A developer is writing a firmware update for an IoT device that sends telemetry data over a cellular network. The developer needs to ensure the data is transmitted reliably, so they decide to use TCP. At which layer of the OSI model does TCP operate, and what is its primary function?

Transport layer, providing end-to-end reliable delivery with acknowledgments and retransmissions.

Network layer, providing logical addressing and routing.

Application layer, providing the interface between the application and the network.

Data link layer, providing error detection on a single link.

A smart grid company is deploying sensors that communicate over a low-power wide-area network (LPWAN) using LoRaWAN. The sensors send small data packets to a gateway, which forwards them to a network server over Ethernet. The security team wants to ensure end-to-end encryption from the sensor to the network server. Which approach should they take?

Use TLS on the Ethernet segment between the gateway and the network server, because it protects the data end-to-end.

Use IPsec on the sensor, because it encrypts all traffic between the sensor and the network server.

Use LoRaWAN's built-in link-layer encryption, because it secures the entire path from sensor to network server.

Use application-layer encryption on the sensor payload, because it protects data from the sensor to the network server regardless of the underlying network.

A developer is debugging why a custom IoT device cannot send data to a cloud server. The device sends a UDP packet, and the developer captures the packet on the device's Ethernet interface. Which protocol headers will be present in the captured frame, in the correct order from outermost to innermost?

Ethernet header, IP header, UDP header, payload

UDP header, IP header, Ethernet header, payload

IP header, Ethernet header, UDP header, payload

Ethernet header, UDP header, IP header, payload

A network administrator is configuring a firewall for a smart office that uses IP cameras and VoIP phones. The administrator needs to allow HTTP traffic from the cameras to a management server and SIP traffic from the phones to a call manager. Which OSI layer do HTTP and SIP have in common?

Network layer, because both use IP for addressing.

Application layer, because both HTTP and SIP are application-layer protocols.

Transport layer, because both use TCP for reliable delivery.

Session layer, because both establish sessions between devices.

EC-CouncilIoT Security Essentials

Domain 1Objective 3

OSI and TCP Models ISE Practice Questions (Page 3)

Part of the IoT Fundamentals and Networking domain, which makes up ~15% of our current practice bank. EC-Council does not publish an official question count, but from its 120-minute exam (~50–80 total, ~8–12 in this domain), expect 2–3 from this objective — we provide 27 practice questions to prepare you well beyond it. (estimate)

27questions here

6free pages

6concepts

Questions 11–15

11application · easy
A developer is writing a firmware update for an IoT device that sends telemetry data over a cellular network. The developer needs to ensure the data is transmitted reliably, so they decide to use TCP. At which layer of the OSI model does TCP operate, and what is its primary function?
Select an answer first
12expert · hard
A smart grid company is deploying sensors that communicate over a low-power wide-area network (LPWAN) using LoRaWAN. The sensors send small data packets to a gateway, which forwards them to a network server over Ethernet. The security team wants to ensure end-to-end encryption from the sensor to the network server. Which approach should they take?
Select an answer first
13application · easy
A developer is debugging why a custom IoT device cannot send data to a cloud server. The device sends a UDP packet, and the developer captures the packet on the device's Ethernet interface. Which protocol headers will be present in the captured frame, in the correct order from outermost to innermost?
Select an answer first
14foundation · easy
An IoT device sends sensor data to a cloud server using MQTT over TCP/IP. At which layer of the TCP/IP model would encryption such as TLS be applied to protect the data?
Select an answer first
15application · easy
A network administrator is configuring a firewall for a smart office that uses IP cameras and VoIP phones. The administrator needs to allow HTTP traffic from the cameras to a management server and SIP traffic from the phones to a call manager. Which OSI layer do HTTP and SIP have in common?
Select an answer first

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OSI and TCP Models ISE Practice Questions (Page 3)

Questions 11–15

A developer is writing a firmware update for an IoT device that sends telemetry data over a cellular network. The developer needs to ensure the data is transmitted reliably, so they decide to use TCP. At which layer of the OSI model does TCP operate, and what is its primary function?

An IoT device sends sensor data to a cloud server using MQTT over TCP/IP. At which layer of the TCP/IP model would encryption such as TLS be applied to protect the data?

A network administrator is configuring a firewall for a smart office that uses IP cameras and VoIP phones. The administrator needs to allow HTTP traffic from the cameras to a management server and SIP traffic from the phones to a call manager. Which OSI layer do HTTP and SIP have in common?

Keep studying — IoT Fundamentals and Networking