Friday, September 19, 2008

Data Communications

This module covers transmission media, both guided and unguided and provides background information on the key transmission technologies used in modern networks. We will look at wireless communication in general, as it has many other important applications besides providing connectivity to users. We will also give a brief introduction to different types of switching techniques

  • Circuit Switching
  • Packet Switching

Instructional Objectives

Upon completion of this module, you will be

1.Introduced to the following:

  • Different Transmission Media
  • Different Switching Techniques
  • Wireless Transmission

2.Able to compare between the following concepts:

  • Fiber-Optic Transmission Vs Wireless Transmission

Prerequisites

  • Basic Concepts of Data Communication
  • Devices used in a network

Module Contents

  • Transmission Techniques
    • Magnetic Media
    • Twisted Pair
    • Coaxial Cable
    • Fiber Optics
    • Wireless Transmission
  • Foundations: Switching
    • Circuits switching
    • Messages Switching
    • Packet switching

Pre-diagnostic Test

  • Pre-diagnostic Test(Data Communications):Test Yourself, before you start the module. This will help to check yourself whether you are fit to start the module or not. If the performance is not satisfactory, go through the concepts mentioned under the pre-requisites of this module.

Instruction Management

  • Information For Students:
    • Keys points are listed below:-
      • Pre-requisite: You should be comfortable with the concepts stated in the pre-requisites of this module
      • Pre-diagnostic Test: It is recommended that you should take pre-diagnostic test before you start the module. This test is to check whether you are comfortable with the concepts mentioned in the pre-requisites or not. If your performance is not satisfactory, it is better you study the key concepts and take the test once again.
      • Post-diagnostic Test: This test is to know the depth of your understanding on this module.
      • More you do more you get. So, solve the problems stated in the exercise link below.
  • Information For Teachers:

    • Key points are listed below. You are most welcome to modify it to suit you the best:-
      • The module is scheduled to cover into - lecture hours.
      • Powerpoint slides for all the lectures are provided.
      • It is advised to follow the sequence of lectures as specified
      • It is recommended to encourage the students to take the tests on time

Effective Client Communication

Whether you know it or not, your database of current and past clients is your best source of new clients. “Prospecting” for a new client is time consuming and expensive. If you can find a way to increase your sales without the time commitment and expense of cold calling, mass direct mail, advertising or purchasing leads, would you be willing to implement it? Of course, you would.

Taking the time and effort to keep in contact with past clients will grow your business through new direct sales to the client and generating referrals to qualified prospects.

Often salespeople complain that keeping in touch with past clients takes too much time, effort, and money. Considering the return on investment, this really is not true—at least for most salespeople. The key is finding a way to communicate that is time efficient, relatively inexpensive, and effective.

Studies indicate that in order to keep your name at the top of your customer’s mind, you need to “touch” your customer a minimum of 14 times per year—more if at all possible.
What is a “touch?” A touch is any communication from you to your client—email, telephone call, snail mail, postcard, holiday card, in-person meeting, or any other method of getting in front of your customer. If you are communicating with the client, you are touching them.

What is the most effective way to touch your past clients? Studies have shown that there is not a “best” way to touch the client, but rather, the most effective client communication programs enlist a number of communication formats.

Sending 14 emails, a year is better than nothing, but it is not the best way. Neither would be sending 14 snail mail pieces. Or, making 14 phone calls. Nor, sending 14 postcards during the course of the year. However, constructing a campaign using a combination of these methods could be a very effective program. For instance, setting a marketing calendar to send 4 postcards per year, 6 emails, 2 snail mail letters, one phone call, and one holiday card during the course of the year allows you to touch your client approximately once every 3 ½ weeks during the course of the year.

But, what do you send? What do you say 14 times during the course of the year? The content of your communication is just as important as the fact that you sent something. When you communicate with a past client, the fact that you have something in front of a previous customer is not necessarily a good thing, in and of itself.

Many traditional marketers will disagree. Much traditional thinking says that any time you get your name in front a client it is a good thing. However, is a 3-second trip to the trash for your expensive postcard or letter best the use of your money?
Whether or not your communication campaign is effective will depend on what you are communicating. If you send junk, just to send something, your customer will quickly learn to ignore you and your communications and everything you send will take that 3-secnd trip to the trash. On the other hand, if your communications offer something of interest and value, you will train your client to pay attention to you.

