Testové otázky

18. IP protocol provides:

1. Network technology independent addressing

2. Packet fragmentation

3. Undeliverable packet removals ttl

4. Message segmentation and assembling

19. TCP protocol provides:

1. Reliable service

2. Connectionless service

3. Data flow control

4. Connection oriented service

5. Unreliable service

20. What is the reason of usage RTS/CTS handshake in WLANs?

1. To increase the coverage area

2. To solve hidden node problem

3. To decrease the latency

4. To implement QoS support

21. Each end-node communicating node in TCP/IP environment has to know:

1. Own IP address

2. Its subnetwork mask

3. Physical address of default router

4. IP address of default router

5. The name of DNS server

22. Find maximum number of unicast IP addresses of a network, where one of its host is specified by its IP address and the length of subnetwork mask – 133.2.85.97/22

1. 510

2. 1022

3. 254

4. 253

22, 32 - 22 = 10, 2^10 = 1024-2

23. The multiple access method used in WiFi networks is called:

1. Cambridge ring

2. CSMA/CD

3. CSMA/CA

4. Distributed coordination function

24. Find maximum number of subnetworks that can be created in addressing space 133.2.00/16 with constant length of subnetwork mask 22:

1. 32

2. 64

3. 128

4. 16

16, 2^16 = 64 XXX, 22 2^10 = 1024

25. Does the host with IP address 199.25.48.202 belong to the network specified by address 199.25.48.198/28

1. No

2. Yes

3. Yes, but the address is the broadcast address

4. It is not possible to decide because of lack of information

26. Do following hosts with IP addresses 111.37.59.238/26 and 111.37.59.193/26 belong to the same network?

1. No

2. Yes

3. It depends whether both hosts are computers or one is computer and the other is an IP phone

4. It is not possible to decide because of lack of information

27. OFDMA technology is based on:
- time slot allocation,
- channel division in mutually orthogonal subchannels,
- frequency channel allocation,
- allocation of a set of frequency subchannels to each terminal/service,

28. Before the communication between terminals in circuit-switched networks can start it is necessary:
- to establish the virtual circuit on the transport level,
- to establish virtual circuit on the session layer,
- to establish the physical circuit,
- to send the test packet to learn whether the destination is reachable,

29. 100BaseTX Ethernet technology requires following medium:
- UTP at least of 3rd and 4th category,
- coaxial cable RG-58 with impedance 50 (,
- UTP at least of 7th category,
- UTP at least of 5th category,

30. Multiplexing methods are used for:
- call admission procedure,
- reduction of station data streams,
- communication channel sharing among individual data flows controlled by single device,
- error protection of data when media is being accessed,

31. Which media type/types is/are specified for 1000BaseX Ethernet?
- free space optical link,
- both multimode and single mode optical fibres or special metallic cables,
- multimode optical fibres only,
- only optical fibres at the band 1310 nm,

32. The goal/-s of session layer is/are:
- conversion of connectionless service to connection oriented,
- session control between application entities,
- message assembling,
- error correction,

33. To enable proper packet routing in the Internet the packet header has to contain:
- destination and source network addresses,
- virtual circuit identifier,
- physical address of the next router,
- type of data,
- user identifier and cipher key,

34. Is the circuit-switched network suitable for all real-time services?
- no, especially when the traffic is high,
- yes, always,
- yes, when the connection does not lead via satellites and when sufficient channel capacity is available,
- no, as the circuit may be “stolen” by higher priority service at any time of service duration,