Question

Short Answers - Subject - Telecommunication System & Management.

1. How can data communications networks affect businesses?

2.     From your own knowledge or background, discuss and describe three important applications of data communications networks for strategic, competitive advantage in business use. Give examples of three real world firms who have used networks for competitive advantage in the marketplace and discuss why these networks contributed to their expertise or competitive advantage.

3.     How do LANs differ from WANs, and BNs?

4.     Draw a diagram of the Internet model and describe what each of the five layers do. Put three examples of standards on each of your layers in the diagram. Do this in detail, explaining how a message is transmitted from one computer to another using this model.

5.     How are Internet standards developed? What is a de facto standard?

6.     Describe two important data communications standards-making bodies. How do they differ?

7.     What is the purpose of a data and network communication standard? Give five examples of various standards and describe what that standard is (e.g., RS 232, HTTP, etc.)

8. Discuss three trends in communications and networking. Be sure to give four points for each of these trends, plus two in depth examples in your response.

9. Compare and contrast a backbone network (BN), a LAN, and a WAN. Do most organizations build WANs?

10. What are the three basic hardware components for a data communication network? Describe the functions of these.

11. Why are standards important?

12. Describe the address naming structure of computers on the Internet.

13. What is the difference between an extranet and intranet?

14. What are the seven layers of the OSI model and what does each of these layers do? How does the OSI model compare to the Internet model? What does OSI stand for, and who developed this model?

15. What is VOIP? What are some examples of companies that provide VOIP as a service to their customers?

16. Explain why it is such a great time to be an IT professional.

Answer 1

1. Data communication networks can affect business by being the foundations or some organization for distributed systems(autonomous computers) in which the information system applications are divided among a network of computers

they also provide message transfer the services to allow the users of computers to talk over the internet or any Emails...

2. There are two major aspects of business data communications: The network, which includes networking technology and communications services, and; the business data communications applications that run on the network. ... Workstations such as desktop computers or laptop computers used in business operations.

Eg: radio broadcasting system, computer networks, Internet...!

3.A LAN (local area network) is a group of computers and network devices connected together, usually within the same building. ... A WAN connects several LAN s, and may be limited to an enterprise (a corporation or an organization) or accessible to the public.....!!

4.

Application Layer:

The Application layer generates a message. In this case, the specific application is a web browser requesting a webpage download. This message is then sent to the Transport layer.

Transport Layer:

The Transport layer adds the TCP or UDP header which includes the source and destination port addresses. Additional information like the packet sequence number used for TCP will also be added to the header. The data generated by the transport layer is referred to as a Segment if TCP is used, and is referred to as a Datagram if UDP is used. This segment is then sent to the Network layer.

Network Layer:

The Network layer adds a header including the source and destination IP address to generate a packet. This packet is then sent to the Data Link layer.

Data Link Layer:

The Data Link layer adds a header containing the MAC address information to create a frame. The frame is then sent it to the Physical layer to transmit the bits..

5. De Facto Standard Definition. A de facto standard is a standard that has become a standard because it is widely used rather than because it was officially approved by some standards organization or government. ... There is a strong incentive for businesses to create and control standards

6. The use of standards makes it much easier to develop software and hardware that link different networks because software and hardware can be developed one layer at a time. The software or hardware defined by the standard at one network layer can be easily updated, as long as the interface between that layer and the ones around it remains unchanged.

7. There are two types of standards: formal and de facto. A formal standard is developed by an official industry or government body. For example, there are formal standards for applications such as Web browsers (e.g., HTTP, HTML), for network layer software (e.g., IP), data link layer software (e.g., Ethernet IEEE 802.3), and for physical hardware (e.g., V.90 modems). Formal standards typically take several years to develop, during which time technology changes, making them less useful.

De facto standards are those that emerge in the marketplace and are supported by several vendors but have no official standing. For example, Microsoft Windows is a product of one company and has not been formally recognized by any standards organization, yet it is a de facto standard. In the communications industry, de facto standards often become formal standards once they have been widely accepted.

