Questions: Question 1 Which layer of the OSI model defines functions related to data delivery, error recovery, and flow control? Application Presentation Session Transport Network Data link Physical Question 2 Which part of the Ethernet address is assigned to vendors to identify the equipment manufactured by them? First two bytes Last byte First three bytes Last three bytes Second and third bytes

The answer is the Transport layer.

Explanation for each option:

• Application: This layer is responsible for providing network services directly to the user's applications. It does not handle data delivery, error recovery, or flow control.
• Presentation: This layer is responsible for translating data between the application layer and the network format. It deals with data encryption, compression, and translation, not with data delivery, error recovery, or flow control.
• Session: This layer manages sessions between applications. It establishes, manages, and terminates connections but does not handle data delivery, error recovery, or flow control.
• Transport: This layer is responsible for data delivery, error recovery, and flow control. It ensures that data is delivered error-free, in sequence, and with no losses or duplications.
• Network: This layer is responsible for routing, forwarding, and addressing. It does not handle data delivery, error recovery, or flow control.
• Data link: This layer is responsible for node-to-node data transfer and error detection and correction in the physical layer. It does not handle end-to-end data delivery, error recovery, or flow control.
• Physical: This layer deals with the physical connection between devices and the transmission and reception of raw bitstreams over a physical medium. It does not handle data delivery, error recovery, or flow control.

Question 2: The answer is the first three bytes.

Explanation for each option:

• First two bytes: This is incorrect because the vendor-specific identifier is longer than two bytes.
• Last byte: This is incorrect because the vendor-specific identifier is longer than one byte.
• First three bytes: This is correct. The first three bytes of an Ethernet address (also known as the Organizationally Unique Identifier or OUI) are assigned to vendors by the IEEE to identify the equipment manufactured by them.
• Last three bytes: This is incorrect because the last three bytes are used to uniquely identify the device within the vendor's assigned range.
• Second and third bytes: This is incorrect because the vendor-specific identifier includes the first three bytes, not just the second and third.

Summary:

1. The Transport layer of the OSI model defines functions related to data delivery, error recovery, and flow control.
2. The first three bytes of the Ethernet address are assigned to vendors to identify the equipment manufactured by them.