Computer Knowledge

Computer Networks

2,614 Questions

Computer networks involve the architecture, protocols, and security measures used for digital communication. This collection covers OSI model layers, IP addressing, data transmission, and cryptographic standards. These concepts are vital for the computer knowledge sections of banking and government exams.

OSI model layersNetwork protocolsIP subnet maskingData encryption standardsServer configurationsNetwork commands

Computer Networks Questions

Multiple choice technology security

In the OSI reference model, on which layer can a telephone number be described?

  1. Layer1, as a telephone number represents a series of electrical impulses

  2. Layer 3, because a telephone number describes communication between different networks

  3. This depends on the nature of the telephony system (for instance, Voice-over-IP versus public switched telephony network (PSTN))

  4. None, as the telephone system is a circuit-based network and the OSI system only describes packet-switched networks
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Telephone numbers operate at different layers depending on the technology: in PSTN they represent circuit identifiers at layer 1-2, while in VoIP they function as application-layer addressing at layer 5-7. The OSI model was designed for packet-switched networks, so traditional circuit-switched telephony doesn't map cleanly.

Multiple choice

Which is the preferred protocol to call a web service?

  1. HTTP

  2. SMTP

  3. FTP

  4. SOAP

  5. WSDL
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

SOAP is an XML-based messaging framework specifically designed for exchanging formatted data across the internet. For example, using request and reply messages or sending entire documents. It is the best method for accessing a web service.

Multiple choice

Which of the following functionalities must be implemented by a transport protocol over and above the network protocol?

  1. Recovery from packet losses

  2. Detection of duplicate packets

  3. Packet delivery in the correct order

  4. End to end connectivity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Transport protocols are mainly for providing end to end connections by making sockets. Recovery from packet loss & delivery in correct order, duplication is checked by Data link layer.

Multiple choice

Which of the following functionalities must be implemented by a transport protocol over and above the network protocol?

  1. Recovery from packet losses

  2. Detection of duplicate packets

  3. Packet delivery in the correct order

  4. End to end connectivity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Transport protocols are mainly for providing end to end connections by making sockets. Recovery from packet loss & delivery in correct order, duplication is checked by Data link layer.

Multiple choice

Which of the following assertions is FALSE about the Internet Protocol (IP)?

  1. It is possible for a computer to have multiple IP addresses

  2. IP packets from the same source to the same destination can take different routes in the network

  3. IP ensures that a packet is discarded if it is unable to reach its destination within a given number of hops

  4. The packet source cannot set the route of an outgoing packets; the route is determined only by the routing tables in the routers on the way
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Internet protocol ensures that a packet is forwarded if it is unable to reach its destination within a given no. of hops. One computer can have multiple IP addresses also packets having same source & destination can take different routes. Source doesn't decide where to route the packet, but it is decided by the routing tables at intermediate routers.

Multiple choice

Host A is sending data to host B over a full duplex link. A and B are using the sliding window protocol for flow control. The send and receive window sizes are 5 packets each. Data packets (sent only from A to B) are all 1000 bytes long and the transmission time for such a packet is 50 micro second. Acknowledgement packets (sent only from B to A) are very small and require negligible transmission time. The propagation delay over the link is 200 micro second. What is the maximum achievable throughput in this communication?

  1. 7.69 × 106 bps

  2. 11.11 × 106 bps

  3. 12.33 × 106 bps

  4. 15.00 x 106 bps
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Data packet size = 1000 byte        Number of packets = 5        Total data = 5000        Transmission time = 50 micro second/packet        Propagation delay = 200 micro second        So for 5 packets = 50 * 5 = 250 micro second        Total time for 5 packets = 250 + 200 = 450 micro second        Rate = Data/time = 5000*1000000/450 = 11.11*1000000 bps