DTA

Question 1

Which of the following are LAN technologies?
1) Frame Relay
2) SDH
3) Ethernet
4) MPLS
5) WLAN

Answer 1

3)

Question 2

Which logical topology does Ethernet (802.3) have?
1) Star topology
2) Bus topology
3) Ring topology

Answer 2

2)

Question 3

Which network protocol will be used for voice and data communication in the near future?
1) FDDI
2) TCP/IP
3) VHF
4) X.25

Answer 3

2)

Question 4

Name the requirements which are important for network planning.
1) Time Delay
2) Acceptable Jitter
3) Power consumption
4) Thermal power loss
5) Packetloss rate
6) Processor speed
7) Bandwith
8) Rack colour
9) Age of the network designer
10) Network security

Answer 4

1)
2)
5)
7)
10)

Question 5

Which of the following protocols work “connection-less”?
1) TCP
2) IP
3) UDP
4) Frame Relay

Answer 5

2)
3)

Question 6

Which of the following protocols work “connection oriented”?
1) TCP
2) IP
3) UDP
4) Frame Relay
5) MPLS (partly)

Answer 6

1)
4)
5)

Question 7

Which of the procedures for transferring data packets from one interface to another of a network device is a “global” process?
1) Forwarding
2) Routing

Answer 7

2)

Question 8

Which of the following protocols are routing protocols?
1) MPLS
2) OSPF
3) IS-IS
4) BPDU
5) TCP/IP
6) BGP

Answer 8

2)
3)
6)

Question 9

Which of the following devices seperate networks?
1) Repeaters
2) Firewalls
3) Non-configurable switches
4) Modems
5) Routing devices

Answer 9

2)
5)

Question 10

Up to which OSI-Layer does a classical switch operate?
1) Layer 3
2) Layer 2
3) Layer 4

Answer 10

2)

Question 11

Name the 5 network characteristics checked by a firewall.
1) Source port
2) Destination IP-adress
3) Destination port
4) Hostname
5) Source MAC-adress
6) Destination MAC-adress
7) Source IP-adress
8) Layer-4 protocol
9) Ethernet type
10) MTU size

Answer 11

1)
2)
3)
7)
8)

Question 12

What is the maximum size of a standard Ethernet-frame (802.3) without additional VLAN information? Synchronisation and start-frame delimiter are neglected.
1) 1500 bytes
2) 1518 bytes
3) 1460 bytes

Answer 12

2)

Question 13

When transmitting data via optical fibres there are several „optical windows” in use. Which wave length does the most frequently used second optical window have?
1) 650 nm
2) 850 nm
3) 1310 nm
4) 1550 nm

Answer 13

3)

Question 14

SFP modules are deployed in switches, multiplexers and servers. For which speed are „SFP+” modules designed?
1) 100 Mbit/s
2) 1 Gbit/s
3) 10 Gbit/s
4) 40 Gbit/s

Answer 14

3)

Question 15

What does the abbreviation “SSID” stand for in a W-LAN environment?
1) Station Secure Identifier
2) Student Social Identifier
3) Service Set Identifier
4) Sub System Identifier

Answer 15

3)

Question 16

Which network access method is used in W-LANs?
1) CSMA/CA
2) CSMA/CD
3) CSMD/AC

Answer 16

1)

Question 17

Which of these are network protocol analysis tools?
1) Tcpdump
2) Sniffer (e.g. Wireshark)
3) OTDR
4) Cable tester

Answer 17

1)
2)

Question 18

Which are the main points to perform troubleshooting within a network?
1) Only the network management personal is responsible for the error analysis
2) Up-to-date and complete documentation
3) Errors occur only due to problems inside the Service Providers network
4) Collaboration between networking people and end system administrators are necessary to detect complex errors

Answer 18

2)
4)

Question 19

In which data communication area are LC-plugs deployed?
1) 1000 BaseT
2) Fibre optics
3) 100 BaseT
4) UTP cable

Answer 19

2)

