Modern Networking - Unit 1 Answers (MSc IT Level)

Q1. The Networking Ecosystem (Already provided in previous message with diagram)

Q2. Ethernet and Its Applications (Already provided in previous message)

Q3. Wi-Fi and Its Applications Wi-Fi is a wireless networking technology (IEEE 802.11) that enables devices
to communicate without physical cables using radio frequencies (2.4 GHz and 5 GHz).

Applications:

• Home and office wireless internet

• Mobile device connectivity
• Smart home/IoT networks
• Campus or enterprise access points
• Public Wi-Fi hotspots

Advantages: Easy to install, mobility, supports multiple devices. Limitations: Security issues, signal
interference, limited range.

Q4. Wi-Fi Standards and Data Rates

Standard Frequency Max Speed Key Features

802.11b 2.4 GHz 11 Mbps Legacy support

802.11g 2.4 GHz 54 Mbps Faster and backward compatible

802.11n 2.4/5 GHz 600 Mbps MIMO support

802.11ac 5 GHz 1.3 Gbps Beamforming, faster speed

802.11ax (Wi-Fi 6) 2.4/5/6 GHz 10 Gbps OFDMA, high efficiency

Q5. 4G/5G Cellular Technology

• 4G (LTE): IP-based network using OFDMA, supports up to 1 Gbps download.

• 5G: Ultra-low latency (<1ms), >10 Gbps speed, supports massive IoT, edge computing, and smart
cities.

Use Cases: Real-time video, IoT, self-driving cars, AR/VR.

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Q6. Characteristics of Cloud Computing

• On-demand self-service
• Broad network access
• Resource pooling
• Rapid elasticity
• Measured service (pay-as-you-go)

Q7. Benefits of Cloud Computing

• Cost efficiency
• Scalability
• Accessibility
• Disaster recovery
• Improved collaboration
• Automatic updates

Q8. Cloud Networking and Cloud Storage

• Cloud Networking: Virtual networking over the internet using cloud infrastructure (e.g., AWS VPC).
• Cloud Storage: Online storage services like Google Drive, OneDrive using distributed file systems.

Q9. Internet of Things (IoT) and Its Evolution IoT refers to interconnecting physical devices over the
internet to collect and exchange data.

• Evolution: From RFID and sensors → Wireless sensor networks → Smart homes/cities → Industrial
IoT

Q10. Layers of IoT

1. Perception Layer: Sensors and data collection

2. Network Layer: Transmits data (Wi-Fi, LTE, Zigbee)
3. Middleware Layer: Data processing, analytics
4. Application Layer: End-user services (e.g., smart home, healthcare)

Q11. Network Convergence Integration of voice, video, and data into a single network infrastructure.
Example: IP-based telephony and video calls on the same enterprise network.

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Q12. Unified Communication and Architecture Unified Communication integrates real-time and non-real-
time communication services (VoIP, chat, email, conferencing).

• Architecture: Presence servers, gateways, session border controllers, integrated apps like MS
Teams.

Q13. Types of Networks and Internet Traffic

• Networks: LAN, WAN, PAN, MAN, CAN

• Internet Traffic Types: Web traffic, email, VoIP, video streaming, P2P traffic

Q14. Big Data Large, complex datasets that traditional systems can't handle. Characterized by 5 Vs: Volume,
Velocity, Variety, Veracity, Value.

Q15. Cloud Computing Delivery of computing services (storage, servers, databases) over the internet with
flexible, scalable models (IaaS, PaaS, SaaS).

Q16. Mobile Traffic Data transferred over mobile networks (e.g., 4G/5G). Includes video, app usage,
messaging. Managed by mobile service providers using traffic shaping and QoS.

Q17. QoS and QoE

• QoS (Quality of Service): Technical metrics like latency, jitter, bandwidth.

• QoE (Quality of Experience): User-perceived service quality based on application behavior and
satisfaction.

Q18. Characteristics of Routing

• Path determination
• Packet forwarding
• Loop avoidance
• Scalability
• Convergence
• Policy-based routing

Q19. Congestion Control and Effects Techniques used to manage excessive data traffic that can degrade
network performance. Effects include packet loss, delay, and throughput drop.

