CCP TCP/IP & OSI Model Layers 2

Question 1

Which OSI layer is responsible for end-to-end error detection and flow control between two hosts?

Accepted Answer

Transport layer

Answer

The Transport layer (Layer 4) provides end-to-end error detection, flow control, and reliable data delivery between hosts.

Question 2

In the TCP three-way handshake, what is the correct sequence of messages?

Accepted Answer

SYN, SYN-ACK, ACK

Answer

The TCP three-way handshake follows SYN → SYN-ACK → ACK to establish a reliable connection.

Question 3

What does the TTL field in an IP packet header primarily control?

Accepted Answer

Maximum number of router hops before discard

Answer

TTL (Time To Live) is decremented by each router; when it reaches zero the packet is discarded, preventing infinite routing loops.

Question 4

Which TCP/IP layer corresponds to both the OSI Data Link and Physical layers?

Accepted Answer

Network Access layer

Answer

The TCP/IP Network Access (Link) layer encompasses the functions of both the OSI Physical and Data Link layers.

Question 5

A router operates at which OSI layer to make forwarding decisions?

Accepted Answer

Layer 3 – Network

Answer

Routers operate at Layer 3 (Network) and use IP addresses in packet headers to make forwarding decisions.

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