How to resize a partition in Windows Vista

Gxtechno Tags: resize, partition, windows, vista, shrink, extand

The third party programs such as Partition Magic, GParted etc. don’t work on Windows Vista, some of fellas may be wondering how to resize partitions without losing any data. So don’t go anywhere and don’t look for third party tools your vista can manage this problem by itself. How? Look at this.
To resize a partition with Windows Vista, follow these steps:
Be sure to back up any valuable information, because there is a slight chance that data can be lost when dealing with partitions.
1) Click on the Start menu
2) Right click on Computer and click on Manage

3) You may get a User Account Control dialog here; just click Continue
4) In the left pane, open up the Storage category and click on Disk Management

5) Here, you will find your partitions for your disks. Right click on the partition you’d like to modify.

6) Click on Extend Volume or Shrink Volume to extend or shrink the selected partition.
Special Thnx to Vista Rewired for the article.

DVI (Digital Visual Interface) Technology

The DVI is a video interface standard designed to provide very high visual quality on digital display devices such as flat panel LCD computer displays and digital projectors.

The DVI interface uses a digital protocol in which the desired illumination of pixels is transmitted as binary data. When the display is driven at its native resolution, it will read each number and apply that brightness to the appropriate pixel. In this way, each pixel in the output buffer of the source device corresponds directly to one pixel in the display device, whereas with an analog signal the appearance of each pixel may be affected by its adjacent pixels as well as by electrical noise and other forms of analog distortion.

Read more from Multimedia System By:- John F.Koegel Buford. Page No.181-185

Collaborative Library Design

GXTechno Tags: collaborative, learning, library

Time to Revolutionize Traditional Library Design into Collaborative Library

Today is the world of information sharing and library is the best part to work on information. But today library design is not enough to fit into the requirement of collaborative learning, isn’t it?

Now collaborative learning is a very common approach to share knowledge. With the rise of internet and social network sites like blogs, orkuts, newsgroups, youtube etc. we are witnessing a major shift in the ways students approach and use information. They no longer merely consume and download information only; increasingly, they create and participate in it. They are social creatures in every way that past generations were and in some new ways, sharing information digitally and using each other as sounding boards. They value social experiences that blend communication and learning.

The libraries should be set according to the students need. Libraries first incarnation of the information commons resembled large, fixed computer labs that were, by the large, hardware centered. This should be arranging by the layering of new technology with the old. For instance students’ can venture out with their laptops or portable devices to peruse the book stacks or visit the library’s special collections.

What more the Traditional Library required?

Every time when me and my friends think about today’s culture of learning we found some loose corners in traditional library space to work on like:

Library Equipments

Collaborative learning brings together a wide range of elements to faster student learning in new and creative ways. Me and my friend watching the library with wide screen high-definition monitors, rotating screen projectors, laptop docking stations, wi-fi internet facilities. Where the students are not only studying books and article but actively participating online, making own definitions and broad collaborative discussions on topics and their interest of areas.

Comfortable Spacing

It should be design for many types of learners, not just one. The traditional library furniture wooden tables and chairs also facilitate collaboration, but there should be different types of seating spaces as well. Like sofas, large upholstered chairs, multi position chairs, task chairs, and other furnishings are found throughout the space. The goal is to make learners comfortable.

Inspiring Environment

The space should feel dynamic; with artwork, paintings, kinetic sculptures, ceramics and other art can be display in and around the commons to inspire learners. The furnishing, layout and design should present a uniform and consistent vision of functionality, sophistication, and creativity.

Beginning to think of the whole campus, as a learning space. Shred spaces devices and software can expand a single laptop display to multiple widescreen monitors so that everyone seated around a table or workspace becomes part of the study. Add a wireless keyboard and mouse, laser pen and pointer, and everyone has the opportunity for hands on input. Again the goal is the make learners comfortable. Holding focus groups or simply asking learners can help determine the appropriate features.

The information commons itself must adapt and evolve to meet changing expectations and technological capabilities. How well do these environments currently support social learning and promote collaborative work? Do they encourage creativity and discovery and inspire learners?