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Q20. Congestion Control Techniques

• TCP Congestion Control (AIMD)

• Queue Management (RED)
• Traffic Shaping
• Load balancing
• Rate limiting

Q21. Network Hierarchy

• Access Network: Connects end devices to ISP (e.g., Wi-Fi, Ethernet)

• Distribution Network: Aggregates traffic from access networks (e.g., layer 3 switches)
• Core Network: High-speed backbone connecting major nodes and data centers

Q22. Elastic, Inelastic, and Real-time Traffic

• Elastic: Tolerates delay (e.g., email)

• Inelastic: Sensitive to delay/loss (e.g., video streaming)
• Real-time: Requires constant transmission (e.g., VoIP, live video conferencing)

continue

give ansers of questions from 23 to 139

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Modern Networking - Unit 2 to 5 Answers (Q23 to Q139)

Q23. Define Software-Defined Networking (SDN) and Explain its Functionality SDN separates the
control plane (decision-making) from the data plane (forwarding). A central controller manages the network
dynamically using APIs. This improves agility, scalability, and automation.

Q24. Network Functions Virtualization (NFV) NFV virtualizes traditional network functions (e.g., firewall,
router) to run on general-purpose hardware. It improves flexibility, reduces cost, and supports dynamic
scaling.

Q25. Modern Networking Elements - SDN Controllers - Virtual Network Functions (VNFs) - OpenFlow
Switches - Virtual Routers/Firewalls - Cloud Networking Interfaces

Q26. SDN Approach - Centralized controller - Programmable network behavior - Open APIs (e.g., OpenFlow)
- Decoupled control and data planes

Q27. SDN Architecture (with Diagram) 1. Application Plane – Defines network apps 2. Control Plane –
Centralized SDN controller 3. Data Plane – Network devices (switches/routers)

Diagram: App Layer ↔ Controller ↔ Switches

Q28. Characteristics of SDN - Centralized control - Programmability - Dynamic resource allocation - Vendor
neutrality - Simplified network management

Q29. SDN Data Plane (with Diagram) Contains forwarding devices (OpenFlow switches) that match,
modify, and forward packets based on rules from the controller.

Q30. OpenFlow Logical Network Device Defines flow tables, matching fields, counters, actions (forward,
drop, etc.).

Q31. OpenFlow Protocol A standard protocol between the SDN controller and switches to install flow rules,
retrieve statistics, and manage network behavior.

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Q32. SDN Control Plane Architecture Provides centralized intelligence via controllers, communicates with
apps (northbound) and switches (southbound).

Q33. ITU-T Model (with Diagram) Includes service plane, control plane, and data plane – focusing on QoS,
resource management, and service orchestration.

Q34. OpenDaylight Architecture A modular SDN controller platform supporting plugins, APIs, and tools
for managing networks.

Q35. Border Gateway Protocol (BGP) An interdomain routing protocol used to exchange routing info
between autonomous systems on the internet.

Q36. Routing and QoS Between Domains Involves policy-based routing and QoS enforcement using BGP
extensions or RSVP for service-level agreements.

Q37. BGP for QoS Management Uses BGP FlowSpec to define and advertise traffic flow rules that can
enforce QoS policies across domains.

Q38. SDN Application Plane Architecture Consists of software apps (e.g., routing, firewall, load balancer)
that interact with the controller to define network behavior.

Q39. Network Services Abstraction Layer It acts as a middleware between SDN controller and
applications, abstracting physical network complexities.

Q40. Traffic Engineering Optimizing data flow paths for performance, reliability, and load balancing across
a network using tools like MPLS.

Q41. Data Center Networking High-speed, low-latency architecture using spine-leaf topology, SDN,
virtualization, and automation tools.

Q42. Cloud Networking over SDN Uses SDN to dynamically manage cloud network infrastructure, improve
agility, and provide secure multitenancy.

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Q43. Information-Centric Networking (ICN) Focuses on content instead of host IPs. Data is cached in the
network, improving efficiency and performance.

Q44. Mobility and Wireless Covers handover techniques, mobile IP, seamless connectivity across Wi-Fi, 4G/
5G in SDN-enabled networks.

Q45. OpenDaylight Helium A release of OpenDaylight platform with better modularity, OSGi framework,
and enhanced SDN features.

Q46. Representational State Transfer (REST) An architectural style for APIs. Uses HTTP methods (GET,
POST, PUT, DELETE) and stateless communication.

Q47. Centralized vs Distributed Controllers - Centralized: Single point of control (simple but risky). -
Distributed: Multiple controllers (scalable, fault-tolerant).

Q48. High-Availability Clusters Redundant nodes that take over if one fails. Used in controllers and data
centers for fault tolerance.

Q49. Federated SDN Networks Multiple SDN domains collaborating via inter-controller communication to
manage global policies.

Q50. Traffic Engineering (Repeated – see Q40)

Q51. Flow Table Structure Contains match fields, counters, and actions. Rules define how packets are
processed in OpenFlow switches.

