Steps in the OSI Data Encapsulation Process

CE

The Open Systems Interconnection (OSI) reference model is a conceptual framework used to describe how data moves from one computer to another on a network. The data encapsulation process is a critical part of the OSI model that ensures that data is properly packaged before being sent over the network.

The data encapsulation process includes seven layers, each of which plays a specific role in the process of moving data from one point to another. The layers are as follows:

1. Physical layer
2. Data link layer
3. Network layer
4. Transport layer
5. Session layer
6. Presentation layer
7. Application layer

Each layer in the OSI model performs a specific function, and the layers work together to ensure that data is properly packaged and transmitted across the network.

Now, let's look at the options given in the question:

A. The presentation layer translates bits into voltages for transmission across the physical link.

This statement is incorrect. The presentation layer is responsible for data formatting and conversion between different data formats, such as ASCII and EBCDIC. It does not deal with the physical transmission of data.

B. The data link layer adds physical source and destination addresses and an FCS to the segment.

This statement is correct. The data link layer is responsible for the reliable transmission of data over the physical link. It adds physical source and destination addresses to the segment and also adds a Frame Check Sequence (FCS) to ensure data integrity.

C. Packets are created when the network layer adds Layer 3 addresses and control information to a segment.

This statement is partially correct. The network layer is responsible for logical addressing and routing of data. It adds Layer 3 addresses, such as IP addresses, to the segment, but it does not add control information.

D. Packets are created when the network layer encapsulates a frame with source and destination host addresses and protocol-related control information.

This statement is incorrect. The network layer does not encapsulate a frame; it encapsulates a packet with source and destination host addresses and protocol-related control information.

E. The transport layer divides a data stream into segments and may add reliability and flow control information.

This statement is correct. The transport layer is responsible for end-to-end communication and provides reliable data transfer and flow control. It divides a data stream into segments and adds reliability and flow control information.

In summary, the two correct steps in the OSI data encapsulation process are:

• The data link layer adds physical source and destination addresses and an FCS to the segment.
• The transport layer divides a data stream into segments and may add reliability and flow control information.