International Organization for Standardization One of the most important standards-making bodies is the International Organization for Standardization (ISO),2 which makes technical recommendations about data communication interfaces (seewww.iso.org). ISO is based in Geneva, Switzerland. The membership is composed of the national standards organizations of each ISO member country.

American National Standards Institute The American National Standards Institute (ANSI) is the coordinating organization for the U.S. national system of standards for both technology and nontechnology (see www.ansi.org). ANSI has about 1,000 members from both public and private organizations in the United States. ANSI is a standardization organization, not a standards-making body, in that it accepts standards developed by other organizations and publishes them as American standards. Its role is to coordinate the development of voluntary national standards and to interact with ISO to develop national standards that comply with ISO’s international recommendations. ANSI is a voting participant in the ISO.

10.

• Network Interface Card (NIC)

• Hub

• Switches

• Cables and connectors

• Router

• Modem

1. Network Interface Card

Network adapter is a device that enables a computer to talk with other computer/network. Using unique hardware addresses (MAC address) encoded on the card chip, the data-link protocol employs these addresses to discover other systems on the network so that it can transfer data to the right destination.

There are two types of network cards: wired and wireless. The wired NIC uses cables and connectors as a medium to transfer data, whereas in the wireless card, the connection is made using antenna that employs radio wave technology. All modern laptop computers incorporated wireless NIC in addition to the wired adapter.

Network Card Speed

Network Interface card, one of the main computer network components, comes with different speeds, 10Mbps, 100Mbps, and 1000Mbps, so on. Recent standard network cards built with Gigabit (1000Mbps) connection speed. It also supports to connect slower speeds such as 10Mbps and 100Mbps. However, the speed of the card depends on your LAN speed.

For example, if you have a switch that supports up to 100Mbps, your NIC will also transfer a data with this same speed even though your computer NIC has still the capability to transfer data at 1000Mbps (1Gbps). In modern computers, network adapter is integrated with a computer motherboard. However if you want advanced and fast Ethernet card, you may buy and install on your computer using the PCI slot found on the motherboard (desktop) and ExpressCard slots on laptop .

2. Hub

Hub is a device that splits a network connection into multiple computers. It is like a distribution center. When a computer request information from a network or a specific computer, it sends the request to the hub through a cable. The hub will receive the request and transmit it to the entire network. Each computer in the network should then figure out whether the broadcast data is for them or not.

Currently Hubs are becoming obsolete and replaced by more advanced communication devices such as Switchs and Routers.

3. Switch

Switch is a telecommunication device grouped as one of computer network components. Switch is like a Hub but built in with advanced features. It uses physical device addresses in each incoming messages so that it can deliver the message to the right destination or port.

Like Hub, switch don’t broadcast the received message to entire network, rather before sending it checks to which system or port should the message be sent. In other words switch connects the source and destination directly which increases the speed of the network. Both switch and hub have common features: Multiple RJ-45 ports, power supply and connection lights.

4. Cables and connectors

Cable is one way of transmission media which can transmit communication signals. The wired network typology uses special type of cable to connect computers on a network.

There are a number of solid transmission Media types, which are listed below. - Twisted pair wire

It is classified as Category 1, 2, 3, 4, 5, 5E, 6 and 7. Category 5E, 6 and 7 are high-speed cables that can transmit 1Gbps or more. -

Coaxial cable

Coaxial cable more resembles like TV installation cable. It is more expensive than twisted-pair cable but provide high data transmission speed.

Fiber-optic cable

It is a high-speed cable which transmits data using light beams through a glass bound fibers. Fiber-optic cable is high data transmission cable comparing to the other cable types. But the cost of fiber optics is very expensive which can only be purchased and installed on governmental level.

5. Router

When we talk about computer network components, the other device that used to connect a LAN with an internet connection is called Router. When you have two distinct networks (LANs) or want to share a single internet connection to multiple computers, we use a Router.