Q52. Port Types in OpenFlow Switch - Physical Port - Logical Port - Reserved Port

Q53. Group Table Allows multiple actions (e.g., broadcast, multicast). Supports load balancing and fast
failover.

Q54. Frenetic Architecture A high-level language and runtime for programming SDN policies. Focuses on
correctness and modularity.

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Q55. Policy Cop SDN Application An SDN app for traffic engineering. Monitors, detects policy violations,
and enforces rules.

Q56. Diagram of SDN Architecture & Characteristics (See Q27 + Q28)

Q57. SDN Control Plane Architecture and Functions Same as Q32. Functions: Routing decisions, load
balancing, network policy enforcement.

Q58. CCNX (Content-Centric Networking) A protocol focusing on content rather than location. Uses
named data and content caching.

Q59. Cloud Network as a Service (Cloud NaaS) Provides virtual network services (VPN, firewalls) on
demand. Steps: Request → Provision → Configure → Monitor.

Q60. OpenDaylight DDoS Application Monitors traffic for anomalies, detects attacks, applies mitigation
strategies like rate-limiting or rerouting.

Q61. Six REST Constraints and Example 1. Client-server 2. Stateless 3. Cacheable 4. Uniform interface 5.
Layered system 6. Code on demand (optional) Example: GET /api/devices

Q62. ITU-T Y.3300 SDN Model Defines layered SDN architecture with service, control, and forwarding
layers. Focus on interoperability and standardization.

Q63. Routing Function in SDN Controller Determines optimal paths, installs flow rules, adapts dynamically
to topology changes.

Q64. SDN Definition and Functionality (Repeat of Q23)

Q65. Evolving Network Requirements - Scalability - Virtualization - Security - Multi-tenancy - Real-time

control

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Q66. SDN Abstractions - Forwarding Abstraction: Abstracts data forwarding - Distribution Abstraction:
Centralized decision-making - Specification Abstraction: High-level network behavior definition

Q67. Centralized vs Distributed Controller Architecture Same as Q47.

Q68–Q139: NFV, Virtualization, QoS/QoE, IoT, Cloud & Security (Will continue in next response...)

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Modern Networking - Unit 2 to 5 Answers (Q23 to Q139)

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Q65. Evolving Network Requirements Modern networks need to support: - High scalability and flexibility -
Automation and programmability - Multi-tenancy support - Security, privacy, and compliance - Integration
with cloud and IoT - Dynamic load handling and fault tolerance

Q66. SDN Abstractions - Forwarding Abstraction: Interface between SDN controller and data plane. -
Distribution Abstraction: Enables the distribution of network state. - Specification Abstraction: Allows
app developers to express desired network behavior.

Q67. Centralized vs Distributed SDN Controller Architecture - Centralized: Simpler to manage but
creates a single point of failure. - Distributed: Provides better fault tolerance and scalability; controllers
sync state.

Q68. Virtual Machines Software emulations of physical computers that run guest OS and applications in
isolation using hypervisors.

Q69. Function of NFV NFV virtualizes network functions like firewalls and load balancers. It enables
dynamic provisioning and reduces dependency on hardware.

Q70. Principles of NFV - Decouple hardware and software - Support dynamic resource allocation - Use of
standard virtualization techniques

Q71. High-Level NFV Framework Consists of VNFs, NFVI (infrastructure), and MANO (Management and
Orchestration) components.

Q72. Benefits and Requirements of NFV Benefits: Flexibility, cost reduction, scalability, and innovation.
Requirements: High-performance virtualization, security, management, and orchestration.

Q73. NFV Reference Architecture Divided into: - VNF Layer - NFVI Layer (Compute, Storage, Networking) -
MANO Layer

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Q74. NFV Management and Orchestration MANO handles lifecycle management, VNF deployment, fault
handling, and resource orchestration.

Q75. NFV Infrastructure (NFVI) Hardware and software environment where VNFs run. Includes compute
nodes, virtual switches, and storage systems.

Q76. Logical Structure of NFVI Domains Includes multiple domains like compute domain, hypervisors,
network domain, and storage domain working together.

Q77. NFVI Implementation Using Compute Domain Nodes Deploy VNFs on virtual machines or
containers managed by hypervisors over physical compute servers.

Q78. Virtual Networks – L2 vs L3 - L2: Uses MAC addressing; supports VLANs. - L3: Uses IP addressing;
supports routing and segmentation.

Q79. Virtualized Network Functions (VNFs) Software-based network functions like virtual firewall, router,
NAT, IDS that run over virtualized infrastructure.

Q80. Different VNF Interfaces - Management Interface - Internal Interface (VNF-to-VNF) - External
Interface (to users/networks)

Q81. VNFC to VNFC Communication Intra-VNF components communicate via internal virtual links to
provide composite network services.

