1) Write the categories of networks

2) Define a network

3) What is FDDIFiber distributed data interfaceFDDI is a fiber optic based counter rotating token ring

architectureFeatures :

Number of stations : up to 1000 connections are allowed Total fiber path : up to 200 km of total fiber leanth is allowed Data transmission media : FFDI specifics multi mode optical

fiber 4) Give the basic building blocks of network

5) Define Framing

6) What is meant by 1 –persistent CSMA

7) What is a Bridge

8) A network with bandwidth of 10 Mbps can pass only an average of 12,000frames per minute with each frame carrying an average of 10,000 bits. What is the throughput of this network?

9) Define computer network?

Computer networks provide general cost effective , fair and robust connectivity among large number of computer .computer network is designed around the concept of layered protocols or functions .for exchange of data between computer , terminals or other data processing device ,there is data path between two computers ,either directly or via a communication network

UNIT - II

1) Differentiate ARP and RARP AM 2011

ARP RARPIt operates at high level It operates at low level

It do not require direct address to the the network which makes it difficult for an application programmer to build a server

It require direct address to the the network which makes it difficult for an application programmer to build a server

It fully utilises the capability of a network

It does not fully utilises the capability of a network

2) Give the CIDR notation for Class A, B and C AM 2011

Class A=/8,

Class B=/16,

Class c=/24

3) What is internetworking ND 2011, ND 2012, ND 2013

The LANs and switched data sub networks are interconnected to allow the user to communicate across several sub networks. This extended network so formed is called INTERNETWORK.

This process is called as internetworking. The internetwork devices such as bridges, routers are used to

connect two or more LANs and subnets It provides a link between a network It provides routing and delivery of data between process on

different network

4) What is IPV6 ND 2011, ND 2012, ND 2013

IPV6:

It is a new notation for writing 16-byte address They are written as eight groups of four hexadecimal digits with

colons between the groups like80000: 0000 : 0000 : 0000 : 0123 : 4567 : 89AB : CDEF

5) Why are the protocols needed AM 2012

Protocols are the rules that govern the network communication Design complexity is reduced because of the series layer. In networks, communication occurs between the entities in

different systems. Two entities cannot just send bit streams to each other and expect to be understood. For communication, the entities must agree on a protocol. A protocol is a set of rules thatgovern data communication.

6) What is the use of IP Address AM 2012

An IP address has a fixed length of 32 bits. IP addresses are unique. Two devices on the internet can never have the same address at

the same time. The address structure has two level

7) What are the uses of internetwork routing AM 2013

An internet is divided into autonomous system. An autonomous system is a group of networks and routers under

the authority of a single administration

ROUTING BETWEEN AUTONOMOUS SYSTEM IS CALLED INTERDOMAIN ROUTING

8) What is the purpose of subnetting AM 2013.

To allow a single network address to span multiple physical networks is called SUBNETTING or SUBNET ADDRESSING or SUBNET ROUTING.

It is a required part of IP addressing. If each router on internet needed to know about each existing

physical network, routing tables would be impossibly huge. This is physical overhead on the router. To solve this type of problem, the subnet addressing method is used.

UNIT- III

1) Draw the datagram format of UDP?(AM 2011)

UDP is a simple, connectionless protocol. It provides no reliability; it simply sends data to the IP layer,to use UDP, an application associates itself with a "transport address"

a. for UDP, a transport address is a combination of an IP address and a port number

b. a port number is a 16-bit number that uniquely identifies the application using UDP.

2) Define flow control?( AM 2011)

 The process of adjusting the flow of data from one device to another to ensure that the receiving device can handle all of the incoming data. This is particularly important where the sending device is

capable of sending data much faster than the receiving device can receive it.

In programming, the statements and other constructs that control the order in which operations are executed. For example, commonlooping statements such as fornext and while are known as flow control statements. Branching statements, such as if then are also part of a programming language flow control mechanism.

3) What is queuing?( ND 2011)

Queuing is the process of  lining up jobsfor a computer or device.  In programming, a queue is a data structure in which elements are removed in the same order they were entered. This is often referred to as FIFO (first in, first out). In contrast, a stack is a data structure in which elements are removed in the reverse order from which they were entered. This is referred to as LIFO (last in, first out).

Different Queuing methods

First in First Out Priority Queuing Round robin Weighted Fair queuing

4) Define congestion ND 2011, ND 2012

Congestion is a state occurring in part of a network when the message traffic is so heavy that it slows down network response time.

Congestion in network may occurs if the load on the network ;the number of the packets sent to the network is greater than the capacity of the network.