MPEG VIDEO

GenXTechno Tags: mpeg, compression, i frame, p frame, b Frame

Although the MPEG-1 standard is quite flexible, the basic algorithms have been tuned to work well at data rates from 1 to 1.5 Mbps, at resolutions of about 350 by 250 Pixels at picture rates of up to 25 or 30 pictures per second. MPEG-1 codes progressively-scanned images and does not recognized the concept of interlace, interlaced source video must be converted to a non-interlace format prior to encoding. The format of the coded video allows forward play and pause, typical coding and decoding methods allow random access, fast forward and reverse play also, the requirements for these functions are very much application dependent and different encoding techniques will include varying levels of flexibility to account for these functions. Compression of the digitized video comes from the use of several techniques: Sub sampling of the chroma information to match the human visual system, differential coding to exploit spatial redundancy, motion compensation to exploit temporal redundancy, Discrete Cosine Transform (DCT) to match typical image statistics, quantization, variable length coding, entropy coding and use of interpolated pictures.
Algorithm Structure and Terminology
The MPEG hierarchy is arranged into layers (Figure 1).

This layered structure is designed for flexibility and management efficiency, each layer is intended to support a specific function i.e. the sequence layer specifies sequence parameters such as picture size, aspect ratio, picture rate, bit rate etcetera , whereas the picture layer defines parameters such as the temporal reference and picture type. This layered structure improves ro-bustness and reduces susceptibility to data corruption.
For convenience of coding, macroblocks are divided into six blocks of component Pixels four luma and two chroma (Cr and Cb) (Figure 2).

Blocks are the basic coding unit and the DCT is applied at this block level. Each block contains 64 component Pixels arranged in an 8x8 array (Figure 3).

There are four picture types : I pictures or INTRA pictures, which are coded without reference to any other pictures; P pictures or PREDICTED pictures which are coded using motion compensation from previous picture; B pictures or BIDIRECTIONALLY predicted pictures which are coded using interpolation from a previous and a future picture and D pictures or DC pictures in which only the low frequency component is coded and which are only intended for fast forward search mode. B and P pictures are often called Inter pictures. Some other terminology that is often used are the terms M and N, M+1 represents the number of frames between successive I and P pictures whereas N+1 represents the number of frames between successive I pictures. M and N can be varied according to different applications and requirements such as fast random access.
A typical coding scheme will contain a mix of I,P and B pictures. A typical scheme will have an I picture every 10 to 15 pictures and two B pictures between succesive I and P pictures (Figure 4).

Prediction (P Frame)
The predicted picture is the previous picture modified by motion compensation. Motion vectors are calculated for each macroblock. The motion vector is applied to all four luminance blocks in the macro block. The motion vector for both chrominance blocks is calculated from the luma vector. This technique relies upon the assumption that within a macroblock the difference between successive pictures can be represented simply as a vector transform (i.e. there is very little difference between successive pictures, the key difference being in position of the Pixels) (Figure 5).

Interpolation ( I Frame)
Interpolation (or bidirectional prediction) generates high compression in that the picture is represented simply as an interpolation between the past and future I or P pictures (again this is performed on a Pictures are not transmitted in display order but in the order in which the decoder requires them to decode the bitstream (the decoder must of course have the reference picture(s) before any interpolated or predicted pictures can be decoded).

 

Thnx to:-Ref:-SGS-THOMSON Microelectronics

Different Sound Spectrum

GenXTechno Tags: stereophonic, quardraphonic, sound

Stereophonic Sound

Stereophonic sound, commonly called stereo, is the reproduction of sound using two or more independent audio channels through a symmetrical configuration of loudspeakers in such a way as to create the impression of sound heard from various directions, as in natural hearing. It is often contrasted with monophonic or "mono" sound, where audio is in the form of one channel, often centered in the sound field (analogous to a visual field).