Q82. Functions of Virtual Network Function Manager (VNFM) Manages VNF lifecycle (instantiation,
scaling, updating, termination), monitoring, and configuration.

Q83. NFV Use Cases - Virtual CPE - vFirewall - Virtual EPC - Content Delivery Networks - Load Balancers

Q84. Virtual LANs and Uses A VLAN allows logical segmentation of networks within the same physical
switch. Used for security and traffic management.

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Q85. OpenFlow VLAN Support Supports VLAN tagging/untagging actions and matching fields to identify
traffic for specific VLANs.

Q86. MPLS VPNs Multi-Protocol Label Switching enables VPNs by directing data from one node to another
based on short path labels.

Q87. OpenDaylight’s Virtual Tenant Network An SDN application for multitenant network virtualization
using VXLANs, policy enforcement, and network segmentation.

Q88. SDI Architecture Software Defined Infrastructure enables infrastructure automation for compute,
network, and storage via APIs.

Q89. Software-Defined Storage Architecture Separates storage control logic from physical hardware to
enable flexible, scalable, and programmable storage management.

Q90. Virtual Private Networks (VPNs) Extend private networks over public internet securely using
tunneling protocols (e.g., IPsec, PPTP, L2TP).

Q91. IEEE 802.1Q VLAN Standard Defines a method to tag Ethernet frames with VLAN information for
identifying and segmenting traffic.

Q92. OSS/BSS - OSS (Operations Support System): Handles network monitoring, configuration, fault
management. - BSS (Business Support System): Manages billing, user accounts, and customer services.

Q93. Element Management Involves managing individual network elements (like routers/switches)
through a dedicated system (EMS).

Q94. Concept of NFV (Repeat of Q24/Q69): Virtualizes network functions using software and commodity
hardware.

Q95. ITU-T QoS Architectural Framework Defines QoS mechanisms across multiple layers and entities for
end-to-end service performance.

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Q96. QoS Architectural Framework Includes traffic classification, admission control, scheduling, policing,
shaping, and performance monitoring.

Q97. Integrated Services Architecture Supports per-flow QoS using RSVP (Resource Reservation Protocol)
to reserve bandwidth.

Q98. Differentiated Services Uses DSCP bits in IP headers to assign priority levels to packets for scalable
QoS.

Q99. Service Level Agreements (SLAs) Contracts between provider and customer that define expected
QoS metrics and penalties.

Q100. QoE/QoS Layered Model Layers: - User - Application - Service - Network Each layer contributes to
user-perceived experience.

Q101. IP Performance Metrics Latency, jitter, packet loss, throughput, and availability — used to measure
QoS.

Q102. Motivations for QoE Ensuring user satisfaction, service quality assurance, competitive
differentiation.

Q103. Factors Influencing QoE Device capability, network conditions, application performance, and user
expectations.

Q104. Queuing Discipline Methods to manage packet scheduling in routers (e.g., FIFO, WFQ, RED).

Q105. OpenFlow QoS Support OpenFlow supports queue assignment, rate limiting, and flow-based QoS
management.

Q106. QoE Measurement Techniques - Subjective surveys - Objective metrics (PSNR, MOS) - Passive/active
network probing

Q107. Applications of QoE Video streaming, VoIP, online gaming, telemedicine, remote learning.

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Q108. QoE/QoS Mapping Models Models to correlate QoS parameters with user-experience (e.g., E-model
for VoIP).

Q109. Network Layer QoE/QoS Mapping for Video Uses buffering, bitrate, and loss metrics to assess
streaming quality and adjust flow.

Q110. Actionable QoE Over IP Networks Systems that monitor QoE and trigger real-time network
adjustments (e.g., rerouting, prioritization).

Q111. Monitoring and Classification Active vs passive monitoring. Classifies traffic for policy enforcement,
performance tracking.

Q112. QoS Monitoring Solutions SNMP, NetFlow, sFlow, active probes to monitor network performance
and enforce SLAs.

Q113. QoE Monitoring Solutions Use of DPI, analytics platforms, synthetic testing tools to assess end-user
experience.

Q114. QoE-Based Network and Service Management Uses QoE feedback to guide network resource
allocation and fault response.

Q115. QoE-Based VoIP Call Management Monitors call metrics (jitter, MOS) to manage call quality
dynamically.

Q116. QoE-Based Host-Centric Handover User device decides network switch based on perceived
experience.

Q117. QoE-Based Network-Centric Handover Network infrastructure monitors QoE and triggers handover
automatically.

