QUESTION BANK
1. Explain the types of File Transfer Protocol (FTP) connection?
Ans.a. FTP establishes two connections between the hosts. One connection is
used for data transfer,the other for control information(commands and
resposes).Separatation of commands and data transfer makes FTP more
efficient.The control connection uses very simple rules of communication.A
line of command or a line of respose need to be transfered at a time. The data
connection on the other hand, needs more complex rules due to variety of
data types transfered.The well-known port 21 is used for the control
connection and the well-known port 20 is used for the data connection.
2. Compare Hyper Text Transfer Protocol (HTTP) and Simple Mail Transfer
Protocol (SMTP).
Ans.b
Sr.No
SMTP
1
SMTP transfers files(i.e. e-mail
messages) from one mail server
to another mail server
2
Uses port 25 for transmission
3
SMTP messages are to be read
by humans
4
5
6
HTTP
HTTP transfers files(or objects) from
Web server to Web user agent (i.e.
Browser)
Uses port 80 for transmission
HTTP messages are to be read and
interpreted by the HTTP server and
HTTP client(i.e. Browser)
SMTP messages are stored and HTTP messages are delivered
forwarded
immediately.
SMTP is a push protocol
HTTP is a pull protocol
SMTP requires each message, HTTP does not has to bother with
including the body to be in the ASCII conversion
seven-bit ASCII format
3. Compare TCP/IP and OSI model.
Ans.a.
Sr.
No
1
2
3
4
5
6
7
8
9
10
Open system Interconnection (OSI)
OSI provides layer functioning and
also defines functions of all the
layers.
In OSI model the transport layer
guarantees the delivery of packets.
Follows horizontal approach
OSI model has separate presentation
layer.
OSI is a general model.
Network layer of OSI model provide
both connection oriented and
connectionless service.
OSI model has the problem of fitting
the protocols in the model.
Protocols are hidden in OSI model
and are easily replaced as the
technology changes.
OSI model defines services, interfaces
and protocols very clearly and makes
clear distinction between them.
It has 7 layers
Transmission Control/Internet
Protocol (TCP/IP)
TCP/IP model is more based on
protocols and protocols are not
flexible with other layers.
In TCP/IP model the transport
layer does not guarantees the
delivery of packets.
Follows vertical approach.
TCP/IP model does not have a
separate presentation layer.
TCP/IP model cannot be used in
any other application.
Network layer of TCP/IP model
provides connectionless service.
TCP/IP model does not fit any
protocols.
In TCP/IP replacing protocols is
not easy.
In TCP/IP it is not clearly
separated its services, interfaces
and protocols.
It has 4 layers
4.Explain the need for layered architecture
1. To reduce design complexity, most networks are organized as a stack of
layers .
2. The number of layers, the name of each layer, and the function of each layer
differ from network to network.
3. The purpose of each layer is to offer services to the higher layers, shielding
those layers from the details of hoe the offered services are actually
implemented.
4. In a sense each layer is a kind of virtual machine offering certain services to
the layer above it.
5. The fundamental idea is that a particular piece of software (or hardware )
provides a service to its users but keeps the details of its internal state and
algorithm hidden from them.
5.Write short notes on
1.LAN:
2.WAN
3.VLAN
6. Explain connecting devices like hubs, repeaters, switches, bridges , router
and on which layers they operate.