Recording methods

X-Y technique: intensity stereophony

A-B technique: time-of-arrival stereophony

M/S technique: Mid/Side stereophony

Near-coincident technique: mixed stereophony

Quadraphonic sound

Quadraphonic sound consists of 4 channels, right front, left front, right rear, and left rear. Quad albums and equipment starting to show up in the early '70s, and as you can probably imagine, quad albums came in primarily 3 different formats, 8 track, record, and open reel, the first 2 being the most common. The stereo 8 track, like the name says, has 8 tracks, making 4 programs (4 programs * 2 channels = 8 tracks). The quad 8 track used the same number of tracks (again, like the name says), and has only 2 programs (2 programs * 4 channels = 8 tracks). One more difference to keep in mind (one of the many reasons quad didn't stay around) is that when the number of programs is cut in half, so is the time, meaning quad 8 tracks had to have more tape to get the same play time as their stereo counterparts.
The stereo record (like all records) has a 2 sided "V" shaped grove, in which the needle rides. The stereo (and quad) records have that groove cut at a 90 degree angle, so each side is 45 degrees to the surface of the record, and each of the 2 channels in recorded it's own side of the groove. Since it isn't possible to have a groove with more than two sides that will play back right or be compatible with existing equipment, quad records use encoding and decoding to take the 4 channels of sound and make them into 2 channels to store on the record, and to then separate the 4 channels back out when it's played. Either matrixing or modulation of rear channels onto high frequencies is used to make the original 4 channels fit onto 2 (There is more about this below).

The Fourier method

GenXTechno Tags: audio, encoding, foruier

Introduction To Fourier method
The temporal analysis of a signal with the Fourier method (spectral analysis) allows us to highlight the main components of a signal. In the musical world, the spectral analysis allows us to identify different instruments: each instrument has its own particular tone.
We can "observe" the sound, which is nothing other than a movement of matter. The resonance frequencies in particular are very characteristic. A resonance vibration (or oscillation) is characterized on a chord by a succession of antinodes and nodes, i.e. of points where the vibrations have a maximal or null displacement respectively.

• The sound emitted by a diapason (A 440 Hz) corresponds to a pure sound.
• The sound of a guitar has several harmonics.
• The spectrum of a cymbal is much more complex.

When studying a signal, a sound for instance, the spectrum allows us to determine the characteristics of this signal : frequency and intensity.
In the case of the Sun or stars, which are located millions of kilometers away, how can we observe the interior of these objects, for which the temperature exceeds one million degrees?
We must listen, not try to only see, and use the sound waves.

• The light allows us to explore the surface of an object, it does not penetrate very much in depth,
• The sound gives information on the deeper layers, it propagates inside the object.

Subband Coding

mGenXTechno Tags: audio, encoding, subband, coding

Introduction to Subband Coding
Sub-Band Coding (SBC) is a powerful and general method of encoding audio signals efficiently. Unlike source specific methods (like LPC, which works only on speech), SBC can encode any audio signal from any source, making it ideal for music recordings, movie soundtracks, and the like. MPEG Audio is the most popular example of SBC. This document describes the basic ideas behind SBC and discusses some of the issues involved in its use.
Basic Principles
SBC depends on a phenomenon of the human hearing system called masking. Normal human ears are sensitive to a wide range of frequencies. However, when a lot of signal energy is present at one frequency, the ear cannot hear lower energy at nearby frequencies. We say that the louder frequency masks the softer frequencies. The louder frequency is called the masker.
The source output can be decomposed into its constituent parts using digital filters.
Each of these constituent parts will be different bands of frequencies which make up the source.
A compression approach where digital filters are used to separate the source output into different bands of frequencies.
àEach part then can be encoded separately.
Filters
A filter is system that isolates certain frequencies.
(i) Low Pass Filters
(ii) High Pass Filters
(iii) Band Pass Filters
Filter Characteristics

• ØMagnitude Transfer Function : the ratio of the magnitude of the input and output of the filter as a function of frequency.

• fo = Cutoff Frequency.

Digital Filters
Components between frequencies f1and f2 then,
Sampling and Nyquist rule :
If fo is the highest frequency of the signal then the sampling rate > 2fo per second can accurately represent the continuous signal in digital form.
Extension of Nyquist rule:
For signal with frequency
sampling rate = 2(f2 — f1) per second.
Violation of Nyquist rule:
Distortion due to aliasing.



Subband Coding Algorithm



Above picture shows pyramid decomposition of an image where encoding is shown on the left and decoding is shown on the right. The operators D and I correspond to Decimation and interpolation operators, respectively. For example, D produces an N/2 × N/2 image from an N × N original, while I interpolate an N × N image based on an N/2 × N/2 original.
Analysis
Source output --> analysis filter bank--> sub-sampled-->encoded.
Analysis Filter Bank

• The source output is passed through a bank of filters.
• his filter bank covers the range of frequencies that make up the source output.
• The passband of each filter specifies each set of frequencies that can pass through.

