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Tell about Email protocols.

  1. Tell about Asynchronous transmission.
  2. Tell about computer buses.
  3. Tell about Synchronous transmission.
  4. This book is about

There are three different email protocols that can be used to transfer and store messages: SMTP (Simple Mail Transfer Protocol), POP (Post Office Protocol) and IMAP (Internet Mail Access Protocol).

SMTP is used to transfer messages between one mail server and another. It is also used by email programs on PCs to send mail to the server. SMTP is very straightforward. Once a message has been delivered, it can't be recalled or cancelled. It's also deleted from the sending server once it's been delivered. SMTP uses 'push' operation, meaning that the connection is initiated by the sending server rather than the receiver. In host-based mail systems, such as UNIX and Web mail, SMTP is the only protocol the server uses. SMTP is the only protocol for transferring messages between servers. How they're then stored varies from system to system.

POP is a message-retrieval protocol used by many PC mail clients to get messages from a server. It only allows you to download all messages in your mailbox at once. It works in 'pull' mode, the receiving PC initiating the connection. PC-based POP3 mail clients can do this automatically at a preset interval. Since POP3 downloads all the messages in your mailbox, there's an option to leave messages on the server, so that they can be picked up from different machines without losing any. When using a Web mail account to retrieve POP3 mail, be careful about leaving messages on the server - if too many build up each download will take a long time and fill up your inbox. Many Web mail systems won't recognize messages you've already downloaded, so you'll get duplicates of ones you haven't deleted.

IMAP is similar in operation to POP, but allows you more choice over what messages you download. Initially, only message headers are retrieved, giving information about the sender and subject. You can then download just those messages you want to read. You can also delete individual messages from the server, and some IMAP4 servers let you organize your mail into folders.

3.
 
 

Describe VoiP.

Voice over Internet Protocol is a way of making calls using the Internet.

VoIP first digitizes your voice signal. The digital data is then reduces by audio compression using codecs (coder/decoder software and hardware). These operate in a similar way to MP3, which compresses music files. The compressed data is then broken into packets and sent across the Internet. At the other end, it is reconverted into audio data. Because the data rate is high, for good audio quality a broadband connection works best.

Each packet of data is delivered by any route the network can find. Packets can be delayed or lost. VoIP deals with loss by dividing the data into 30-millisecond packet. If such a small packet is lost, you won't notice.

Jitter is the term used for differences in the time packets take to arrive. VoIP uses a buffer at the receiving end to store and sequence packets. In this way, the differences are smoothed out but this can cause delays. Latency is the delay between the packets reaching the receiver and you hearing the sound. If the delay is long, it makes conversation difficult.


4. Describe steps of planning your website.

Main steps to creating a web site:

1. Analysis

2. Design and implementation

3. Evaluation

1. So you have decided that you really want a website and that this website should really be of an acceptable standard. What you need to do now is a plan:

- What is the goal of your website?

- What is the target audience of your website?

Exactly who are they and what do you know about them, what they want, what they need, what they don't know they need, what gives them the willies on the Web? Answer those questions, and any others that suit the specific customer you've now identified, and you'll know how to go forward in writing your raison d'être, your reason for being - your mission.

2. You can start designing your site. When it comes to Web design, as in so many other things, simple is better. Use only what's needed to enhance your central message and tell it quickly and clearly in an attractive setting.

You need to decide:

- Type of site - Most websites are either news/information, product, or reference sites. As such they each have a slightly different focus.

- Navigation - The navigation affects the information architecture of your site.

- Content - Content is the actual pages you'll be building.

Building a website requires that you work on one page at a time. To build your site you should be familiar with:

- Design Basics - The elements of good design and how to use it on websites.

3. Your Web site's analytics software holds the keys to staying on top of how your site is viewed and used by visitors and customers, sales, reach - essential hard data to track your online performance.

Whether you maintain your Web site alone or with help, know this:

-It seems logical that registering with a slew of search engines will make it easier for customers to find you. But one-size-fits-all may not be the most effective approach for your business type. Check your analytics to see which engines are getting the most hits, and which are doing nothing.

-Once you review this data, register with any search engines that clearly target your business audience.

-Consider adding site-tracking technology that shows what users are doing in real time. Knowing this allows you to make pinpoint-targeted special offers and information.

 



Describe buffering. | Describe how a virus infects a program.

Describe object oriented programming. | Tell about computer buses. | Tell how a disc cash works. | Tell about Asynchronous transmission. | Tell about Synchronous transmission. | Describe how browser finds the webpage. | Tell how epos till operate. | Study this diagram of a Medical centre. | Describe the MP3 process. | Describe fixed LAN. |

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