CS610 Final Term 2008 Paper of Computer Network
Fall 2010
Time: 120 min
M = Marks = 70
Question No: 1 ( M - 1 ) http://vuzs.net
The number of connections needed for N computer in direct point to point communication is equal to:
► (N2 –N)/2
► N(N- 1)
► N2
► None of the given
Question No: 2 ( M - 1 ) http://vuzs.net
When an application--------------- data, it makes a copy of the data available to all other computers on the network.
► Multicasting
► Unicasting
► None of the given
Question No: 3 ( M - 1 ) http://vuzs.net
Ethernet uses a ------ bit static addressing scheme in which each device is assigned a unique address by the manufacturer.
► 64
► 48
► 32
► 8
Question No: 4 ( M - 1 ) http://vuzs.net
A system with redundant bridges might have a problem with_______ in the system.
► Loop
► Filters
► Spanning Trees
► All given choices
Question No: 5 ( M - 1 ) http://vuzs.net
The product of delay and throughput measures the _____ of data that can be present on the network.
► Area
► Volume
► Length
► None of the given
Question No: 6 ( M - 1 ) http://vuzs.net
Connectionless
service, Message-Oriented protocol, best effort delivery service,
arbitrary interaction and operating system independent are the
characteristics of _____________
► TCP
► UDP
► IP
► None of the given
Question No: 7 ( M - 1 ) http://vuzs.net
Connection-oriented
service, Point-to-point, Complete reliability, Full-duplex
communication, Stream interface, Reliable connection startup and
Graceful connection shutdown are the services provided by__________
► None of the given
► TCP
► UDP
► IP
SERVICE PROVIDED BY TCP:
Following are the services provided by TCP:
• Connection-oriented service
• Point-to-point
• Complete reliability
• Full-duplex communication
• Stream interface
• Reliable connection startup
• Graceful connection shutdow
Question No: 8 ( M - 1 ) http://vuzs.net
The process of using a routing table to select a next hop for a given datagram is called_________
► Encapsulation
► Reassembling
► Routing or forwarding
► None of the given
The process of using a routing table to select a next hop for a given datagram is called routing or forwarding.
Question No: 9 ( M - 1 ) http://vuzs.net
____________ uses distance vector approach to define routing
► BGP
► OSPF
► RIP
► None of the given
DISTANCE-VECTOR ROUTING:
• It is very simple to implement.
• Packet switch updates its own routing table first.
• It is used in RIP
Question No: 10 ( M - 1 ) http://vuzs.net
A multicast routing scheme in which the protocol software builds a delivery tree from a central point is called__________
► Distance Vector Multicast Routing Protocol (DVMRP)
► Core Based Trees (CBT)
► Protocol Independent Multicast_ Sparse Mode (PIM-SM)
► Protocol Independent Multicast _ Dense Mode (PIM-DM)
Core Based Trees (CBT): The protocol software builds a delivery tree from a central point
Question No: 11 ( M - 1 ) http://vuzs.net
One repeater _______, two repeaters ________ the maximum cable length limitation.
► doubles, cancel
► doubles, triple
► square roots, cude roots
► and, triple
www.vuzs.net
Question No: 12 ( M - 1 ) http://vuzs.net
Whenever it handles a packet, IP software needs to separate the destination address into a _________ and ___________.
► postfix, Infix
► non of these
► Infix, prefix
► prefix, suffix
Whenever it handles a packet, IP software needs to separate the destination address into a prefix and suffix
Question No: 13 ( M - 1 ) http://vuzs.net
Although message exchange can be used to bind addresses, sending a request for each binding is hopelessly inefficient.
► True
► False
Although message exchange can be used to bind addresses, sending a request for
each binding is hopelessly inefficient.
Question No: 14 ( M - 1 ) http://vuzs.net
ARP is almost always used to bind a ___-bit IP address to a ___-bit Ethernet address.
► 32, 48
► 24, 32
► 32, 64
► 32, 128
ARP is almost always used to bind a 32-bit IP addressto a 48-bit Ethernet ad
Question No: 15 ( M - 1 ) http://vuzs.net
End-to-end delivery service is connection oriented.
► True
► False
End-to-end delivery service is connection less
Question No: 16 ( M - 1 ) http://vuzs.net
A single networking technology is best for all needs.
► True
► False
here is no single networking technology that is best for all needs
Question No: 17 ( M - 1 ) http://vuzs.net
In
the 1970s large organizations began to acquire multiple networks. Each
network in the organization formed island. Employees needed to choose a
computer appropriate for each task. So they needed multiple screens,
keyboards and computers.
► False
► True
n the 1970s large organizations began to acquire multiple networks. Each network in the organization formed island. Employees needed to choose a computer appropriate for each task. So they needed multiple screens, keyboards and computers.
Question No: 18 ( M - 1 ) http://vuzs.net
Which method of Address Resolution Protocol is useful with any hardware?
Were "T" stands for Table lookup, "C" for Closed-form Computation and "D" for Data Exchange?
► T
► C
► D
► C, D
Features
Types of
Resolution
Use full with any hardware T
Address change affects all hosts T
Protocol address is determined by hardware address C
Question No: 19 ( M - 1 ) http://vuzs.net
In which method of Address Resolution Protocol the protocol address is determined by hardware address?
Were "T" stands for Table lookup, "C" for Closed-form Computation and "D" for Data Exchange?
► T
► D
► C
► T, C
Question No: 20 ( M - 1 ) http://vuzs.net
We use the term _______ to refer to a measure of the path that routing software use when choosing a route.
► routing path
► routing metric
► routing
► switching
We use the termrouting metric to refer to a measure of the path that routing software use when choosing a route
Question No: 21 ( M - 2 )
Is there a comparision between TCP/IP reference model and ISO reference model.
