Examining The Types Of Communication Networks Information Technology Essay

Nowadays there are many ways in which people communicate, because communication became an essential in our daily life. Communication can be done orally and none verbally such type of communication can be done through writing in letters or emails. When the communication is done through the internet then it will be called a Communication Network. Communication are set so that messages can be passed from one part of the network to another though various nodes and multiple links.

Communication networks is a made up from five basic components that are all present in each network environment. Those components are: terminals, telecommunications processors, telecommunications channels, computers, and telecommunications control software.

Function of each component:

Terminals: Devices used to transmit or receive data.

Processors: used to support data transmission and data reception.

Communication channels: are the ways and methods in which the date is transmitted.

Computers: are the devices connected to the network in order to provide data and communication.

Control Software: is responsible about controlling all the network activities.

When we talk about communication network it’s much more than the basic communication done through the internet. We have two main types of communication networks in which we can communicate through. These two basic types on communication network are WAN AND LAN, when WAN stands for Wide Area Network, and LAN stands for Local Area Network. From there we can interpret that there is a great difference between both networks.

The Wide Area Network is a network that covers a large geographical area, like connecting one city to the other WAN is more like a group of interconnected LAN networks,and it may be limited to an enterprise such as a corporation or an organization, also it can be accessible to the public. WANs provided by service provider connection a collection of LANs to the internet, for that the Internet is considered to be an example of a worldwide public WAN. WANs are widely used by big businesses, whether statewide or multinational, it’s also used by governmental, educational, research or philanthropic enterprises.

The Local Area Network is a smaller type of networks, usually limited with an office base. The most common type of Local Area Networks is the Ethernet. Connection is established between the workstations physically components these physical technologies that build a LAN can be described generally as follows:

A physical media such as a cable is used to connect the devices,

Interfaces (such as an interface network card) on the individual devices that are connected to the media.

Protocols are used transmit data across the network.

Application Software that negotiates, interprets, and administers the network and its services.

Local Area Network especially if they were large or connected to other networks includes signal repeaters and bridges or routers.

LANs can be collectively be linked to create a WAN because they are smaller networks. This is done by using basic network hardware devices such as series of bridges and routers, which enable interconnectivity between separate LANs.

The contrasting features of Local Area Networks in comparison with Wide Area Networks is that the LAN date transfer rate is way faster, because WANs needs a leased line and a broad geographical area. While LANs cover a small geographical area and doesn’t rely on common carriers. A LAN network is more private than a WAN network, because a LAN needs a password validation as it also has specific user rights. Hardware resources are shared on a LAN, while on a WAN the focus is more on communications.

Also there is a difference in their network topology, in a LAN its often a peer-to-peer, which means that each client share resources with other workstations In the network. Whole WAN networks operate more on the client-to-sever topology basis with interconnected LANs, in other words all resources are provided and requested from the server.

One other major difference is that the cost to set up a LAN in comparison to WAN. A WAN network is relatively expensive, while setting up a LAN network connections are inexpensive even though the connection is high speed. In other words setting up one big LAN network in comparison to a small WAN network will be the cheaper option.

MAN is the acronym for metropolitan area network which is an another type of communication networks. It connects computers in a network; it’s usually larger than a LAN but smaller than a WAN. Often MAN is used to connect the computers of a city, but it may also be used to connect the machines of a University or similar institution. Some cities use MAN such as London, England, Geneva, Switzerland, and Poland. Not all computers in a MAN area need to be connected to the network, but the MAN usually connect as a whole to the internet, and thus provide a connection for those who choose to use this type of network. Efficiency and shared access are two advantages of using a MAN network, because all computer-owning residents in the area have equal ability to go on line. Some disadvantages are related to cost, politics, and security.

Circuit Switching & Packet Switching Networks:

A fundamental way of differentiating between network technologies is done on the basis of the method they use to determine the path between devices over which information will be sent and received. there are two different approaches: either a path that can be set up between the devices in advance, or the data would be sent as individual data elements over a variable path.

Circuit Switching:

In this networking method, between two devices a connection called the circuit will be set up, which will be used for the whole communication. The network is used to maintain information about the nature of the circuit. There is two different types of circuits: a fixed circuit that is always present, or a circuit that is created depending if its needed or no. even though in circuit switching through intermediate devices there is many potential paths that exist between the two devices communicating, only one path is used for any given dialogue.

The main example of a circuit-switched network is the telephone system. When you call someone and they pick up, you establish a circuit connection which starts passing the data, in a steady stream if desired. That circuit functions the same way regardless of how many intermediate devices are used to carry your voice. You can use it as long as you need it, and then after your done the circuit will be terminated. The next time you call, a new circuit will be established, which probably will use a different hardware than the first circuit did, depending on what hardware is available at that time in the network.

