Saturday, 23 July 2016

100 Interview Question Answers For Computer Networking-Part4

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61. What is Beaconing?
The process that allows a network to self-repair networks problems. The stations on the
network notify the other stations on the ring when they are not receiving the transmissions.
Beaconing is used in Token ring and FDDI networks.
62. What is terminal emulation, in which layer it comes?
Telnet is also called as terminal emulation. It belongs to application layer.
63. What is frame relay, in which layer it comes?
Frame relay is a packet switching technology. It will operate in the data link layer.
64. What do you meant by "triple X" in Networks?
The function of PAD (Packet Assembler Dissembler) is described in a document known as X.3.
The standard protocol has been defined between the terminal and the PAD, called X.28;
another standard protocol exists between hte PAD and the network, called X.29. Together,
these three recommendations are often called "triple X"
65. What is SAP?
Series of interface points that allow other computers to communicate with the other layers of
network protocol stack.
A generic term for section of a large networks usually separated by a bridge or router.
67. What is Router?
Hybrid devices that combine the features of both bridges and routers.
68. How Gateway is different from Routers?A gateway operates at the upper levels of the OSI model and translates information between
two completely different network architectures or data formats.
69. What are the different type of networking / internetworking devices?Repeater:
Also called a regenerator, it is an electronic device that operates only at physical layer. It
receives the signal in the
network before it becomes weak, regenerates the original bit pattern and puts the refreshed
copy back in to the link.
These operate both in the physical and data link layers of LANs of same type. They divide a
larger network in to smaller
segments. They contain logic that allow them to keep the traffic for each segment separate and
thus are repeaters that relay a frame only the side of the segment containing the intended
recipent and control congestion.
They relay packets among multiple interconnected networks (i.e. LANs of different type). They
operate in the physical,
data link and network layers. They contain software that enable them to determine which of
the several possible paths is the best for a particular transmission.
They relay packets among networks that have different protocols (e.g. between a LAN and a
WAN). They accept a
packet formatted for one protocol and convert it to a packet formatted for another protocol
before forwarding it. They operate in all seven layers of the OSI model.
70. What is mesh network?A network in which there are multiple network links between computers to provide multiple
paths for data to travel.
71. What is passive topology?
When the computers on the network simply listen and receive the signal, they are referred to
as passive because they don’t amplify the signal in any way. Example for passive topology -
linear bus.
72. What are the important topologies for networks?

BUS topology:
In this each computer is directly connected to primary network cable in a single line.
Inexpensive, easy to install, simple to understand, easy to extend.
STAR topology:
In this all computers are connected using a central hub.
Can be inexpensive, easy to install and reconfigure and easy to trouble shoot physical
RING topology:
In this all computers are connected in loop.
All computers have equal access to network media, installation can be simple, and signal does
not degrade as much as
in other topologies because each computer regenerates it.
73. What are major types of networks and explain?
Server-based network
Peer-to-peer network
Peer-to-peer network, computers can act as both servers sharing resources and as clients using
the resources.
Server-based networks provide centralized control of network resources and rely on server
computers to provide
security and network administration
74. What is Protocol Data Unit?
The data unit in the LLC level is called the protocol data unit (PDU). The PDU contains of four
fields a destination
service access point (DSAP), a source service access point (SSAP), a control field and an
information field. DSAP, SSAP are addresses used by the LLC to identify the protocol stacks on
the receiving and sending machines that are generating and using the data. The control field
specifies whether the PDU frame is a information frame (I -
frame) or a supervisory frame (S - frame) or a unnumbered frame (U - frame).
75. What is difference between baseband and broadband transmission?In a baseband transmission, the entire bandwidth of the cable is consumed by a single signal. In
broadband transmission, signals are sent on multiple frequencies, allowing multiple signals to
be sent simultaneously.
76. What are the possible ways of data exchange?(i) Simplex (ii) Half-duplex (iii) Full-duplex.
77. What are the types of Transmission media?Signals are usually transmitted over some transmission media that are broadly classified in to
two categories.
Guided Media:
These are those that provide a conduit from one device to another that include twisted-pair,
coaxial cable and fiber-optic
cable. A signal traveling along any of these media is directed and is contained by the physical
limits of the medium. Twisted-pair and coaxial cable use metallic that accept and transport
signals in the form of electrical current. Optical fiber is a glass or plastic cable that accepts and
transports signals in the form of light.
Unguided Media:
This is the wireless media that transport electromagnetic waves without using a physical
conductor. Signals are
broadcast either through air. This is done through radio
communication, satellite communication and cellular telephony.
78. Difference between the communication and transmission?
Transmission is a physical movement of information and concern issues like bit polarity,
synchronization, clock etc.
Communication means the meaning full exchange of information between two communication
79.The Internet Control Message Protocol occurs at what layer of the seven layer model?

80.Which protocol resolves an IP address to a MAC address?


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