) C. Physical provisioning D. Dynamic scaling Answer: B Explanation: IaC enables reproducible, automated deployment of infrastructure using code. Question 35. A “service mesh sidecar” in Istio is primarily responsible for: A) Running the main business logic of a microservice
RAN Practice Exam
Explanation: Decoupling allows each plane to scale independently, optimizing resource usage. Question 38. Which of the following is a primary reason to use SmartNICs in Cloud RAN deployments? A) To provide additional storage capacity B) To offload network packet processing and reduce CPU load C. To replace the need for GPUs D. To increase the number of Ethernet ports only Answer: B Explanation: SmartNICs can perform packet filtering, encryption, and other networking tasks, freeing CPU cycles for baseband processing. Question 39. The term “stateless microservice” implies that the service: A) Stores session data in local memory between requests B) Persists all data in a local file system C) Relies on external databases or caches for stateful information D. Cannot be scaled horizontally Answer: C Explanation: Stateless services keep no client‑specific state locally; they retrieve needed data from external stores. Question 40. Which O‑RAN component provides the abstraction layer for managing radio resources across multiple O‑RU devices? A) O‑DU
RAN Practice Exam
B) O‑CU
C) O‑RAN Central Unit (O‑CU) D. Near‑Real‑Time RIC Answer: B Explanation: The O‑CU (central unit) handles higher‑layer radio functions and coordinates multiple O‑RUs via the O‑DU. Question 41. In Kubernetes, what is the purpose of a “Deployment” object? A) To define a network route B) To manage the lifecycle of a set of identical Pods, including rolling updates C. To store secret keys D. To allocate persistent storage Answer: B Explanation: Deployments ensure the desired number of Pods are running and support versioned rollouts. Question 42. Which of the following best describes the “edge” in Edge Computing for Cloud RAN? A) A central data‑center located far from the end‑user B) A compute node placed close to the radio site to meet low‑latency requirements C. A virtual machine in the public cloud D. A storage‑only appliance Answer: B
RAN Practice Exam
B. Distributed tracing C. Log aggregation D. Direct hardware debugging via JTAG Answer: D Explanation: Observability focuses on software‑level telemetry; JTAG is a low‑level hardware debug interface. Question 46. Which 5G core network function is directly interfaced via the N2 interface from the gNB‑CU‑CP? A) AMF (Access and Mobility Management Function) B) SMF (Session Management Function) C) UPF (User Plane Function) D. PCF (Policy Control Function) Answer: A Explanation: N2 connects the CU‑CP to the AMF for control‑plane signaling. Question 47. Which of the following best describes a “service function chain” in a Cloud‑Native RAN environment? A) A sequence of VNFs that packets traverse for processing B) A linear physical cable layout between antennas C. A set of static IP addresses for each microservice D. A hardware RAID configuration Answer: A
RAN Practice Exam
Explanation: Service function chaining defines ordered processing steps across network functions. Question 48. The “E1” interface in 5G is primarily used for: A) Connecting CU‑CP to CU‑UP within the same Centralized Unit B. Transporting user‑plane data between DU and RU C. Signaling between gNB and core network D. Connecting two Centralized Units (CU‑CP to CU‑UP) in a split architecture Answer: D Explanation: E1 links the Control Plane and User Plane parts of a Centralized Unit when they are separated. Question 49. Which of the following is a typical security measure applied at the container runtime level? A) Enabling root login inside containers B) Running containers with non‑root user IDs and read‑only file systems C. Disabling SELinux on the host D. Providing containers unrestricted network access Answer: B Explanation: Least‑privilege and immutable file systems reduce attack surface within containers. Question 50. In a Cloud‑Native RAN, the “Control‑Plane (CP) latency budget” between CU‑CP and DU is generally: A) > 100 ms