Packet Switching:

In this type of network, no specific/exact path is used for data transfer. Instead, the data is divided into small pieces called packets and sent over the network. The packets can be routed, combined or fragmented, as required to get them to their final destination. While On the receiving end, the process will be reversed; the data is read from the packets and re-assembled into the form of the original data. A packet-switched network is more related to the postal system than it is to the telephone system.

Comparing Packet Switching and Circuit Switching

One important issue in selecting a switching method is determining the network medium if it is shared or dedicated. Your phone line can be used for establishing a circuit because it is a dedicated network you are the only one using it. While in LANs a single shared medium and baseband signaling is used. If two devices were to establish a connection, they would reserve all the other devices for a long time. For that in a shared medium network it makes more sense to divide that into small packets and send them once at a time. Then, if two other devices want to communicate, their packets can be interspersed and everyone can share the network without any devices lock-out.

The reason why packet switching is becoming predominant nowadays is the ability to have more than one device communicating simultaneously without a dedicated path. However, there are some disadvantages of packet switching when compared to circuit switching. one is that since all data does not take the same, predictable path between devices, it is possible that some pieces of data may get lost in transmission, or won’t be received in a correct order. But In some situations the order doesn’t matter, while in others it is very important.

There is two types of packet switching:

Virtual Circuit Packet Switching

Virtual circuits allow packets to contain only the circuit number instead of the full destination address, so less router memory and bandwidth will be required. Thus the cost is relatively cheap.

Virtual circuit consumes time and resources because it requires a setup phase.

In virtual circuit, router only uses the circuit number to index into a table to find out where the packet are going.

Virtual circuit has some advantages in avoiding congestion in the subnet, because the resources can be reserved in advance, but the connection should be established.

The loss fault on the communication line vanish the virtual circuits.

In virtual circuit a fixed path is used during transmission, so traffic throughout the subnet can’t be balanced. This causes a congestion problem.

A virtual circuit is an implementation of a connection oriented service.

Datagram Packet Switching

Datagram circuits allow the packets to contain full address instead of the circuit number only, so a larger bandwidth is need. Thus datagram is relatively much more expensive.

Datagram circuit does not require a setup phase, so there will be no resources consumed.

In datagram circuit, a more complicated procedure is required to determine the where will the packet go.

In a datagram subnet, congestion avoidance is much more difficult.

The loss or fault on communication line can be easily compensated in datagram circuits.

Datagram allows the router to balance the traffic throughout the subnet, since the router can be changed halfway through any connection.

Asynchronous transfer mode (ATM)

It is a switching technology that assists and facilitates the movement of data from one point to another. ATM is one of the preferred technologies, because of its high efficiency of use, especially while using different hardware components. Unlike other types of technology, the efficiency and speed used in ATM makes it one of the most common network protocol standards in use nowadays.

The main advantage of ATM technology is the ability to transfer many various types of data at the same time. This is because as long as the bandwidth is available it will be utilized. While other type of technologies does not allow all the bandwidth to be used once a particular function is started. Therefore, ATM makes a very efficient way to transfer video files, pictures, e-mail and even live streaming video and audio.

ATM Services

There is three types of ATM services:

Permanent Virtual Circuits (PVC): A PVC provides direct connectivity between sites, so its similar to a leased line. Among its many advantages, PVC guarantees availability of a connection ,and does not require call setup procedures between switches before establishing a connection. Disadvantages of PVCs include static connectivity and the manual setup( Each piece of equipment between the source and the destination must be manually provisioned ). Furthermore, there is no network resiliency available while working with PVC.

Switched Virtual Circuits (SVC): A SVC is created and released dynamically. It remains in use only as long as the data is being transferred, which is similar to a telephone call. The dynamic call control requires a signaling protocol between the ATM endpoint and the ATM switch. The advantages of SVCs include connection flexibility and the autoamtix handling of a call setup by a networking device. While the disadvantages include the extra time and the overhead required to set up the connection.

connectionless service (similar to SMDS)

ATM Virtual Connections

ATM networks are fundamentally connection-oriented networks, which mean that a virtual channel (VC) must be set up across the ATM network before any data transfer. A virtual channel is relatively similar to a virtual circuit.)

Two types of ATM connections are:

Virtual Paths: which are identified by the virtual path identifiers.

Virtual Channels: which are identified by the combination of a virtual path identifier (VPI) and a virtual channel identifier (VCI).

To conclude, many type of communication are either IT communications or Interpersonal Communication, both types are used by people. Communication helps us to interact, make friends, be success at work, perform well in a team, and the most important thing is being able to use the latest technology in communicating. The one type of communication network used widely is the internet. Nowadays there isn’t a single person that does not have a wireless connection or an internet cable at home. People usually use the LAN network instead of WAN networks just as hotels or big firms do. Staying connected at the internet provides a person with a plenty of advantages, it made life way easier..