Jawaharlal Nehru Technological University Hyderabad MCA COMPUTER NETWORKS Previous Question Paper (December - 2019 - R15)

The design issues of the Data Link Layer include:

• Framing: Breaking the bit stream received from the physical layer into discrete frames for processing.
• Error Control: Detecting and correcting errors that occur during transmission, typically using checksums or cyclic redundancy checks (CRC).
• Flow Control: Regulating the flow of data to prevent a fast sender from overwhelming a slow receiver.
• Medium Access Control: Managing access to a shared communication channel to prevent collisions in multi-access networks.
• Reliability: Providing mechanisms to ensure frames are delivered in the correct order and without loss.

Bridges are used to connect two or more network segments at the data link layer. Their primary uses include:

• Network Segmentation: Dividing a large, congested network into smaller, manageable segments to reduce traffic.
• Performance Improvement: Filtering traffic so that local traffic remains within its segment, thereby increasing overall network bandwidth.
• Protocol Transparency: Connecting different network segments that may use different physical media but the same data link layer protocol.
• Extending Network Distance: Acting as a repeater to extend the physical range of a local area network.