Question 20

Different redundancy concepts exist within a network environment. Which are the most important points to consider?
1) The Connection of important end-systems to different network components (e.g. switches)
2) The division of redundant components into different power circuits
3) It is necessary to restart network components every day, so that the standby systems can be checked.
4) The Loadsharing via redundant components (as far as possible). A single component, however, has to deal with the complete network load.
5) The monitoring of only a few of the network components involved is sufficient, so that (……)
6) It is enough to only monitor the active network components. The standby systems don’t need to be monitored

Answer 20

1)
2)
4)

Question 21

What has to be considered when replacing network components?
1) The configuration of the spare component has to be checked and has to be adapted (if necessary) before the replacement.
2) Spare parts can be used for replacement without knowing which configuration/software is installed on the device.
3) Before the replacement of network components you have to pay attention to the proper labelling of all network cables.
4) It is unnecessary to check the management connection after the component replacement.

Answer 21

1)
3)

Question 22

Which requirements have to be called for, when using external network service providers?
1) Availability values of the service
2) Maximum bit-error rate on lines
3) Colour of patch cables
4) Mean time to repair (MTTR) and time to restore the service
5) Unfriendlieness of the service hotline
6) How unprotected the network of the external service provider is

Answer 22

1)
2)
4)

Question 23

What is the maximum number of IPv4-hosts that can be addressed in a class C network?
1) 1024
2) 252
3) 254
4) 255

Answer 23

3)

Question 24

In which OSI layer does the transition between LAN standard and WAN standard take place?
1) Layer 5
2) Layer 4
3) Layer 3
4) Layer 2

Answer 24

3)

Question 25

Which of the following protocols are on the "application layer"? 1) HDLC 2) HTTP 3) SMTP 4) TCP 5) SDH 6) Ethernet 7) TELNET

Answer 25

2) 3) 7)

Question 26

In which way are unicast MAC addresses created? 1) 2 byte OUI, 2 byte sequential numbering 2) 3 byte OUI, 4 byte sequential numbering 3) 3 byte OUI, 3 byte sequential numbering 4) 48 bit sequential numbering

Answer 26

3)

Question 27

Which standardization organisation is responsible for the assignment of official IP-Adressen, TCP/UDP-ports etc.? 1) IANA as part of ICANN 2) ISO 3) TIA 4) IETF

Answer 27

1)

Question 28

Which address within a LAN (Ethernet) is necessary to reach a communication partner via the media? 1) IP-adress 2) SSID 3) E.164 address 4) UDP port number 5) MAC address

Answer 28

5)

Question 29

How many IPv4 address classes exist? 1) 3 classes 2) 4 classes 3) 5 classes 4) 6 classes

Answer 29

3)

Question 30

How many IPv4 unicast address classes are available for internet usage? 1) 3 classes 2) 4 classes 3) 5 classes 4) 6 classes

Answer 30

1)

Question 31

Which of the following addresses is the broadcast-address for IPv4 class C network 192.9.217.0/24 ? 1) 192.9.217.64 2) 191.9.217.255 3) 192.9.217.255 4) 192.9.217.254

Answer 31

3)

Question 32

Which is / are the IP-address for Loopback within an IP-station? 1) 168.0.0.1 2) 127.0.0.1 3) ::1 4) 255.255.255.0 5) Fe80::1

Answer 32

2) 3)

Question 33

Which address within the IPv6 environment replaces the IPv4 Broadcast address? 1) Link local adress 2) Global unicast address 3) Loopback address 4) Anycast address 5) All nodes multicast address

Answer 33

5)

Question 34

With which protocol in an IPv4 environment a MAC address to an IPv4 station is determined? 1) RIP 2) ICMP protocol 3) TFTP protocol 4) ARP protocol

Answer 34

4)

Question 35

What is meant by the acronym PAT? 1) Replacement (exchange) of the IPv4 destination address 2) Replacement (exchange) of the UDP/TCP source port 3) Replacement (exchange) of the IPv4 source address 4) Replacement (exchange) of the UDP/TCP destination port

Answer 35

2) 4)

