AN1630 High Performance Communication Networks M.E Question Bank : niceindia.com
Name of the College : Noorul Islam College of Engineering
University : Anna University
Degree : M.E Communication Systems
Department : Electronics and Communication Engineering
Subject Code/Name : AN 1630 – High Performance Communication Networks
Year : 2nd
Semester : 3rd
Document Type : Question Bank
Website : niceindia.com
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/niceindia.com/3116-AN1630-_High_Performance_Communication_Networks.pdf
High Performance Communication Networks Question Paper
Unit : 1 Packet Switched Networks:
Part : A:
1.What is the function of physical layer? :
Physical layer transmits bits by converting them into electrical or optical signals. Physical layer uses synchronization bits to synchronize the receiver.
Related : Noorul Islam College of Engineering XCS353 Computer Networks M.Sc Question Bank : www.pdfquestion.in/3143.html
2.What is preamble? :
To assist the synchronization in the physical layer the transmitter inserts a specific bit pattern called preamble, at the beginning of the packet.
3.What is the function of data link layer? :
Data link layer supervises the transmission of packets by the physical layer. It adds a sequence number and error detection bits (CRC).
4.What is encapsulation and decapsulation? :
The appending of control fields to a packet is called encapsulation. The reverse process stripping the control fields is called decapsulation.
5.What are the two layers of data link layer? :
Media access control and logic link control are the two layers of data link layer.
6.What is the function of network layer? :
Routing is the main function of network layer. The network layer appends unique networks addresses of source and destination.
7. What is the function of session layer? :
Session layer supervices the dialogue between two computers. It can setup a connection prior to an exchange of information between the machines.
8.What is re-sequencing? :
Re-sequencing may be necessary because packets may not be received in the order in which they are transmitted.
9.Why packetization is needed? :
Packetization may be necessary because the size of message may be larger than the size of packets accepted by the network layer.
10. Define syntax? :
A set of rules for representing the information is reffered to as syntax. Different computer uses different syntaxes.
11. What is the use of application layer? :
Application layer provides frequently needed communication services such as file transfer , terminal emulation , remote login ,directory service and remote job execution.
12.What do you meant by self synchronizing? :
Receiver uses the transitions to synchronize to the received signal , such a code is said to be self synchronizing.
13. What is called the efficiency of the MAC? :
The fraction of useful time when many nodes want to transmit is called efficiency of the MAC. The fraction of time that the nodes use the transmission channel to transmit the packets successfully is approximately equal to 1/(1+5a). Where a is the ratio of propagation time (PROP) to a packet transmission time (TRANS).
14. What is spanning tree? :
A spanning tree in a graph is a sub graph that is a tree and that spans all the nodes.
15.What is VLAN? :
A VLAN is a subset of computers and ports with a single switched LAN domain. The subset is defined according to administrative rules.
16.what is a token? :
Token is a 3 byte frame that consists of start of frame and access control and an ending delimiter each of one byte long.
17.What do you meant by release after transmission and release after reception? :
A node releases the token right after it finishes transmitting its packets is called release after transmission and a node that transmits waits until it has completely received its last packet before releasing the token is called release after reception.
18. What are the three parameters defined by service quality levels of SMDS? :
The three parameters are address screening , limit on number of simultaneous packets and information rate.
19. What is called frame relay? :
Frame relay is a connection oriented data transport service for public switched networks. The frame relay protocols are modification of X.25 standards.
20. What are the advantages of DQDB MAC protocol? :
It is very efficient
There is no loss of capacity due to collision
The head station continuously generates an idle frame