In most cases, recent routers also include a switch which in other words can be used as a switch. You don’t need to buy both switch and router, particularly if you are installing small business and home networks.

There are two types of Router: wired and wireless. The choice depends on your physical office/home setting, speed and cost.

11. The Importance of Standards. Standards provide people and organizations with a basis for mutual understanding, and are used as tools to facilitate communication, measurement, commerce and manufacturing. Standards are everywhere and play an important role in the economy, by: facilitating business interaction.

12. More precisely: A name is a symbol, such as human-readable text string, which identifies a resource such as a process, device, or service. An address is a data structure, understood by the network, used to specify the destination of a connection/message/packet. ... The neighboring nodes in a network are connected by links.

13. The major difference between the two, however, is that an intranet is typically used internally. While an extranet allows businesses to communicate with clients and vendors, an intranet allows employees and colleagues to work with each other in a virtual space — no outside parties are involved.

14. The International Standards Organization (ISO) developed the Open Systems Interconnection (OSI) model. It divides network communication into seven layers. Layers 1-4 are considered the lower layers, and mostly concern themselves with moving data around. ..

1. Physical Layer (Layer 1) :

The lowest layer of the OSI reference model is the physical layer. It is responsible for the actual physical connection between the devices. The physical layer contains information in the form of bits. It is responsible for the actual physical connection between the devices. When receiving data, this layer will get the signal received and convert it into 0s and 1s and send them to the Data Link layer, which will put the frame back together.

The functions of the physical layer are :

1. Bit synchronization: The physical layer provides the synchronization of the bits by providing a clock. This clock controls both sender and receiver thus providing synchronization at bit level.
2. Bit rate control: The Physical layer also defines the transmission rate i.e. the number of bits sent per second.
3. Physical topologies: Physical layer specifies the way in which the different, devices/nodes are arranged in a network i.e. bus, star or mesh topolgy.
4. Transmission mode: Physical layer also defines the way in which the data flows between the two connected devices. The various transmission modes possible are: Simplex, half-duplex and full-duplex.

* Hub, Repeater, Modem, Cables are Physical Layer devices.
** Network Layer, Data Link Layer and Physical Layer are also known as Lower Layers or Hardware Layers.

2. Data Link Layer (DLL) (Layer 2) :

The data link layer is responsible for the node to node delivery of the message. The main function of this layer is to make sure data transfer is error free from one node to another, over the physical layer. When a packet arrives in a network, it is the responsibility of DLL to transmit it to the Host using its MAC address.
Data Link Layer is divided into two sub layers :

1. Logical Link Control (LLC)
2. Media Access Control (MAC)

The packet received from Network layer is further divided into frames depending on the frame size of NIC(Network Interface Card). DLL also encapsulates Sender and Receiver’s MAC address in the header.

The Receiver’s MAC address is obtained by placing an ARP(Address Resolution Protocol) request onto the wire asking “Who has that IP address?” and the destination host will reply with its MAC address.

The functions of the data Link layer are :

1. Framing: Framing is a function of the data link layer. It provides a way for a sender to transmit a set of bits that are meaningful to the receiver. This can be accomplished by attaching special bit patterns to the beginning and end of the frame.
2. Physical addressing: After creating frames, Data link layer adds physical addresses (MAC address) of sender and/or receiver in the header of each frame.
3. Error control: Data link layer provides the mechanism of error control in which it detects and retransmits damaged or lost frames.
4. Flow Control: The data rate must be constant on both sides else the data may get corrupted thus , flow control coordinates that amount of data that can be sent before receiving acknowledgement.
5. Access control: When a single communication channel is shared by multiple devices, MAC sub-layer of data link layer helps to determine which device has control over the channel at a given time.

* Packet in Data Link layer is referred as Frame.
** Data Link layer is handled by the NIC (Network Interface Card) and device drivers of host machines.
*** Switch & Bridge are Data Link Layer devices.

