CS601 Current Solved Papers Fall 2021 by Adil Alvi

CS601 CURRENT PAPERS FALL 2021

Q1. What is CSMA/CA?

To minimize the chance of collision and, therefore, increase the performance, CSMA was developed. CSMA/CA was invented for Wireless Networks

2) Primary station and secondary station/Polling:

Polling works with topologies in which one device is designated as a primary station and the other devices are secondary stations. All data exchanges must be made through primary device even when the ultimate destination is a secondary device

Q3. In which layer switch and hub are works?

A link-layer switch (or switch) operates in both the physical and the data-link layers Hub is a device that operates only in the physical layer

Q4. How many types of HDLC frames?

HDLC defines three types of frames: 1) information frames (I-frames), 2) Supervisory frames (Sframes), 3) Unnumbered frames (U-frames)

Q5. Write specification of IEEE 802.11 PROJECT?

IEEE has defined the specifications for a wireless LAN, called IEEE 802.11, which covers the physical and data-link layers. It is sometimes called Wireless Ethernet

Q6. Write the difference between error correction and error detection?

In error detection, we are only looking to see if any error has occurred (Yes or No). We are not interested in the number of corrupted bits in Detection. Single-bit error is same as a Burst error. In Error Correction, we need to know the exact number of bits that are corrupted and, their location in the message

Q7. How many Types of frames?

Management Frames, Control Frames, Data Frames

Q8. How many types of telephone network?

There are three main types of telephone connections, each supported by different technologies. These are: Analogue telephone connections. Integrated Services Digital Network (ISDN) telephone connections.

Q9. Write three controlled-access methods?

Three controlled-access methods: 1) Reservation, 2) Polling, 3) Token Passing

Q10. In which layer of OSI model hub and switches falls?

In Layer1 of OSI model hub and switch fall

Q11. Write Carriers of LATA?

Carrier that handles Intra-LATA are called a Local Exchange Carrier (LEC) and the ones that handle Inter-LATA are called Interexchange Carriers (IXCs)

Q12. What is Attenuation? Write name of Attenuation characteristics and its Unit?

Attenuation means a loss of energy. When a signal, simple or composite, travels through a medium, it loses some of its energy in overcoming the resistance of the medium. Unit of Attenuation is Decibel or dB and this is Characteristics of a Wireless LAN

Q13. SONET correspond to physical and data link layer. Write three specific layers correspond to data link layer?

SONET Layers: SONET defines 4 layers, namely photonic layer, Section layer, Line layer and Path layer. The photonic layer is the lowest and performs the physical layer activities while all other 3 layers correspond to Data link layer of OSI model.

Q14. Identify that which belong to random-access protocol/controlled access?

ALOHA RANDOM ACCESS POLLING CONTROLLED ACCESS RESERVATION CONTROLLED ACCESS CSMA/CD RANDOM ACCESS CSMA/CA RANDOM ACCESS

Q15. ALOHA is a multiple access protocol for transmission of data via a shared network channel. Considering this given below is a table of the terms used in pure ALOHA, you are required to mention the complete names of the respective terms/legends?

Terms/Legends

Names

K Number of attempts TFR Maximum propagation time Tp Average transmission time R (Back-off time) R x Tp or R x Tfr TB (random number): 0 to 2k - 1

Q16. Following table contains the list of connecting devices in a computer network you are required to mention the names of Open System Interconnection Model (OSI) layers on which these devices do operate?

Connecting Device

OSI Layer

Hub Physical Layer Switch Data-link Layer Router Network Layer

Q17. Consider two stations i.e. primary and secondary. Primary station can send commands while secondary station only responds. Identify the transfer mode of high level data link control (HDLC) in this case?

Normal Response Mode (NRM) − Here, two types of stations are there, a primary station that send commands and secondary station that can respond to received commands. It is used for both point - to - point and multipoint communications.

Q18. What Loop Problem in a Switch?

Redundant switches create Loops in the system. Created when two or more broadcasting LANs are connected by more than one switch

Q19. Write two names of layers of IEEE project 802?

A way of specifying functions of the physical layer and the data-link layer of major LAN protocols and also split the data link layer into two different layers -- an LLC layer and a MAC layer.

Q20. Write Characteristics of a Wireless LAN?

Several characteristics of wireless LANs either do not apply to wired LANs or the existence of these is negligible and can be ignored 1) Attenuation, 2) Interference, 3) Multipath Propagation,

4. Error

Q21. Mention the maximum speed of following Ethernet technologies?

1. Standard Ethernet, 2) Fast Ethernet

A standard Ethernet network can transmit data at a rate up to 10 Megabits per second (10 Mbps). A Fast Ethernet network can transmit data at a rate up to 100 Megabits per second (100 Mbps).

Q22. Write types and subtypes of Multiple Access Protocol?

Q23. Cable network uses two distinguished components i.e. CM and CMTS. You are required to mention the complete names for CM and CMTS. Also mention the places where these devices are used?

1) Cable Modem (CM):

Cable modem, modem used to convert analog data signals to digital form and vise versa, for transmission or receipt over cable television lines, especially for connecting to the Internet.