JNTU B.Tech III COMPUTER NETWORKS Previous Question Paper (October - 2020 - R13)

The Data Link Layer is responsible for node-to-node delivery of data. Its primary design issues include:

• Framing: Breaking the bit stream received from the physical layer into manageable units called frames, including the addition of start and end delimiters to identify frame boundaries.
• Physical Addressing: Incorporating source and destination hardware addresses (MAC addresses) in the frame header to ensure delivery to the correct node on the same network.
• Flow Control: Implementing mechanisms to prevent a fast sender from overwhelming a slow receiver, typically using feedback-based or rate-based protocols.
• Error Control: Detecting and correcting errors (such as bit flips) that occur during transmission, often using techniques like Cyclic Redundancy Check (CRC) and retransmission protocols (ARQ).
• Access Control: Managing how multiple devices share a common communication channel in broadcast networks to prevent collisions and ensure fair access.

Internet standards are formal documents that define the protocols, procedures, and conventions used for communication across the global Internet. These are managed primarily by the Internet Engineering Task Force (IETF).

Key aspects include:

• RFCs (Request for Comments): The primary vehicle for Internet standards. Not all RFCs are standards; they progress through a maturity process starting as an Internet Draft, moving to Proposed Standard, then Internet Standard (STD).
• Openness: Standards are developed through an open, consensus-based process, ensuring interoperability between hardware and software from different vendors.
• IAB (Internet Architecture Board): Provides oversight and guidance for the architectural evolution of the Internet and manages the liaison with other standards bodies.
• IANA (Internet Assigned Numbers Authority): Responsible for the global coordination of IP addresses, domain names, and protocol parameters, ensuring unique identification across the network.