5) What is Client Process?(AM 2012)Client Process is the process of clientcalls the Sockets function to create socket. It then calls sendto function and pass socket address of the server location of the buffer from which UDP can get the data to make the datagram. Then the client recvfrom function call that block until the reply arrives from the server.

6) What are the 2 Multiplexing Strategies used in Transport Layer?(AM 2012)

Upward multiplexing Downward multiplexing

\7) Give the functions of ARP?(ND 2012)

Address Resolution protocol , a network layer protocol used to convert an IP address into a physical address (called a DLC address), such as an Ethernet address.

A host wishing to obtain a physical address broadcasts an ARP request onto the TCP/IP network. The host on the network that has the IP address in the request then replies with its physical hardware address

8) List any four QoS parameters?(AM 2013) Reliability Delay Jitter Bandwidth

9) Differentiate flow control from congestion control?( AM 2013)

FLOW CONTROL CONGESTION CONTROL

Flow control is an end to end mechanism that controls the traffic between a sender and a receiver, when a fast sender is transmitting data to a slow receiver.

Flow control refers to mechanisms used to handle the transmission between a particular sender and a receiver.

Congestion control is a mechanism that is used by a network to control congestion in the network.

Congestion control can be seen as a mechanism that makes sure that an entire network can handle the traffic that is coming to the network.

10) What is Flow control?( ND 2013)The process of adjusting the flow of data from one device to another to ensure that the receiving device can handle all of the incoming data. This is particularly important where the sending

device is capable of sending data much faster than the receiving device can receive it.

This process is known as flow control

11) Define Slow Start algorithm?( ND 2011)

Slow-start algorithm is part of the congestion control in TCP, designed to avoid sending more data than the network is capable of transmitting.

Slow-start algorithm works by increasing the TCP Window by one segment for each acknowledged segment. This behavior effectively doubles the TCP Window size each round trip of the network.

The algorithm continues increasing until this "congestion window" (cwnd) reaches the size of the receivers advertised TCP Receive Window (RWIN), or until packet loss occurs.

UNIT - IV

1) What is cipher text AM 2011In cryptography, cipher text (or cyphertext) is the result of encryption performed on plaintext using an algorithm, called a cipher. Cipher text is also known as encrypted or encoded information because it contains a form of the original plaintext that is unreadable by a human or computer without the proper cipher to decrypt it. Decryption, the inverse of encryption, is the process of turning cipher text into readable plaintext.

2) List out the two modes of IP security AM 2011

Short for IP Security, a set of protocols developed by the IETF to support secure exchange of packets at the IP layer. IPsec has been deployed widely to implement Virtual Private Networks (VPNs).IPsec supports two encryption modes: Transport and Tunnel. Transport mode encrypts only the data portion (payload) of each packet, but leaves the header untouched. The more secure Tunnel mode encrypts both the header and the payload. On the receiving side, an IPSec-compliant device decrypts each packet.

3) Define cryptography ND 2011, ND 2012, AM 2013

Cryptography is the art of protecting information by transforming it (encrypting it) into an unreadable format, called cipher text. Only those who possess a secret key can decipher (or decrypt) the message into plain text. Encrypted messages can sometimes be broken by cryptanalysis, also called code breaking, although modern cryptography techniques are virtually unbreakable.

4) What is PGP ND 2011, ND 2012, AM 2013, ND 2013

Pretty Good Privacy (PGP) is a data encryption and decryption computer program that provides cryptographic privacy and authentication for data communication. PGP is often used for signing, encrypting, and decrypting texts, e-mails, files, directories, and whole disk partitions and to increase the security of e-mail communications. PGP encryption uses a serial combination of hashing, data compression, symmetric-key cryptography, and finally public-key cryptography; each step uses one of several supported algorithms. 

5) Define security in networking AM 2012

Network security consists of the provisions and policies adopted by a network administrator to prevent and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources. Network security involves the authorization of access to data in a network, which is controlled by the network administrator. Users choose or are assigned an ID and password or other authenticating information that allows them access to information and programs within their authority. Network security covers a variety of computer networks, both public and private, that are used in everyday jobs conducting transactions and communications among businesses, government agencies and individuals. 

6) What is Symmetric key algorithm AM 2012

Symmetric-key algorithms are a class of algorithms for cryptography that use the same cryptographic keys for both encryption of plaintext and decryption of cipher text. The keys may be identical or there may be a simple transformation to go between the two keys. The keys, in practice, represent a shared secret between two or more parties that can be used to

maintain a private information link. This requirement that both parties have access to the secret key is one of the main drawbacks of symmetric key encryption, in comparison to public-key encryption

7) What is MPEG ND 2013

Short for Moving Picture Experts Group, and pronounced m-peg, is a working group of the ISO. The term also refers to the family of digital video compression standards and file formats developed by the group. MPEG generally produces better-quality video than competing formats, such as Video for Windows, Indeo and QuickTime. MPEG files previously on PCs needed hardware decoders (codecs) for MPEG processing. Today, however, PCs can use software-only codecs including products from Real Networks, QuickTime or Windows Media Player.