3. Network Layer (Layer 3) :

Network layer works for the transmission of data from one host to the other located in different networks. It also takes care of packet routing i.e. selection of the shortest path to transmit the packet, from the number of routes available. The sender & receiver’s IP address are placed in the header by network layer.
The functions of the Network layer are :

1. Routing: The network layer protocols determine which route is suitable from source to destination. This function of network layer is known as routing.
2. Logical Addressing: In order to identify each device on internetwork uniquely, network layer defines an addressing scheme. The sender & receiver’s IP address are placed in the header by network layer. Such an address distinguishes each device uniquely and universally.

* Segment in Network layer is referred as Packet.

** Network layer is implemented by networking devices such as routers.

4. Transport Layer (Layer 4) :

Transport layer provides services to application layer and takes services from network layer. The data in the transport layer is referred to as Segments. It is responsible for the End to End delivery of the complete message. Transport layer also provides the acknowledgment of the successful data transmission and re-transmits the data if an error is found.
• At sender’s side:
Transport layer receives the formatted data from the upper layers, performs Segmentation and also implements Flow & Error control to ensure proper data transmission. It also adds Source and Destination port number in its header and forwards the segmented data to the Network Layer.
Note: The sender need to know the port number associated with the receiver’s application.
Generally, this destination port number is configured, either by default or manually. For example, when a web application makes a request to a web server, it typically uses port number 80, because this is the default port assigned to web applications. Many applications have default port assigned.
• At receiver’s side:
Transport Layer reads the port number from its header and forwards the Data which it has received to the respective application. It also performs sequencing and reassembling of the segmented data.

The functions of the transport layer are :

1. Segmentation and Reassembly: This layer accepts the message from the (session) layer , breaks the message into smaller units . Each of the segment produced has a header associated with it. The transport layer at the destination station reassembles the message.
2. Service Point Addressing: In order to deliver the message to correct process, transport layer header includes a type of address called service point address or port address. Thus by specifying this address, transport layer makes sure that the message is delivered to the correct process.

The services provided by transport layer :

1. Connection Oriented Service: It is a three-phase process which include
   – Connection Establishment
   – Data Transfer
   – Termination / disconnection
   In this type of transmission, the receiving device sends an acknowledgment, back to the source after a packet or group of packet is received. This type of transmission is reliable and secure.
2. Connection less service: It is a one phase process and includes Data Transfer. In this type of transmission, the receiver does not acknowledge receipt of a packet. This approach allows for much faster communication between devices. Connection oriented Service is more reliable than connection less Service.

* Data in the Transport Layer is called as Segments.
** Transport layer is operated by the Operating System. It is a part of the OS and communicates with the Application Layer by making system calls.
Transport Layer is called as Heart of OSI model.

5. Session Layer (Layer 5) :

This layer is responsible for establishment of connection, maintenance of sessions, authentication and also ensures security.
The functions of the session layer are :

1. Session establishment, maintenance and termination: The layer allows the two processes to establish, use and terminate a connection.
2. Synchronization : This layer allows a process to add checkpoints which are considered as synchronization points into the data. These synchronization point help to identify the error so that the data is re-synchronized properly, and ends of the messages are not cut prematurely and data loss is avoided.
3. Dialog Controller : The session layer allows two systems to start communication with each other in half-duplex or full-duplex.

**All the below 3 layers(including Session Layer) are integrated as a single layer in TCP/IP model as “Application Layer”.
**Implementation of these 3 layers is done by the network application itself. These are also known as Upper Layers or Software Layers.

SCENARIO:
Let’s consider a scenario where a user wants to send a message through some Messenger application running in his browser. The “Messenger” here acts as the application layer which provides the user with an interface to create the data. This message or so-called Data is compressed, encrypted (if any secure data) and converted into bits (0’s and 1’s) so that it can be transmitted.

