CS2060-HIGH SPEED NETWORKS
Question bank
Department:ECE
Unit -1
Part-A
1. Differentiate Frame relay and X.25 packet-switching service
-> Call control signaling is carried on a separate logical connection from user data. Thus, intermediate nodes need not maintain state tables or process messages relating to call control on an individual per-connection basis
-> Multiplexing and switching of logical connections takes place at layer2 instead of layer3, eliminating one entire layer of processing
->There is no hop-by-hop flow control and error control. End-to-end flow control and error control are the responsibility of a higher layer, if they are employed at all
2. What is jitter
The packets between a given source and destination may vary in length, may take different routes, may be subject to varying delays in the switches they encounter, the overall packet delay can vary substantially. This phenomenon, called JITTER may not be desirable for some application; for example in realtime applications including telephone voice and real-time video
3. List out some of the control functions of LAPF core
Frame delimiting, alignment and transparency
Frame multiplexing/demultiplexing using the address field
Detection of transmission errors
Congestion control functions
4. What is called a cell in ATM
In ATM, the information flow on each logical connection is organized into fixed size packets called cells
5. What are the planes in protocol reference model
User plane
Control plane
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Management plane
6. What are the advantages of virtual paths
Simplified network architecture
Increased network performance and reliability
Reduced processing and short connection setup time
Enhanced network services
7.
What is VPI
The Virtual path identifier constitutes a routing field for the network. It is 8 bits at the user-network interface and 12 bits at the network-network interface.