Decimation

• The outputs of the filters are subsampled thus reducing the number of samples.
• The justification for the subsampling is the Nyquist rule and its extension justifies this downsampling.
• The amount of decimation depends on the ratio of the bandwidth of the filter output to the filter input.

Encoding

• The decimated output is encoded using one of several encoding schemes, including ADPCM, PCM, and vector quantization.

Quantization and Coding
Selection of the compression scheme will be done based on the characteristic exhibited by the subbands.
Along with the selection of the compression scheme, the allocation of bits between the subbands is an important design parameter. This is what determines the quantizer parameters.

• Selection of the compression scheme
• Allocation of bits between the subbands

-->allocate the available bits among the subbands according to measure of the information content in each subband.
Bit Allocation
This bit allocation procedure significantly impacts quality of the final reconstruction.
Minimizing the distortion i.e. minimizing the reconstruction error drives the bit allocation procedure.
Different subband-->different amount of information.
Bit allocation procedure can have a significant impact on the quality of the final reconstruction
Synthesis

• Quantized and Coded coefficients are used to reconstruct a representation of the original signal at the decoder.

Encoded samples from each subband—>decoded—>upsampled--> bank of reconstruction filters-->outputs combined--> Final reconstructed output

Application
The subband coding algorithm has applications in -

• Speech Coding
• Audio Coding
• Image Compression

Firewalls

GenXTechno Tags: firewall, proxy, server, filter

Internet firewalls are intended to keep the flames of Internet hell out of your private LAN. Or, to keep the members of your LAN pure and chaste by denying them access the all the evil Internet temptations.
The first computer firewall was a non routing UNIX host with connections to two different networks. One network card connected to the Internet and the other to the private LAN. To reach the Internet from the private network, you had to logon to the firewall (Unix) server. You then used the resources of the system to access the Internet. For example, you could use X−windows to run Netscape's browser on the firewall system and have the display on your work station. With the browser running on the firewall it has access to both networks.


Firewall Politics
You shouldn't believe a firewall machine is all you need. Set policies first. Firewalls are used for two purposes.
1. to keep people (worms / crackers) out.
2. to keep people (employees / children) in.

Create a security policy is simple.
1. describe what you need to service
2. describe the group of people you need to service
3. describe which service each group needs access to
4. for each service group describe how the service should be keep secure
5. write a statment making all other forms of access a vialation

Types of Firewalls

There are two types of firewalls.
1. Filtering Firewalls − that block selected network packets.
2. Proxy Servers (sometimes called firewalls) − that make network connections for you.

Packet Filtering Firewalls

Packet Filtering is the type of firewall built into the Linux kernel.
A filtering firewall works at the network level. Data is only allowed to leave the system if the firewall rules allow it. As packets arrive they are filtered by their type, source address, destination address, and port information contained in each packet.
Filtering firewalls do not provide for password controls. User can not identify themselves. The only identity a user has is the IP number assigned to their workstation. This can be a problem if you are going to use DHCP (Dynamic IP assignments). This is because rules are based on IP numbers you will have to adjust the rules as new IP numbers are assigned.

Proxy Servers

Proxies are mostly used to control, or monitor, outbound traffic. Some application proxies cache the
requested data. This lowers bandwidth requirements and decreases the access the same data for the next user. It also gives unquestionable evidence of what was transferred.
There are two types of proxy servers.
1. Application Proxies − that do the work for you.
2. SOCKS Proxies − that cross wire ports.

Application Proxy

The best example is a person telneting to another computer and then telneting from there to the outside world. With a application proxy server the process is automated. As you telnet to the outside world the client send you to the proxy first. The proxy then connects to the server you requested (the outside world) and returns the data to you.
Because proxy servers are handling all the communications, they can log everything they (you) do. For HTTP (web) proxies this includes very URL they you see. For FTP proxies this includes every file you download. They can even filter out "inappropriate" words from the sites you visit or scan for viruses.
Application proxy servers can authenticate users. Before a connection to the outside is made, the server can ask the user to login first. To a web user this would make every site look like it required a login.

SOCKS Proxy

A SOCKS server is a lot like an old switch board. It simply cross wires your connection through the system to another outside connection.
Most SOCKS server only work with TCP type connections. And like filtering firewalls they don't provide for user authentication. They can however record where each user connected to.