Question 36

During connection establishment from different internal clients to the internet, a router only uses one official ip address in direction to the internet. Which kind of NAT is used here (This is also called NAPT)? 1) PAT 2) Destination NAT 3) Source NAT (dynamic) 4) Source NAT (static)

Answer 36

1) 3)

Question 37

To which class of routing protocols does the OSPF belong? 1) Link state protocols 2) Distance vector protocols 3) Advanced distance vector protocols

Answer 37

1)

Question 38

There are the following routing entries in a router: 10.20.0.0/16 via way A 10.20.3.0/24 via way B 10.20.3.128/27 via way C A data packet is to be sent to the address: 10.20.3.54. Which way does the data packet use?

Answer 38

Way B

Question 39

Name an example for an "Exterior Gateway Protocol" (EGP) 1) IS-IS 2) OSPF 3) BGP

Answer 39

3)

Question 40

Which criteria are used on an IP router to determine the next hop? 1) The destination MAC-address 2) The destination X.25-address 3) The destination IP-address 4) The destination UDP/TCP port number 5) The metric

Answer 40

3) 5)

Question 41

Which mechanism is used to transport IP packets which exceed the maximum transfer unit size of the used media? 1) Packets bigger than the MTU size will be discarded 2) There will be a fragmentation up to the maximum size (64 KByte), if the DF-bit is set 3) There will be a fragmentation up to the maximum size (64 KByte), if the DF-bit is not set

Answer 41

3)

Question 42

How does the "three-way handshake" within the TCP work during the connection establishment? TCP connection with the following sequence: 1) ->SYN; <-SYN; ->ACK; <-ACK 2) ->SYN; <-SYN,ACK; ->ACK 3) ->SYN; <-RST; ->ACK

Answer 42

2)

Question 43

How can the receiver of a TCP connection with a full receive buffer prevent the sender from sending further packets? 1) The receiver resets the connection with a RST packet 2) The receiver doesn't send any more ACK updates 3) The receiver reduces the receive window size down to 0

Answer 43

3)

Question 44

SMTP is the abbreviation for 1) Student Mail Terminal Protocol 2) Session Management Transport Protocol 3) Simple Mail Transport Protocol

Answer 44

3)

Question 45

Which are the 2 most important fields of the SMTP mail envelope? 1) From: example@abc.com 2) MAIL FROM: 3) To: receiver@abc.com 4) RCPT TO:

Answer 45

2) 4)

Question 46

Which of the following is not a command of the HTTP protocol? 1) GET 2) HEAD 3) SYNC 4) POST 5) NOSE

Answer 46

3) 5)

Question 47

IANA has registered FMTP on which TCP/UDP port? 1) 22 2) 8600 3) 22000 4) 8500 5) 1024

Answer 47

4)

Question 48

Name the OSI-layers on which the FMTP protocol is defined. 1) Layer 4 2) Layer 5 3) Layer 7 4) Session Layer 5) Application Layer

Answer 48

2) 4)

Question 49

DFS is connected via network to which of the following national partners? 1) German weather service (DWD) 2) Airlines (Lufthansa, LH systems) 3) DFS Aviation Services (DAS) 4) Sailing clubs 5) Network of the stock exchanges 6) Highway Patrol

Answer 49

1) 2) 3)

Question 50

Which network forms the platform for air navigation service providers across Europe to reliably exchange data? 1) Internet as an inexpensive IP network to exchange surveillance data between ANSPs 2) PENS as an IP network for various services (surveillance, FMTP, AMHS, NM, EAD,…) 3) IP networks in each FAB area

Answer 50

2)

Question 51

Name two of the ATS global networks defined by ICAO.