Unit – V

1.What is DNS (AM 2011, AM 2013)

The DNS translates Internet domain and host names to IP addresses. DNS automatically converts the names we type in our Web browser address bar to the IP addresses of Web servers hosting those sites.DNS implements a distributed database to store this name and address information for all public hosts on the Internet. DNS assumes IP addresses do not change (are statically assigned rather than dynamically assigned).

2.How is HTTP related to WWW AM 2011

The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, hypermedia information systems.[1] HTTP is the foundation of data communication for the World Wide Web.Hypertext is structured text that uses logical links (hyperlinks) between nodes containing text. HTTP is the protocol to exchange or transfer hypertext. The standards development of HTTP was coordinated by the Internet Engineering Task Force (IETF) and the World Wide Web Consortium (W3C), culminating in the publication of a series of Requests for Comments (RFCs), most notably RFC 2616 (June 1999), which defines HTTP/1.1, the version of HTTP in common use.

3.What is HTTP ND 2011, ND 2012

The Hypertext Transfer Protocol - provides a standard for Web browsers and servers to communicate. The definition of HTTP is a

technical specification of a network protocol that software must implement. HTTP is an application layer network protocol built on top of TCP. HTTP clients (such as Web browsers) and servers communicate via HTTP request and response messages. The three main HTTP message types are GET, POST, and HEAD.HTTP utilizes TCP port 80 by default, though other ports such as 8080 can alternatively be used.

4.List multimedia applications ND 2011

Multimedia uses computers to present text, audio, video, animation, interactive features, and still images in various ways and combinations made possible through the advancement of technology. By combining media and content, those interested in multimedia can take on and work with a variety of media forms to get their content across. This is an exciting new field for those interested in computers, technology, and creative career options. Multimedia can be accessed through computers or electronic devices and integrates the various forms together. One example of multimedia would be combining a website with video, audio, or text images.

5.Define HTML AM 2012

HTML is made up of elements (often called tags) that build the contents of a web page. The differences between HTML and other programming languages include:HTML is not compiled. It is written and used without any changes being done to it. I starts out a text file, and is still a text file when a browser or user agent interprets it.HTML is human readable. While some other programing languages can be read by people (and not just machines), many times you have to learn the language to really understand it. In comparison, most HTML beginners can at least guess what an <img> tag does, for example.

6.What are OVerlay networks ND 2012, AM 2013

Distributed hash tables (DHTs), such as KAD and other protocols based on the Kademlia algorithm, for example.JXTA XMPP: the routing of messages based on an endpoint Jabber ID (Example: nodeId_or_userId@domainId\resourceId) instead of by an IP Address Many peer-to-peer protocols including Gnutella, Gnutella2, Freenet, I2P and Tor. (Examples: Limewire, Shareaza, μTorrent, Tribler, etc.) PUCC Solipsis: a France Télécom system for massively shared virtual world HyParView: a highly robust unstructured overlay for gossip broadcast

Overlay network protocols based on UDP/IP include: Real Time Media Flow Protocol - Adobe Flash

7.State the advantages of DNS AM 2013

DNS-based redirection has several advantages. The most visible one is that it achieves transparency without losing scalability. It is transparent because the clients are obliged to use the addresses provided by the authoritative DNS server, and cannot establish whether these addresses belong to the home machine of the service or to any of its replicas. DNS as a distributed name resolution service proved to be very efficient, even though the amount of people using it has increased tremendously with the growth of the Internet. Another vital advantage of using DNS to redirect clients is that it is a natural way of informing the clients about the service addresses. It is used by many existing network services, and is very likely to be used by those to come as well.

8.State tell why TELNET uses network virtual terminal AM 2012

Telnet uses an approach similar to the analogy described above for dealing with its problem of hardware and software compatibility. Rather than having terminals and hosts communicate using their various native “languages”, all Telnet clients and servers agree to send data and commands that adhere to a fictional, “virtual” terminal type call the Network Virtual Terminal (NVT). The NVT defines a set of rules for how information is formatted and sent, such as character set, line termination, and how information about the Telnet session itself is sent. Each Telnet client running on a terminal understands both its native language and NVT. When information is entered by the user on his or her local terminal, it is converted to NVT for transmission over the network in NVT form. When the Telnet server receives this information, it translates it from NVT to the format that the remote host expects to receive it. The identical process is performed for transmissions from the server to the client, in reverse.