Digital Signature

GenXTechno Tags: digital, signature, certificate, crc

A digital signature is basically a way to ensure that an electronic document (e-mail, spreadsheet, text file, etc.) is authentic. Authentic means that you know who created the document and you know that it has not been altered in any way since that person created it.

There are several ways to authenticate a person or information on a computer:

• 
  
  Password - The use of a user name and password provide the most common form of authentication. You enter your name and password when prompted by the computer. It checks the pair against a secure file to confirm. If either the name or password do not match, then you are not allowed further access.
• 
  
  Checksum - Probably one of the oldest methods of ensuring that data is correct, checksums also provide a form of authentication since an invalid checksum suggests that the data has been compromised in some fashion. A checksum is determined in one of two ways. Let's say the checksum of a packet is 1 byte long, which means it can have a maximum value of 255. If the sum of the other bytes in the packet is 255 or less, then the checksum contains that exact value. However, if the sum of the other bytes is more than 255, then the checksum is the remainder of the total value after it has been divided by 256. Look at this example:

Byte 1	Byte 2	Byte 3	Byte 4	Byte 5	Byte 6	Byte 7	Byte 8	Total	Checksum
212	232	54	135	244	15	179	80	1151	127

1151 divided by 256 equals 4.496 (round to 4) Multiply 4 X 256 which equals 024 1151 minus 1024 equals 127

• 
  
  CRC (Cyclic Redundancy Check) - CRCs are similar in concept to checksums but they use polynomial division to determine the value of the CRC, which is usually 16 or 32 bits in length. The good thing about CRC is that it is very accurate. If a single bit is incorrect, the CRC value will not match up. Both checksum and CRC are good for preventing random errors in transmission, but provide little protection from an intentional attack on your data. The encryption techniques below are much more secure.
• 
  
  Private key encryption -Private key means that each computer has a secret key (code) that it can use to encrypt a packet of information before it is sent over the network to the other computer. Private key requires that you know which computers will talk to each other and install the key on each one. Private key encryption is essentially the same as a secret code that the two computers must each know in order to decode the information. The code would provide the key to decoding the message. Think of it like this. You create a coded message to send to a friend where each letter is substituted by the letter that is second from it. So "A" becomes "C" and "B" becomes "D". You have already told a trusted friend that the code is "Shift by 2". Your friend gets the message and decodes it. Anyone else who sees the message will only see nonsense.
• 
  
  Public key encryption - Public key encryption uses a combination of a private key and a public key. The private key is known only to your computer while the public key is given by your computer to any computer that wants to communicate securely with it. To decode an encrypted message, a computer must use the public key provided by the originating computer and it's own private key.

The key is based on a hash value. This is a value that is computed from a base input number using a hashing algorithm. The important thing about a hash value is that it is nearly impossible to derive the original input number without knowing the data used to create the hash value. Here's a simple example:

Input number	Hashing algorithm	Hash value
10667	Input # x 143	1525381

You can see how hard it would be to determine that the value of 1525381 came from the multiplication of 10667 and 143. But if you knew that the multiplier was 143, then it would be very easy to calculate the value of 10667. Public key encryption is much more complex than this example but that is the basic idea. Public keys generally use complex algorithms and very large hash values for encrypting: 40-bit or even 128-bit numbers. A 128-bit number has a possible 2¹²⁸ different combinations. That's as many combinations as there are water molecules in 2.7 million olympic size swimming pools. Even the tiniest water droplet you can image has billions and billions of water molecules in it!

• 
  
  Digital certificates - To implement public key encryption on a large scale, such as a secure Web server might need, requires a different approach. This is where digital certificates come in. A digital certificate is essentially a bit of information that says the Web server is trusted by an independent source known as a Certificate Authority. The Certificate Authority acts as the middleman that both computers trust. It confirms that each computer is in fact who they say they are and then provides the public keys of each computer to the other.

Encryption

GenXTechno Tags: asymmetric, symmetric, encryption, keys, public, private

Data encryption provides a way for you to protect your data from prying eyes. It also prevents unauthorized users from transmitting confidential data to the wrong party or performing any modifications to the data.
Data encryption works through a coding process to prevent documents, email messages, and other types of information from being accessed by unauthorized users. In an age of increased use of PC technology and sophisticated hackers, it is very easy for others to intercept your messages and read confidential documents.
“Encryption is the conversion of data into a form, called a ciphertext that cannot be easily understood by unauthorized people. Decryption is the process of converting encrypted data back into its original form, so it can be understood.”

