Wednesday 2 May 2012

Network Protocols


Introduction
There are several different types of networks which have their own features and technologies to enable them to establish a connection. Here is a list of some of the types of networks; PAN (Personal Area Network), LAN (Local Area Network), MAN (Metropolitan Area Network), (WAN) Wide Area Network. Each of these types of networks has their own advantages and disadvantages.
Personal Area Network
A personal area network normally uses equipment and technologies which are used by one person and enable other systems to use the devices on the network an example of the type of devices which would commonly be used on this network are printers.
Local Area Network
A local area network (LAN) supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home. Local area networks are mostly made up of cheap hardware such as Ethernet cables and network adaptors. A local area network can be made up of a minimum of two computers while large LAN’s can include thousands of computers and then they can be divided into separate logical groups called subnets. The internet protocol called “Class A" LAN can in theory accommodate more than 16 million devices organized into subnets.
Wide Area Network
A wide area network typically consists of two or more local area networks. Computers connected to a wide-area network are often connected through public networks, such as the telephone line system or satellites.
Protocols
There are various rules that protocols that are put in place to manage the communication between computers on a network. These rules include guidelines that regulate the access method, topologies, types of cabling, and speed of data transfer. Different protocols offer different speeds and range so this reflects in the topology in which it is used in. For example longer ranged topology would use a fast Ethernet topology which uses a fibre optic cabling.
Protocols between networks are designed and illustrated and layered in the OSI model. Different network methods have their place in the OSI model The LAN protocols can be put under the physical and data link layers of communications over various LAN media such as Ethernet wires and wireless radio waves. The WAN protocol is for the lowest three layers and defines communication over various wide-area media, such as fibre optic and copper cables
Protocol
Cable
Speed
Topology
Ethernet
Twisted Pair, Coaxial, Fiber
10 Mbps
Linear Bus, Star, Tree
Fast Ethernet
Twisted Pair, Fiber
100 Mbps
Star
LocalTalk
Twisted Pair
23 Mbps
Linear Bus or Star
Token Ring
Twisted Pair
4 Mbps - 16 Mbps
Star-Wired Ring
FDDI
Fiber
100 Mbps
Dual ring
ATM
Twisted Pair, Fiber
155-2488 Mbps
Linear Bus, Star, Tree

Importance of Network Protocols
Network Protocol is needed because the message or data sent by networks have to reach their destinations by going through different networks of different structure and different platform. Network protocols are performing the duty to make our sent data compatible to the new networks. They also help create a standard of communication, such as TCP/IP. This is used to enable different operating systems to talk to each other over a network. So the main significance of the network protocols is compatibility of networks over the internet.

WAN wide area networks connect to organisations which are located nationwide. A wide are network would likely be used to connect smaller local area networks to other Local area networks which may be located further away for example in another country.
MAN metropolitan area network. Authorities and finance would use this type of network. This type of network would typically be used to connect separate offices around a city with extremely fast transfer speed.
PAN personal area network would use network medians such as Bluetooth. Personal area networks typically involve a portable device which has internet connectivity such as a PDA. You can use these networks to transfer files including email and calendar appointments, digital photos and music. The range of a PAN network would typically only over the distance of 10 metres.
There are many useful services that are featured in networks which include enable schools and businesses to share resources with all the computers connected to the network. This is perfect for businesses which want to relay important files and documents to all the employees with ease. The way in which this is done is simply by uploading files to a central server which can then be accessed by everyone on the network. Without this feature it would be considerably harder and take considerably longer for businesses to get files to employees. This feature is also perfect for businesses which are looking to save money by using fewer resources such as paper because files can simply be completed on a computer then saved and sent through the network without needing to print the documents.
Networks also have the capacity to provide their own private email service. This is perfect for businesses and schools as it enables an email system to be created in the internal network which ultimately enables you to send emails to users in the network. An example would be to have a boss of a business send a mass message to all employees without needing to stage a meeting or print out loads of pages. This saves money, easier and consumes considerably less resources.
Telecommunication services are useful in networks as it enables businesses to implement other connection mediums such as wireless technology so that employees can access the network in a remote or mobile location as long as they are in the network range. For example they can use laptops anywhere in the building without being hindered by the length of their network cable. Wireless computers can also be linked together which is useful if a computer needs to be controlled remotely by another computer for maintenance needs.
This way of connecting the business together makes the network pretty secure from external intrusions as well as enabling the business to safely relay information and communicate at a considerably lower cost that if it was done other ways.

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