6. Presentation Layer (Layer 6) :

Presentation layer is also called the Translation layer.The data from the application layer is extracted here and manipulated as per the required format to transmit over the network.
The functions of the presentation layer are :

1. Translation : For example, ASCII to EBCDIC.
2. Encryption/ Decryption : Data encryption translates the data into another form or code. The encrypted data is known as the cipher text and the decrypted data is known as plain text. A key value is used for encrypting as well as decrypting data.
3. Compression: Reduces the number of bits that need to be transmitted on the network.

7. Application Layer (Layer 7) :

At the very top of the OSI Reference Model stack of layers, we find Application layer which is implemented by the network applications. These applications produce the data, which has to be transferred over the network. This layer also serves as a window for the application services to access the network and for displaying the received information to the user.
Ex: Application – Browsers, Skype Messenger etc.
**Application Layer is also called as Desktop Layer.

The functions of the Application layer are :

1. Network Virtual Terminal
2. FTAM-File transfer access and management
3. Mail Services
4. Directory Services

OSI model acts as a reference model and is not implemented in Internet because of its late invention. Current model being used is the TCP/IP model.

15.

Top 5 Business VoIP Solutions

• Nextiva. Visit.
• Vonage Business. Visit.
• RingCentral. Visit.
• Jive Communications. Visit.
• Dialpad. Visit..

16.

Information technology is a progressive and constantly changing industry, promising a wide range of opportunities. If you have always loved the idea of working with computers,a career in information technology is the ideal pathway for you to choose.

Whether you are interested in technical support, network administration, or software development, our TAFE courses can help you define your strengths and lead you on the right path to success. To make your decisions easier, we’ve listed seven great reasons to work in information technology.

Click here to see full list of Information Technology courses

1. Opportunities

Information technology is a rapidly evolving field. No matter what industry you’re looking into, most modern businesses need people with general skills and knowledge of how to support information technology activities in the workplace.

With a Certificate III in Information, Digital Media and Technology (ICT30115), you can find work in the areas of technical support, network administration, web technologies software applications, and digital media and technologies. You could be employed in roles such as:

• Helpdesk officer
• Helpdesk assistant
• ICT operations support
• ICT user support
• PC support

2. Variety

One of the most exciting aspects of having a career in information technology is how it overlaps with so many industries. This means you can find work in just about any sector you like - the possibilities are endless.

You might find yourself pursuing a path in medicine, healthcare, transportation, arts and entertainment, financial services, education, law, agriculture, or not-for-profits. Get started by looking into a range of IT and computing courses or TAFE courses. Think about the industries you’re interested in, and start applying for work.

3. Growth

As technology continues to evolve, your career can too. Information technology isn’t a static industry. New opportunities open up every day within companies or in related fields. With TAFE courses like the Certificate III in Information, Digital Media and Technology under your belt, you can rise up.

Graduates can also choose to undertake further study through different IT and computing courses to expand your knowledge and skills. While technical support might be the right career for you in information technology, further study can open up more roles within the industry, such as:

• Software Engineer
• Systems Analyst
• Technical consultant
• Information technology coordinator
• Designing and programming computer games.

• 4. Challenges

  When you become a technology professional, your key goal is to solve every problem that people run into. If you’re ready to face these challenges, the information technology industry will bring out the best in you. Whether you work in technical support, network administration or as a software engineer, you work will rarely be boring.
  
  So much of the IT process relies on creativity and problem-solving. Our TAFE courses will give you the skills needed to respond to technical problems with innovative solutions, and make positive impacts on the success of workplaces.

  5. Money

  As technology underpins the success of many different industries, it’s no surprise that technology professionals are in high demand. As long as digital problems exist within a workplace, talented technology professionals will always be employed.
  
  Depending on the industry, this demand can translate into considerable earning potential. The more difficult the work, the more it’s valued. With most IT work requiring a specific set of skills and experience, technology professionals are often among the most well-paid employees in a business or organisation.

  6. Satisfaction

• this is main in any job....

  Essentially, working in IT means you get to help people in one way or another. For example, if you’re working in a support role, you assist people in fixing their problems or giving advice on how to improve their work. On the other hand, if you’re a developer, you can create solutions for all types of need