Which layer of the OSI/ISO model handles physical addressing, network topology, line discipline, error notification, orderly delivery of frames, and…

The Data Link layer (Layer 2) of the OSI model is responsible for the reliable transfer of data frames between adjacent nodes on a network segment. It is divided into two sublayers: the Media Access Control (MAC) sublayer and the Logical Link Control (LLC) sublayer. The MAC sublayer handles physical addressing (MAC addresses), network topology, and line discipline (controlling access to the medium). The LLC sublayer is responsible for error notification (typically through a Frame Check Sequence), orderly delivery of frames, and optional flow control to prevent a fast sender from overwhelming a slow receiver. All functions listed in the question are core responsibilities of the Data Link layer.

A. Physical: This layer is concerned with the transmission of raw bits over a physical medium, defining electrical and mechanical specifications, not addressing or frame control.

C. Network: This layer handles logical addressing (e.g., IP addresses) and routing of packets across different networks, not physical addressing on a local link.

D. Session: This layer establishes, manages, and terminates communication sessions between applications, a function far removed from hardware-level addressing and frame delivery.

1. ISO/IEC 7498-1:1994

Information technology — Open Systems Interconnection — Basic Reference Model: The Basic Model. Section 7.6

"The Data-Link Layer

" details the layer's functions

including providing data-link-connections

error detection

and flow control (Clauses 7.6.3.4 and 7.6.3.5).

2. Kurose

J. F.

& Ross

K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. In Chapter 6

"The Link Layer and LANs

" Section 6.1 introduces the services of the link layer

explicitly mentioning framing

link access (line discipline)

flow control

and error detection. Section 6.3 is dedicated to MAC addresses (physical addressing).

3. Stallings

W. (2014). Data and Computer Communications (10th ed.). Pearson. Chapter 3

"Data Link Control Protocols

" Section 3.2

"Flow Control" and Section 3.3

"Error Control

" describe these core functions of the Data Link layer. The role of physical addressing is detailed in the context of LANs in subsequent chapters.