Symmetric Encryption

Symmetric encryption involves transmission of a file through the program you are using. This type of encryption creates a key that jumbles up the file for emailing to the person on the receiving end. In order for the recipient to view the file, the sender must forward a separate decoding key which unscrambles the file so the recipient can view and read it.
The only problem with this type of data encryption is it is possible for someone to intercept the file as well as the decoding key during transmission.

Asymmetric Encryption

This type of data encryption is more secure than symmetric encryption because there are two keys involved with decoding the data, the public key and the private key. When the sender forwards a file, they do so by encrypting it with the recipient's public key. Once the recipient receives the file they access the data by using their private key. The process is much more secure but also takes longer to transmit.
Both types of encryption involve varied algorithms to produce the data depending on whether the encryption is symmetric or asymmetric. The process of the algorithm is used differently according to the type of encryption. This is why the person on the receiving end of the encrypted message must use the same process to access the data that was used to encrypt it.

Encryption Keys

Encryption keys have a wide variety of lengths and they also vary in strength. The possibility of number combinations is infinite, thus making it virtually impossible for even the most sophisticated hacker to guess the key combinations of the encryption.
Public asymmetric encryption schemes also use highly secure algorithms with a different method of encrypting and decrypting. This software utilizes two keys, known as a key pair. One encryption key is the public key, and can be freely shared or given to anyone because its only job is to encrypt. The other key is the private key, and is not shared. The private key is required to decrypt anything that has been encrypted by the public key.

WEB SERVERS

GenXTechno Tags: web, server, iis, pws, apache

A computer that runs a Web site. Using the HTTP protocol, the Web server delivers Web pages to browsers as well as other data files to Web-based applications. The Web server includes the hardware, operating system, Web server software, TCP/IP protocols and site content (Web pages, images and other files). If the Web server is used internally and is not exposed to the public, it is an "intranet server". Every Web server has an IP address and possibly a domain name.
Any computer can be turned into a Web server by installing server software and connecting the machine to the Internet. There are many Web server software applications, including public domain software from NCSA (National Center for Supercomputing Applications) and Apache, and commercial packages from Microsoft, Netscape and others.

Personal Web Server (PWS)

Personal Web Server is Microsoft's version of a Web server program for individual PC users who want to share Web pages and other files from their hard drive. PWS is a scaled-down version of Microsoft's more robust Web server, Internet Information Server IIS. PWS can be used with a full-time Internet connection to serve Web pages for a Web site with limited traffic. It can also be used for testing a Web site offline or from a "staging" site before putting it on a main Web site that is exposed to larger traffic.
PWS can be used together with Microsoft's FrontPage, a Web site design product, to upload Web pages from a remote location or to the local hard drive; to check for dead links; to create directories; and to set permissions. PWS is frequently used as part of the trend toward peer-to-peer exchange and publishing.
The equivalent program for the Macintosh is called Personal Web Sharing.

Internet Information Server

IIS (Internet Information Server) is a group of Internet servers (including a Web or Hypertext Transfer Protocol server and a File Transfer Protocol server) with additional capabilities for Microsoft's Windows NT and Windows 2000 Server operating systems. IIS is Microsoft's entry to compete in the Internet server market that is also addressed by Apache, Sun Microsystems, O'Reilly, and others. With IIS, Microsoft includes a set of programs for building and administering Web sites, a search engine, and support for writing Web-based applications that access databases. Microsoft points out that IIS is tightly integrated with the Windows NT and 2000 Servers in a number of ways, resulting in faster Web page serving.
A typical company that buys IIS can create pages for Web sites using Microsoft's Front Page product (with its WYSIWYG user interface). Web developers can use Microsoft's Active Server Page (ASP) technology, which means that applications - including ActiveX controls - can be imbedded in Web pages that modify the content sent back to users. Developers can also write programs that filter requests and get the correct Web pages for different users by using Microsoft's Internet Server Application Program Interface (ISAPI) interface. ASPs and ISAPI programs run more efficiently than common gateway interface (CGI) and server-side include (SSI) programs, two current technologies. (However, there are comparable interfaces on other platforms.)