Question No: 22 ( M - 2 )
Does OSPF only share information within an area or does it allow communication between areas?
OSPF
allows subdivision of Autonomous System into areas. The link-status
information is propagated within an area. The routes are summarized
before being propagated to another area. It reduces overhead (less
broadcast traffic). Because it allows a manager to partition the routers
and networks in an autonomous system into multiple areas, OSPFcan scale
to handle a larger number of routers than other IGPs.
Question No: 23 ( M - 2 )
What are the implimentations of Network Address Translation?
Question No: 24 ( M - 3 )
Describe the difference between static and dynamic routing?
STATIC ROUTING:
It is one of the forms of Internet routing. In Static routing, the table is initialized
when system boots and there is no further changes.
DYNAMIC ROUTING:
In dynamic routing the table is initialized when system boots. It includes routing
software which learns routes and updates table. In this way continuous changes are
possible due to routing software.
Question No: 25 ( M - 3 )
What is the first address in the block if one of the addresses is 140.120.84.24/20?
The first address in the block is 140.120.80.0/20
WE can use the following short cut to find the first address
divide the prefix length into four groups(corresponding to the four bytes in an address) and find the number of 1s in each group
if the number of 1s in a group is 8 the corresponding byte in the first address is the same (no change)
If the number of 1s in the group is zero (no1s), the corresponding byte in the first address is 0
if the number of 1s in a group is between zero and eight, we keep the corresponding bits in that group
Question No: 26 ( M - 3 )
Write three new features of IPV6.
• IPV6 addresses are 128 bits.
• Header format is entirely different.
• Additional information is stored in optional extension headers, followed by data.
• Flow label and quality of service allows audio and video applications to establish
appropriate connections.
• New features can be added more easily. So it is extensible.
Question No: 27 ( M - 5 )
What is the difference between an interior gateway protocol and an exterior gateway protocol? Name an example of each.
INTERIOR GATEWAY PROTOCOLS (IGPs):
It is used among routers within autonomous system. The destinations lie within IGP.
EXTERIOR GATEWAY PROTOCOLS (EGPs):
It is used among autonomous systems. The destinations lie throughout Internet
Question No: 28 ( M - 5 )
As the Internet grew, the original Classful addressing scheme became a limitation, what is was the designed solution.
Question No: 29 ( M - 5 )
What are IPv6 ADDRESS NOTATION?
IPv6 ADDRESS NOTATION:
128-bit addresses unwidely in dotted decimal; requires 16 numbers:
105.220.136.100.255.255.255.255.0.0.18.128.140.10.255.255
Groups of 16-bit numbers in hex separated by colons – colon hexadecimal (or colon hex).
69DC: 8864:FFFF: FFFF: 0:1280:8C0A:FFFF
Zero-compression – series of zeroes indicated by two colons
FF0C: 0:0:0:0:0:0:B1
FF0C::B1
IPv6 address with 96 leading zeros is interpreted to hold an IPv4 address.
Question No: 30 ( M - 10 )
LIST SOME CHARACTERISTICS OF A CLIENT.
CHARACTERISTICS OF A CLIENT:
The characteristics of a client are explained below:
"Client is an arbitrary application program.
"It becomes client temporarily.
"It can also perform other computations.
"It is invoked directly by the user.
"It runs locally on the user’s computer.
"It actively initiates contact with a server.
"It contacts one server at a time.
Question No: 31 ( M - 10 )
With help of the diagram below, explain TCP Segment Format:
TCP uses single format for all messages. TCP uses the term segment to refer to a message. Each message sent from TCP on onemachine to TCP on another machine uses this format including data andacknowledgement
Field Name
|
Size (bytes)
|
Description
|
SourcePort
|
2
|
ephemeral (client) port numberSourcePort: The 16-bit port number of the process that originated the TCP segment on the source device. This will normally be an for a request sent by a client to a server
|
DestinationPort
|
2
|
DestinationPort: The 16-bit port number of the process that is the ultimate intended recipient of the message on the destination device.
|
Sequence Number
|
4
|
Sequence Number: For normal transmissions, the sequence number of the first byte of data in this segment. In a connection request (SYN) message, this carries the initial sequence number (ISN) of the source TCP.
|
Acknowledgment Number
|
4
|
Acknowledgment Number: When the ACK
bit is set, this segment is serving as an acknowledgment (in addition
to other possible duties) and this field contains the sequence number
the source is next expecting the destination to send.
|
Window
|
2
|
Window:
Indicates the number of octets of data the sender of this segment is
willing to accept from the receiver at one time. This normally
corresponds to the current size of the buffer allocated to accept data
for this connection.
|
Checksum
|
2
|
|
Urgent Pointer
|
2
|
Urgent Pointer: Used in conjunction with the URG control bit for priority data transfer. This field contains the sequence number of the last byte of urgent data.
|
Options
|
Variable
|
Options:
TCP includes a generic mechanism for including one or more sets of
optional data in TCP segment. Each of the options can be either one byte
in length or variable length. The first byte if the option kind
subfield and it’s value specifies the type of option, which in turn
indicates whether the option is just a single byte or multiple bytes.
Options that are many bytes consist of three fields
|
Note this table is also included in options column. options may vary
Subfield name
|
Size (bytes)
|
Description
|
Option-kind
|
1
|
Option-kind: specifies the option type
|
Option-length:
|
1
|
Option-length: the length of the entire option in bytes, including the option-kind and option-length fields.
|
Option-data
|
Variable
|
Option-data: the option data itself in at least one oddbll case, this field is omitted(making option length equal to 2)
|