Which would you rather have: a client that ignores you, or one that pays attention to you?

I assume you would rather have a client that pays attention to you. To train your clients to pay attention, and, therefore, to keep you at the top of their mind, you must figure out how to send them communications that give them value. Can you offer a special for them or someone they refer to you? Can you provide them an annual or semi-annual update on their purchase? Can you send or email them articles of interest that relate to their purchase or an interest of theirs? What you send does not have to be large or costly—it just needs to be of interest to the client.

A program such as this requires thought and considerable customization of content, but the payoff can be enormous. Think about what you are sending and what it will—or will not—communicate about you and your business. If you want your clients to think of you and not ignore you, then take the time and the effort to make sure you are sending value. If you are not sure it has value, it probably does not. Marketing to your client database should be at the top of your “to do” list and your campaign should be constructed with the thought and care as if you were marketing to the most important people in the world, because for you, they are.

Nonverbal Communication Study

Nonverbal communication is a silent infiltrator, having broad influence over our social environment. It provides us with a mode for conveying messages without the use of verbal language. It may enhance or detract from a verbal communication. It regulates relationships by affecting the likelihood of introduction and continued interaction. We are able to infer emotion through nonverbal communication and influence other's perception of our competence, power and vulnerability. It also plays a role in the perception of the actual message we are trying to convey. It affects our lives in a myriad of ways from childhood throughout adulthood, and as long as we intend to communicate with others.

What is it about the internet that is so appealing? In the past year, people have flocked to the internet. According to estimates from 1994, 25 million people are communicating on the internet worldwide. Most people who have access to e-mail will tell you that they keep in touch with people better than they ever did before; but they can't remember the last time they actually "mailed" a conventional letter. Internet users even refer to the U.S. Postal service as "snail mail."

No doubt, part of the appeal, particularly e-mail and chat capabilities, comes from the "instant" gratification that comes with the internet. An e-mail can be sent around the world in a matter of seconds. Even better, real-time chat allows users living on different continents to communicate as if by phone, without face to face interaction. Computer-mediated communication (CMC) offers new paradigms for thought and communication and opens up new possibilities for human interaction.

Even internet "romance" is alive and well. People are now marrying their internet "loves." Other people just stick to the cybersex. Just about anything you can find "In Real Life" you can find represented on the internet. Important visible cues, however, are missing from the net. These nonverbal cues play a role in real life face to face communication, but are not represented equally on the internet. How does the lack of nonverbal cues affect communication on the internet?

Nonverbal communication is defined as the process by which nonverbal behaviors are used, either singly or in combination with verbal behaviors, in the exchange and interpretation of messages within a given situation or context. If communication is considered a type of matrix, there are distinctions between verbal and nonverbal behaviors that can be divided into vocal and nonvocal behaviors. The result is a matrix consisting of four potential sets of communication behaviors: verbal/vocal behaviors, verbal/nonvocal behaviors, nonverbal/vocal behaviors, and nonverbal/nonvocal behaviors.

Nonverbal communication is thought to comprise six functions in human communication. These functions consist of complementing verbal messages, substituting for verbal messages, accenting verbal messages, contradicting verbal messages, repeating verbal messages, and regulating verbal messages. Each of these functions of nonverbal communication are, for the most part, missing during the course of using the internet as a communication tool.

The complementing function of nonverbal communication includes nonverbal cues -- such as tone of voice, facial expression, gestures, or distance between people -- often serving to complement the verbal message and add to, clarify, or reinforce the meaning. The term "complement" indicates that the behavior alone would not communicate the intended message. "A complementing nonverbal message changes the meaning of the verbal message by adding additional insights or information". This function of nonverbal cues on the internet is missing in any message sent by e-mail or chat. If a person writes "I hate college" on the internet, we can't make an assumption on the truth of the statement without more information. They could be laughing when they say it, or frowning, or crying -- all of those nonverbal cues would make a difference in determining the meaning behind the words. Some internet users try to duplicate these nonverbal cues with "netiquette" -- by using smiley faces or words describing their feelings in parentheses. The message sender can reflect some of the missing nonverbal cues by sending the cues as written words.