Q118. Integrated Services for Congestion Management RSVP reserves resources for specific flows to
manage congestion proactively.

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Q119. SDN Data Plane Functions Forwarding, filtering, metering, queueing, and executing controller-
defined actions.

Q120. Virtual LAN (VLAN) A logical segmentation of networks within a switch, improves security and traffic
control.

Q121. Type 1 vs Type 2 Hypervisors - Type 1: Bare-metal (e.g., VMware ESXi) – better performance - Type
2: Hosted (e.g., VirtualBox) – runs on OS

Q122. L2 vs L3 Virtual Networks - L2: Works on MAC addresses (e.g., VLANs) - L3: Works on IP addressing
and routing

Q123. QoE Influencing Factors Same as Q103

Q124–Q139: IoT & Cloud (Will continue in next update...)

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Modern Networking - Unit 2 to 5 Answers (Q23 to Q139)

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Q124. Scope of Internet of Things (IoT) IoT enables devices to collect and exchange data across diverse
sectors including smart homes, industrial automation, agriculture, healthcare, and smart cities.

Q125. Five Principal Components of IoT-Enabled Things 1. Sensors/Actuators – Data collection and
control 2. Connectivity – Network interface (Wi-Fi, Zigbee, 5G) 3. Data Processing – Embedded processors
or cloud systems 4. Software – Device firmware and applications 5. User Interface – Mobile/web interfaces
for control and visualization

Q126. ITU-T vs IoT World Forum IoT Reference Models - ITU-T Model: Focuses on layered architecture
(perception, network, service, application) - IoT World Forum Model: 7-layer model including devices,
network, data, processing, applications, business, and security

Q127. IoTivity (Open Source Implementation) An open-source IoT framework by the Open Connectivity
Foundation (OCF) supporting interoperability across devices using RESTful APIs.

Q128. ioBridge (Commercial Implementation) Provides cloud-based hardware and services for IoT
automation. Used in smart homes and industrial control systems with web-based dashboards.

Q129. Short Notes - a. Sensors: Devices that detect physical properties (e.g., temperature, pressure) and
convert them to signals. - b. RFID: Radio-frequency identification for object tracking using tags and readers.
- c. ITU-T IoT Model: Layered model focusing on service abstraction. - d. IoT World Forum Model:
Business-centric model covering device to business layer. - e. Fog Computing: Extends cloud computing to
the edge, reducing latency and bandwidth use. - f. Cisco IoT System: A framework integrating security,
management, and analytics for IoT deployments. - g. ThingSpeak: An IoT analytics platform for data
collection, storage, visualization, and triggering actions.

Q130. Elements of Cloud Computing - Compute resources (VMs, containers) - Storage systems -
Networking - Service management and orchestration - User interfaces and APIs

Q131. Cloud Service Models - IaaS: Infrastructure as a Service (e.g., AWS EC2) - PaaS: Platform as a Service
(e.g., Google App Engine) - SaaS: Software as a Service (e.g., Gmail, Office 365)

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Q132. Cloud Deployment Models - Public Cloud: Available to general public (e.g., AWS) - Private Cloud:
Dedicated for a single organization - Hybrid Cloud: Combines public and private - Community Cloud:
Shared by several organizations

Q133. NIST Cloud Computing Reference Architecture Defines five actors: - Cloud Provider - Cloud
Consumer - Cloud Auditor - Cloud Broker - Cloud Carrier Focuses on service models and security.

Q134. ITU-T Cloud Computing Functional Reference Architecture Comprises infrastructure, resource,
and service layers with focus on QoS, resource pooling, and virtualization.

Q135. Compare NIST vs ITU-T Architectures - NIST: Role-based, security-focused - ITU-T: Function-based,
service and resource centric

Q136. Relevance of SDN and NFV to Cloud Computing - SDN: Enables flexible, programmable network
management - NFV: Reduces hardware dependency; enables virtualized services Together they enhance
agility, cost-efficiency, and scalability of cloud services.

Q137. Threats Related to SDN - Centralized controller becomes a single point of failure - API abuse or
insecure communication - Malicious or misbehaving applications - Lack of standardized security models

Q138. Short Notes - i) Sensors: Devices that collect physical data - ii) RFID: Wireless data transmission
using electromagnetic fields - iii) IoTivity: Open standard for device-to-device communication - iv)
ioBridge: Cloud-connected modules for real-time control

Q139. Security Requirements - Confidentiality: Prevent unauthorized access - Integrity: Ensure data is
not altered - Availability: Ensure uptime and responsiveness - Authentication & Authorization: Verify
identity and permissions - Auditability: Log and track access/actions

End of Answers Q23 to Q139 ✅