Apache

Apache is generally recognized as the world's most popular Web server (HTTP server). Originally designed for Unix servers, the Apache Web server has been ported to Windows and other network operating systems (NOS). The name "Apache" derives from the word "patchy" that the Apache developers used to describe early versions of their software.

How to Setup Web Pages?

GenXTechno Tags: web, pages, page, setup, ftp

Set up your access to our FTP site - and FTP your web page to remote server.
Some important steps you have to follow for web page setup.

1. Planning your home page.
2. Getting everything you will need.
3. HTML Editors
4. FTP Clients
5. Create your home pages.
6. Uploading Web Pages.
7. Testing it out.

Planning Your Home Page

This is perhaps one of the most important steps in creating a home page because, either in your head or on paper, you are deciding what your page will look like and how you want to present it.

This can be as involved as drawing out a logical map of what connections you want, or as simple as sitting down and collecting your thoughts for what you want this page to be.

First, and foremost, consider what it is you want to put on your page. Common things to put on a page include:

• A list of links to the pages
• Information about your web site
• Information about the pages you have
• Other miscellaneous things

Getting Everything You Will Need.

The tools required to setup a home page are:

• Your Existing PPP Software
• An Editor of Your Choice (Text or HTML)
• An FTP Client

HTML Editors

You need to format your page using plain ASCII text. You create effects like bold, italics, and other effects like headings, etc, by using HTML tags. HTML stands for HyperText Markup Language.

FTP Clients

This is the software you will need to transport your web page(s) to Remote Site.

Create Your Home Page

Uploading Web Page(s)

This is the easy part and you're almost there.

1. Name your main page index.html.
2. Now you will want to switch to the FTP Client you had previously setup. You will now create a connection to client.visuallink.com with the following settings:
   
   • Hostname: 66.84.76.3 or www.xyz.com
   • Username: (Your username)
   • Password: (Your password)

Most of the recommended FTP clients work with the familiar drag-and-drop method of copying files. After bringing up your created home page on the 'local' side of the screen, you will simply 'drag' it over into your directory on the remote side.

• 
  
  Copy the files to your web directory. You must put them in your web directory on client.
• 
  
  Once your pages are uploaded to your home directory, you should (if you need to), rename the file with single extension .html.

Testing out Your Site

After successfully uploading your page, it will be located at the URL:

• http://www.xyz.com

TELNET & FTP

GenXTechno Tags: telnet, ftp, files, transfer, protocol

The Telnet protocol is often thought of as simply providing a facility for remote logins to computer via the Internet. This was its original purpose although it can be used for many other purposes. It is best understood in the context of a user with a simple terminal using the local telnet program (known as the client program) to run a login session on a remote computer where his communications needs are handled by a telnet server program. It should be emphasized that the telnet server can pass on the data it has received from the client to many other types of process including a remote login server. It is described in RFC854 and was first published in 1983.

Commands

The telnet protocol also specifies various commands that control the method and various details of the interaction between the client and server. These commands are incorporated within the data stream. The commands are distinguished by the use of various characters with the most significant bit set. Commands are always introduced by a character with the decimal code 255 known as an Interpret as command (IAC) character. The complete set of special characters is

Name	Decimal Code	Meaning
SE	240	End of subnegotiation parameters.
NOP	241	No operation
DM	242	Data mark. Indicates the position of a Synch event within the data stream. This should always be accompanied by a TCP urgent notification.
BRK	243	Break. Indicates that the "break" or "attention" key was hit.
IP	244	Suspend, interrupt or abort the process to which the NVT is connected.
AO	245	Abort output. Allows the current process to run to completion but do not send its output to the user.
AYT	246	Are you there. Send back to the NVT some visible evidence that the AYT was received.
EC	247	Erase character. The receiver should delete the last preceding undeleted character from the data stream.
EL	248	Erase line. Delete characters from the data stream back to but not including the previous CRLF.
GA	249	Go ahead. Used, under certain circumstances, to tell the other end that it can transmit.
SB	250	Subnegotiation of the indicated option follows.
WILL	251	Indicates the desire to begin performing, or confirmation that you are now performing, the indicated option.
WONT	252	Indicates the refusal to perform, or continue performing, the indicated option.
DO	253	Indicates the request that the other party perform, or confirmation that you are expecting the other party to perform, the indicated option.
DONT	254	Indicates the demand that the other party stop performing, or confirmation that you are no longer expecting the other party to perform, the indicated option.
IAC	255	Interpret as command