It's kind of like the terrible two's. Where children are discovering what they can do with their own kinesthetics. This is a time where children like to touch everything they see. It doesn't matter what it is. If they see it, they want to have the experience of touching it. Often times you can find them totally lost in the moment, fully absorbed in whatever kinesthetic experience they are indulging in at that moment. It's like a moment frozen in time. As they sit there manipulating that object, time passes, but for them there is no awareness of time, only the moment.

When I was younger I often found myself being fascinated with how well some the animals who traveled with the circus's were able to understand their trainers. Also, I had a friend who trained attack dogs. He would often train the one that he considered the brightest, and that dog would help in training the others. What I found in common with my friend who trained the dogs, and animal trainers who worked with the animals in the circus, was their ability to use non-verbally coded methods of communication.

Communication is a complex dynamic system. It involves all modes of sending receiving and feedback. It appears at a young age and decoding ability increases with age. At times nonverbal cues may be used to emphasize a message we are trying to convey. On other occasions it replaces verbal communication. Communication is used in everyday life, from greeting a stranger to touching a lover. The nonverbal behavior an individual uses is a product of characteristics endowed at birth and socially learned norms.

Knowledge of the effects nonverbal communications introduce is needed, because our awareness may enhance favorable communication. Nonverbal cues may be unconsciously acted and reacted upon, regulating proximity, gestures, eye gaze and touch. Each component of nonverbal behavior affects our relationship and interpersonal environment in intricate ways. Nonverbal cues provide insight into affect states, influence another's perception of an individual's competence, persuasiveness, power, sincerity and vulnerability. In a new age where increasing population is decreasing personal space, it is imperative to understand cultural and personal communication differences and similarities.

Avoiding Data Loss

We all know the effects of data loss –but exactly what is it?

Data loss - A crash in computing is a condition where a program (either an application or part of the operating system) stops performing its expected function and also stops responding to other parts of the system. Often the offending program may simply appear to freeze. If this program is a critical part of the operating system kernel the entire computer may crash (a system crash).

Having noted the definitions for data loss I’ll note a few reasons why it occurs, and how to recover the data, as well as a few links to specialized sites.

1. User error - A simple mistake on behalf of an employee could lead to the loss of megabytes of critical company data. From the deletion of a critical file to the accidental deletion of database records, your customers could face large expenses and significant down time recovering the disaster created by a simple mistake.

2. Employee theft - Employees need access to sensitive data in order to perform their jobs. Your customers have to limit the information to which employees have access, ensure that terminated employees no longer have access to sensitive data, and be able to track who's touching what, when and how.

3. Disaster - What natural disasters or unfortunate accidents might affect business? Magazines daily contain news of organizations that have faced unbelievable catastrophes. In the event that your or your customers' organizations are hit with a fire, flood or other disaster, how will the data be protected?

One way is to have backups. Using an Iomega REV drive powered by Iomega Automatic Backup Pro software, configure a full backup to REV 35GB disks once a week. Once this backup is done, you can secure the full backup offsite. With your data now backed up in two locations, no single event will be able to damage both sets of data. This backup can be done through backing software, like Argentum™ Backup , which automatically detects and locates the proper paths, folders and files under any Microsoft Windows (95, 98, ME, NT, 2000, XP and 2003) platform. Argentum Backup does it for sure, without any mistake or occasion. Argentum Backup is designed to be suitable for both beginners and advanced users

But, the best and newest way are the online backup solutions, which help you protect your data on a regular basis (daily, weekly or monthly). One of this sites is Iomega iStorage, from one of the best backup companies. This site offers a feature-rich, highly secure online storage vault designed perfectly to meet the needs of small and medium-sized businesses. Includes administrative abilities that give you control of content shared and accessed. It creates multiple logins to the same account, giving members their own login and storage space and creates logins for guests to use with restricted access

Another site is www.backup.com, where you can find another on-line backup system, called @backup. It’s main features are:

·simple finding and selecting of files is made easy with our right mouse click options or with our explorer-like interface;

·You don’t have to remember to do a backup. @Backup remembers for you. You set your backup schedule and we do the rest;

·They encrypt your data with bank level security procedures before transferring over the Internet to our data centers. Your data is stored encrypted and only accessible with your password.

·You can restore files anytime. In the event of a crash, a virus infection, or a simple user error your backups are a click away. Additionally you have access to your files from any PC anywhere.