Answer 51

AFTN (aeronautical fixed telecommunication network), ATN (aeronautical telecommunication network)

Question 52

Which applications were defined for the ATN network by ICAO? 1) Context management 2) RNAV 3) Controller pilot data link communications 4) WIFI 5) Automatic dependent surveillance contract 6) Airport-CDM services 7) Data link flight information service 8) Centralized services 9) Air traffic services message handling service 10) Online data interchange (OLDI)

Answer 52

1) 3) 5) 7) 9)

Question 53

An aircraft addresses an ATN end system on the ground at an ANSP. What type of address is currently in use for this ? 1) A worldwide unique IPv4 address 2) A worldwide unique IPv6 address 3) A worldwide unique NSAP addres

Answer 53

3)

Question 54

What routing protocol is used in the ATN between various routing domains ? 1) Border gateway protocol (BGP) 2) Open shortest path first (OSPF) 3) Inter-domain routing protocol (IDRP)

Answer 54

3)

Question 55

I am a member of the AFTN network and submit a message that is addressed to the control tower in Sydney. As the originator of that message, do I receive a receipt that the message was successfully delivered ? 1) Yes, a delivery receipt is automatically sent by the end device in Sydney control tower. 2) No, I will not receive a delivery receipt. Messages are not saved temporarily. If there are any transmission errors on the path, the message will unfortunately be lost. 3) No, I will not receive a delivery receipt. Messages are, however, transferred using the store-and-forward principle. This guarantees that messages will automatically be resent if there is a disruption in the transmission line.

Answer 55

3)

Question 56

Messages within the AFTN network are given various levels of priority for transmission. Which of the priority codes is the highest ? 1) DD 2) GG 3) SS 4) FF 5) KK

Answer 56

3)

Question 57

Which designation is used for the user interface as the access point to the AMHS network ? Messages are submitted to the AMHS network via this interface: 1) Message Transfer Agent (MTA) 2) Message Store (MS) 3) Access Unit (AU) 4) User Agent (UA)

Answer 57

4)

Question 58

State the TCP/IP Model and name examples for each layer.

Answer 58

* Application (OSI 5-7) (HTTP/FTP/SMTP/SSH/DNS) * Transport (OSI 4) (TCP/UDP) * Internet (OSI 3) (IP/ICMP) * Link (OSI 1-2) (ADSL/Ethernet/SDH-PDH/802.11)

Question 59

Name different classes of services for voice, video, background traffic.

Answer 59

Platinum: voice Gold: video Silver: best effort Bronze: background traffic

Question 60

Differentiate between link state and distance vector protocols.

Answer 60

Link state: Status of the entire topology Distance vector: Status of local topology

Question 61

Name examples for an "Interior Gateway Protocol" (IGP) 1) IS-IS 2) OSPF 3) BGP 4) RIP

Answer 61

1) IS-IS 2) OSPF 4) RIP

Question 62

Describe the term route summarisation.

Answer 62

In larger networks, you don't want to enter every small networks individually in a routing table. So forwarding routing information is summarised as far as possible with a common prefix. Example: − 192.168.0.0/24 − 192.168.1.0/24 − 192.168.2.0/24 − 192.168.3.0/24 can simply be summarised as: 192.168.0.0/22

Question 63

Eurocontrol has registered ASTERIX on which TCP/UDP port? 1) 22 2) 8600 3) 22000 4) 8500 5) 1024

Answer 63

2) 8600

Question 64

What is RTT?

Answer 64

The time limit for the acknowledgement of a segment can be defined via the Round Trip Time. (für Timeoutberechnung)

Question 65

What is the meaning of MSS?

Answer 65

Maximum Segment Size ensures that a TCP packet including IP header and TCP header (typically 40 bytes) fit into a link layer frame and does not have to be fragmented. MSS is exchanged directly after initialising a TCP connection (in SYN packets).

Question 66

What is determined by the sliding window size?

Answer 66

The sliding window mechanism facilitates the transmission of a number of segments or a defined data volume without waiting for the acknowledgement for each segment

Question 67

What errors cannot be found by a software network analyser?

Answer 67

physical errors like CRC Errors

Question 68

What errors can be found by a software network analyser?

Answer 68

* Time behavior * IP connection termination

Question 69

What's the different approach of FTP passive mode to active mode?

Answer 69

In passive mode, the control connection and the data connection from the FTP client in the direction of the server are established. This removes any problems with NAT.

Question 70

Which UDP port uses NTP?

Answer 70

port 123