Associated with each of the these there are various possible responses

Sender Sent	Receiver Responds	Implication
WILL	DO	The sender would like to use a certain facility if the receiver can handle it. Option is now in effect
WILL	DONT	Receiver says it cannot support the option. Option is not in effect.
DO	WILL	The sender says it can handle traffic from the sender if the sender wishes to use a certain option. Option is now in effect.
DO	WONT	Receiver says it cannot support the option. Option is not in effect.
WONT	DONT	Option disabled. DONT is only valid response.
DONT	WONT	Option disabled. WONT is only valid response.

For example if the sender wants the other end to suppress go-ahead it would send the byte sequence 255(IAC), 251(WILL), 3The final byte of the three byte sequence identifies the required action. For some of the negotiable options values need to be communicated once support of the option has been agreed. This is done using

The Telnet Protocol
Telnet Negotiable Options Many of those listed are self-evident, but some call for more comments.

• Suppress Go Ahead

The original telnet implementation defaulted to "half duplex" operation. This means that data traffic could only go in one direction at a time and specific action is required to indicate the end of traffic in one direction and that traffic may now start in the other direction. [This similar to the use of "roger" and "over" by amateur and CB radio operators.] The specific action is the inclusion of a GA character in the data stream.Modern links normally allow bi-directional operation and the "suppress go ahead" option is enabled.

• Echo

The echo option is enabled, usually by the server, to indicate that the server will echo every character it receives. A combination of "suppress go ahead" and "echo" is called character at a time mode meaning that each character is separately transmitted and echoed. There is an understanding known as kludge line mode which means that if either "suppress go ahead" or "echo" is enabled but not both then telnet operates in line at a time mode meaning that complete lines are assembled at each end and transmitted in one "go".

• Linemode

This option replaces and supersedes the line mode kludge.

• remote flow control

This option controls where the special flow control effects of Ctrl-S/Ctrl-Q are implemented. Telnet control functions The telnet protocol includes a number of control functions. These are initiated in response to conditions detected by the client (usually certain special keys or key combinations) or server. The detected condition causes a special character to be incorporated in the data stream.

• Interrupt Process

This is used by the client to cause the suspension or termination of the server process. Typically the user types Ctrl-C on the keyboard. An IP (244) character is included in the data stream.

• Abort Output

This is used to suppress the transmission of remote process output. An AO (238) character is included in the data stream.

• Are You There

This is used to trigger a visible response from the other end to confirm the operation of the link and the remote process. An AYT (246) character is incorporated in the data stream.

• Erase character

Sent to the display to tell it to delete the immediately preceding character from the display. An EC (247) character is incorporated in the data stream.

• Erase line

Causes the deletion of the current line of input. An EL (248) character is incorporated in the data stream.

• Data Mark

Some control functions such as AO and IP require immediate action and this may cause difficulties if data is held in buffers awaiting input requests from a (possibly misbehaving) remote process. To overcome this problem a DM (242) character is sent in a TCP Urgent segment, this tells the receiver to examine the data stream for "interesting" characters such as IP, AO and AYT. This is known as the telnet synch mechanism.A DM not in a TCP Urgent segment has no effect.

The telnet command
On most Unix systems a telnet session can be initiated using the telnet command. telnet <remote host> but if the user just types telnet then various options and subcommands are available which can be used to study the behavior of the session.
Here's an exmaple of a telnet session from scitsc to ccub
bash$ telnet
telnet> toggle options
Will show option processing.
telnet> open ccub
Trying 63.14.239.165 ...
Connected to laynetworks.com.
Escape character is '^]'.
SENT do SUPPRESS GO AHEAD
SENT will TERMINAL TYPE (reply)
RCVD do TERMINAL TYPE (don't reply)
RCVD will SUPPRESS GO AHEAD (don't reply)
RCVD will ECHO (reply)
SENT do ECHO (reply)
RCVD do ECHO (reply)
SENT wont ECHO (reply)
UNIX(r) System V Release 4.0 (ccub)
RCVD dont ECHO (don't reply)
login: Login timed out after 60 seconds
Connection closed by foreign host.