These are just two of the sites that offer you on-line backup system. The internet is packed with offers that vary from the size of the backup they provide to the monthly cost of the service. For your help, I’ve included a few links, to other sites, where you can find details and prices for on-line backups.

Thursday, September 18, 2008

Broadband Work

These days, "broadband" is a word that is thrown around easily in telecommunications and internet lingo, but the average consumer may not have a clear understanding of how broadband works. It's easy to understand why; the technology industry even has trouble defining it clearly. So how does broadband work? The online Webster's dictionary defines broadband as "A class of communication channel capable of supporting a wide range of frequencies, typically from audio up to video frequencies. A broadband channel can carry multiple signals by dividing the total capacity into multiple, independent bandwidth channels, where each channel operates only on a specific range of frequencies." Let's take a look at each part of the definition to understand how broadband works.

The first part of answering the question 'how does broadband work' is to think about the phrase a "class of communication channel." We can gather from this that it is different from the normal class of communication channel that we use - our regular phone lines. Phone lines, also called baseband lines, normally carry 29.6kbps of analog data when used for voice communications. But with the advent of the internet, people began to demand faster data transmission. A regular, baseband phone line can carry up to 56kbps of data with the help of a high-speed modem, but without additional technology, that is its maximum capacity.

That wasn't nearly fast enough to keep up with the average person's demand for and dependency on the internet, which led to the demand for broadband. So how does broadband work? If you think of a baseband line as having one "channel" to send information, you can think of a broadband line as having multiple channels that you use at the same time. Not only that, but a broadband connection is capable of carrying a wider range and type of frequencies, meaning different types of data. And what it can carry, it carries faster. When you drive on the interstate, what happens when there aren't enough lanes for the number of cars on the road? Everyone is forced to go slower.

The same happens with the internet. Think of your connection to the internet as a tunnel that links your computer to the internet. A regular phone line can allow only a small amount of data to pass through at a time. In comparison, a broadband is a wider (or broader) tunnel, allowing a greater amount of information to pass through your connection at one time. The breadth of this tunnel is called "bandwidth." The more bandwidth you have, the faster you can move data. With broadband service, you can also download files that require a great deal of different types of frequencies as well, such as audio and video files.

This is a partial answer to the question 'how does broadband work,' but the other has to do with the way that broadband services can compress and transmit that data that you're sending. Go back to the cars on the interstate analogy. What if suddenly all of the cars could be miniaturized? What would that do to the traffic jam? Or if they could use all of the space available in the tunnel - above your head, between cars, etc. Broadband technology not only widens the channels you have, but it uses them more efficiently. Meaning you can get more out of the bandwidth that you have. Broadband makes your internet experience faster and more efficient overall.

Cisco Certification: Cabling Cisco Devices

Unshielded Twisted Pair (UTP) is a cable that has four pairs of wires twisted inside it to eliminate electrical interference. UTP cables are connected using RJ-45 connectors that have eight connector pins. The data equipment that is used for internetworking is classified as Data Terminal Equipment (DTE e.g. router interfaces) and Data Communication Equipment (DCE e.g. A WAN connects DTEs through DCE network).

UTP cables are used in many configurations and for different purposes, to form an internetwork including:

Straight-through

Crossover

Rollover

Applications of UTP include:

Serial transmission

Integrated Service Digital Network (ISDN) connections

Console connections

Modular and fixed interfaces

These configurations and applications are discussed below.

Straight-Through Cable

A straight-through cable is the standard network cable connection and is used to connect the source and destination computers through an internetworking device. Specifically, you can use it to connect a host to a hub or switch

Crossover Cable

In a crossover cable, the standard RJ-45 cable between the source and destination computers is cross-connected. A crossover cable can be used to connect:

Two computers

Two hubs

A hub to a switch

A cable modem to a router

Two router interfaces

Rollover Cable

These Cisco proprietary cables used to connect to a router or switch console port. In a rollover cable (8 pins), RJ-45 connectors are usually present at each ends and are used to connect router and computer ports. Pin 1 on one end of cable connects to Pin 8 at the other end of the cable, similarly, Pin 2 connects Pin 7, and so on.

