faqs on computer networks

[kiran2710]

1.How does the browser know to go to a certain IP address when you enter a domain like kyapoocha.com?

Answer :
It searches through local DNS cache, if nothing is there, it queries the ISP’s DNS server

2.What is Load balancing?


Answer :
If the number of incoming clients requests exceeds the number of processes in a server class, the TP Monitor may dynamically start new ones and this is called Load balancing

3.What is OLTP?

Answer :
In the transaction server, the client component usually includes GUI and the server components usually consists of SQL transactions against a database. These applications are called OLTP (Online Transaction Processing) OLTP Applications typically,
Receive a fixed set of inputs from remote clients. Perform multiple pre-compiled SQL comments against a local database.Commit the work and Return a fixed set of results.


4.What is Message Oriented Middleware (MOM)?

Answer :MOM allows general purpose messages to be exchanged in Client/Server system using message queues. Applications a communicate over networks by simply putting messages in the queues and getting messages from queues. It typically provides a very simple high level APIs to its services.

MOM’s messaging and queuing allow clients and servers to communicate across a network without being linked by a private, dedicated, logical connection. The clients and server can run at different times. It is a post-office like metaphor.

5.What is meant by Asymmetrical protocols?

Answer :

There is a many-to-one relationship between clients and server. Clients always initiate the dialog by requesting a service. Servers are passively awaiting for requests from clients.

6.What is Groupware server?

Answer :
Groupware addresses the management of semi-structured information such as text, image, mail, bulletin boards and the flow of work. These Client/Server systems have people in direct contact with other people.

7.What is Client/Server?

Answer :
Clients and Servers are separate logical entities that work together over a network to accomplish a task. Many systems with very different architectures that are connected together are also called Client/Server.

8.What is a File server?

Answer :
File servers are useful for sharing files across a network. With a file server, the client passes requests for file records over nerwork to file server.

9.What are called Fat clients and Fat servers?

Answer :If the bulk of the application runs on the Client side, then it is Fat clients. It is used for decision support and personal software.
If the bulk of the application runs on the Server side, then it is Fat servers. It tries to minimize network interchanges by creating more abstract levels of services.

10.What is Remote Procedure Call (RPC)?

Answer :
RPC hides the intricacies of the network by using the ordinary procedure call mechanism familiar to every programmer. A client process calls a function on a remote server and suspends itself until it gets back the results. Parameters are passed like in any ordinary procedure. The RPC, like an ordinary procedure, is synchoronous. The process that issues the call waits until it gets the results.
Under the covers, the RPC run-time software collects values for the parameters, forms a message, and sends it to the remote server. The server receives the request, unpack the parameters, calls the procedures, and sends the reply back to the client. It is a telephone-like metaphor.

11.What are the building blocks of Client/Server?

Answer :
The client ,The server and Middleware.


12.What is a TP Monitor?

Answer :
There is no commonly accepted definition for a TP monitor. According to Jeri Edwards’ a TP Monitor is “an OS for transaction processing”.
TP Monitor does mainly two things extremely well. They are Process management and Transaction management.
They were originally introduced to run classes of applications that could service hundreds and sometimes thousands of clients. TP Monitors provide an OS - on top of existing OS - that connects in real time these thousands of humans with a pool of shared server processes.

13.What are Super servers?

Answer :
These are fully-loaded machines which includes multiprocessors, high-speed disk arrays for intervive I/O and fault tolerant features.

14.What is a Web server?

Answer :
This new model of Client/Server consists of thin, protable, “universal” clients that talk to superfat servers. In the simplet form, a web server returns documents when clients ask for them by name. The clients and server communicate using an RPC-like protocol called HTTP.

15.What is a Database Server?

Answer :
With a database server, the client passes SQL requests as messages to the database server. The results of each SQL command are returned over the network. The server uses its own processing power to find the request data instead of passing all the records back to the client and then getting it find its own data. The result is a much more efficient use of distributed processing power. It is also known as SQL engine.

16.What is an Object server?

Answer :
With an object server, the Client/Server application is written as a set of communicating objects. Client object communicate with server objects using an Object Request Broker (ORB). The client invokes a method on a remote object. The ORB locates an instance of that object server class, invokes the requested
method and returns the results to the client object. Server objects must provide support for concurrency and sharing. The ORB brings it all together.

17.What is anonymous FTP and why would you use it?

Answer :
Anonymous FTP enables users to connect to a host without using a valid login and password. Usually, anonymous FTP uses a login called anonymous or guest, with the password usually requesting the user’s ID for tracking purposes only. Anonymous FTP is used to enable a large number of users to access files on the host without having to go to the trouble of setting up logins for them all. Anonymous FTP systems usually have strict controls over the areas an anonymous user can access.

18. What is a DNS resource record?

Answer :
A resource record is an entry in a name server’s database. There are several types of resource records used, including name-to-address resolution information. Resource records are maintained as ASCII files.

19.Explain the function of Transmission Control Block

Answer :
A TCB is a complex data structure that contains a considerable amount of information about each connection.

20.What is virtual path?

Answer :
Along any transmission path from a given source to a given destination, a group of virtual circuits can be grouped together into what is called path.

[sangeethadutta]

nice info frnd...........