Set - 3

Question 1 :

What are Stored procedures?

Answer :

A stored procedure i s named collection of SQL statements and procedural logic that is compiled, verified and stored in a server database. It is typically treated like any other database object. Stored procedures accept input parameters so that a single procedure can be used over the network by multiple clients using different input data. A single remote message triggers the execution of a collection of stored SQL statements. The results is a reduction of network traffic and better performance.


Question 2 :

What is wide-mouth frog?

Answer :

Wide-mouth frog is the simplest known key distribution center (KDC) authentication protocol.


Question 3 :

What is passive topology?

Answer :

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.


Question 4 :

What is region?

Answer :

When hierarchical routing is used, the routers are divided into what we call regions, with each router knowing all the details about how to route packets to destinations within its own region, but knowing nothing about the internal structure of other regions.


Question 5 :

What is virtual channel?

Answer :

Virtual channel is normally a connection from one source to one destination, although multicast connections are also permitted. The other name for virtual channel is virtual circuit.


Question 6 :

Difference between the communication and transmission?

Answer :

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 media.


Question 7 :

What is the difference between TFTP and FTP application layer protocols?

Answer :

The Trivial File Transfer Protocol (TFTP) allows a local host to obtain files from a remote host but does not provide reliability or security. It uses the fundamental packet delivery services offered by UDP.
The File Transfer Protocol (FTP) is the standard mechanism provided by TCP / IP for copying a file from one host to another. It uses the services offered by TCP and so is reliable and secure. It establishes two connections (virtual circuits) between the hosts, one for data transfer and another for control information.


Question 8 :

What are the advantages and disadvantages of the three types of routing tables?

Answer :

The three types of routing tables are fixed, dynamic, and fixed central. The fixed table must be manually modified every time there is a change. A dynamic table changes its information based on network traffic, reducing the amount of manual maintenance. A fixed central table lets a manager modify only one table, which is then read by other devices. The fixed central table reduces the need to update each machine's table, as with the fixed table. Usually a dynamic table causes the fewest problems for a network administrator, although the table's contents can change without the administrator being aware of the change.


Question 9 :

What is Beaconing?

Answer :

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.


Question 10 :

What does the Mount protocol do ?

Answer :

The Mount protocol returns a file handle and the name of the file system in which a requested file resides. The message is sent to the client from the server after reception of a client's request.


Question 11 :

What are Digrams and Trigrams?

Answer :

The most common two letter combinations are called as digrams. e.g. th, in, er, re and an. The most common three letter combinations are called as trigrams. e.g. the, ing, and, and ion.


Question 12 :

What is the HELLO protocol used for?

Answer :

The HELLO protocol uses time instead of distance to determine optimal routing. It is an alternative to the Routing Information Protocol.


Question 13 :

What is the minimum and maximum length of the header in the TCP segment and IP datagram?

Answer :

The header should have a minimum length of 20 bytes and can have a maximum length of 60 bytes.


Question 14 :

What do you meant by "triple X" in Networks?

Answer :

The function of PAD (Packet Assembler Disassembler) 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 the PAD and the network, called X.29. Together, these three recommendations are often called "triple X".


Question 15 :

What is attenuation?

Answer :

The degeneration of a signal over distance on a network cable is called attenuation.
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).


Question 16 :

What are the data units at different layers of the TCP / IP protocol suite?

Answer :

The data unit created at the application layer is called a message, at the transport layer the data unit created is called either a segment or an user datagram, at the network layer the data unit created is called the datagram, at the data link layer the datagram is encapsulated in to a frame and finally transmitted as signals along the transmission media.


Question 17 :

What is difference between ARP and RARP?

Answer :

The address resolution protocol (ARP) is used to associate the 32 bit IP address with the 48 bit physical address, used by a host or a router to find the physical address of another host on its network by sending a ARP query packet that includes the IP address of the receiver.
The reverse address resolution protocol (RARP) allows a host to discover its Internet address when it knows only its physical address.


Question 18 :

What is MAC address?

Answer :

The address for a device as it is identified at the Media Access Control (MAC) layer in the network architecture. MAC address is usually stored in ROM on the network adapter card and is unique.


Question 19 :

What is terminal emulation, in which layer it comes?

Answer :

Telnet is also called as terminal emulation. It belongs to application layer.


Question 20 :

What are the types of Transmission media?

Answer :

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.


Question 21 :

What are major types of networks and explain?

Answer :

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.


Question 22 :

What is SAP?

Answer :

Series of interface points that allow other computers to communicate with the other layers of network protocol stack.


Question 23 :

What is multicast routing?

Answer :

Sending a message to a group is called multicasting, and its routing algorithm is called multicast routing.


Question 24 :

What is the difference between routable and non- routable protocols?

Answer :

Routable protocols can work with a router and can be used to build large networks. Non-Routable protocols are designed to work on small, local networks and cannot be used with a router.


Question 25 :

What is REX?

Answer :

Request to Exit (REX) - A signal that informs the controller that someone has requested to exit from a secure area.


Question 26 :

What are the different type of networking / internetworking devices?

Answer :

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.
Bridges:
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 recipient and control congestion.
Routers:
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. Gateways: 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.