Serial Transmission

All WANs use serial transmission, which can pass one bit at a time over a single channel. Cisco provides a 60-pin serial connector for one end of the cable while other end of the cable may be EIA/TIA-232, V.35, EIA/TIA-449, X.21 or others;

ISDN Connections

ISDN refers to a collection of standards that define a digital architecture that can carry integrated voice and data, using the public-switched network. ISDN BRI (Basic Rate Interface) is a two 64 kbps Bearer channels (2B) plus one 16 kbps Data channel (D) service. ISDN BRI terminates at the customer premise with the U interface.

Console Connections

A console is a type of DTE through which commands are entered into the host device. Most Cisco devices support the RJ-45 console connection. A rollover cable with an RJ-45 connector is used to connect the PC or terminal to the console port of the Cisco device.

Modular and Fixed Interfaces

Unlike a fixed interface router, a modular interface router allows you to add new interface cards without buying a new router.

In the fixed interface series, you refer to the interfaces as:

interface_type interface_number

For example, the first serial interface on a Cisco 2503 router would be referred to as serial 0. Higher routers have modular interfaces that allow you to change the interfaces as and when required. Here, the interfaces are referred to as:

interface_type module_number/interface_number

To practice such commands you can download a free CCNA router simulator from and proceed to the troubleshooting 1 exercise that configures ethernet 0 interface.

Time to Redefine Telecom

Telecommunication, according to Wikipedia, is the extension of communication over a distance. In practice, it also recognizes that something may be lost in the process; hence the term 'telecommunication' covers all forms of distance and/or conversion of the original communications, including radio, telegraphy, television, telephony, data communication and computer networking.

While defining telecom gets more and more difficult, the profit and ethics behind the business keep on diminishing. SBC spent $16B to a company whose revenue stream is declining more than 10% year over year. Verizon bought MCI, and in order to make deal lucrative, they say they will layoff over 7,000 people.

The reason for scaling-down in telecom is that the technological advancement has terribly been focused on communications. We all owe a thank to nineties for that... Lots of technical people has seen the future in Telecom and made huge amounts of mind investment to the business. Today, we are forced to live in an overly competitive industry where telecom is forced to be cheaper everyday. To make matters worse, a company called Skype appeared. This global P2P Telephony Company decided to make old fashioned definition of telecom a commodity through its software, which allows you to make free calls over the Internet. Other emerging companies like Net2Phone and 8x8 also flocked customers to make cheaper (sometimes free) calls.

Some traditional telecom companies have kept an awry eye on those start-ups while adopting technologies like VoIP. They mostly thought those new technologies are something to monitor and investigate. In other words, they are disruptive. Some assumed the danger and started firing QoS bullet, as those startups do not provide top-notch service like incumbents do.

The fact of the matter is, none of those business plans will hold true should they are based on making money on calls. Like Michael Powell said, “I knew it was over when I downloaded Skype...”

So, can we say that telecom is a commodity?

My answer would be no, if network providers accept to change their musty mindset. Three things are important if the full background of this new notion is to be understood. First is, telecoms exist to provide infrastructure. The rest needs to be handled by networking and computing companies.

The need for voice, video and data are going hand in hand. There is no value in them when there is no Internet. That’s why, the second is, the new business plan should be based on the Internet access. If telecoms want to survive, charging customers packet-based with the guarantee of excellent QoS is the only way to go. MPLS is their material to make this happen.

This way, optimization, the biggest concern of telecom industry, can be solved as the packet usage can be approximated. Demoting VoIP into an application to where it originally is can be doable in packet-based model. This new model will also disallow fighting against free-of-charge models and bring a fresh breath to network providers to generate more revenue.

Third is, not only the ability of optimization but also the prioritization and security of the traffic, if needed, will let network providers to put extra cash to their pockets. The money behind the content will not be their ball game.

Some may argue that there is no incremental cost of extra usage of packets to a network so the value behind tracking the traffic is nonsense. However, what is unseen is that it forces network providers to upgrade their systems quicker. They can also build their cost /profit structure easier.

Perils to the model would be the evolution span of MPLS and anti-spam systems. MPLS, as an immature technology, is welcomed with high expectations. Addressing all needs in such a short period of time needs a lot of investment. The story is almost the same for anti-spam solutions too. No customer would like to pay extra for spam as this is adding to the traffic that a user is using. That would force network providers to unify on an MPLS/ anti-spam model where they and their customers can rely on.

Once this new role of incumbents is well assumed with solid technology, then converting the so-called threat of telecom commoditization into an opportunity is feasible.