Network Structure vs. Organizational Structure

Organizational structure closely resembles the intricate designs of the network. Networks give the ability for businesses to share resources to many users at once. Networks also can interconnect these resources to and from different geographic locations. LAN’s which are confined to one specific locations must be tailored to the company reducing total costs. Hardware and security is another function of a network that needs to be customized to the company. The network operating system is another key component with the structure of the company. NOS’s enable a company to limit resources according to users’ status in the business. LAN topologies also need to be custom to the company. Different topologies offer different means of data transmission throughout the network. And finally network designers must also tailor network security and hardware around the organizational structure. In conclusion, when a network is designed around the company’s organization, businesses can efficiently can accommodate growth and the company’s efficiency.

Companies Organizational Structure closely affects the design and implementation of a network and its design. Businesses must consider many different aspects to create an efficient network. For example, expansion, linking remote locations to a central headquarters, transmission media, security, internet connectivity, and network topologies.

Major businesses have identified some major areas of development and implementation; they are outlined as follows:

•Integrate all departments under a single scheme that applies to both sides.

•Formulate a purchasing policy for all hardware and software.

•Identify ways to link the different systems NOW allowing for migration over the new technology later.

•Identify training requirements for existing staff and personnel requirements for support staff.

Networks enable devices, which are geographically distant to be connected. For example, a user will wish to have the ability to data to a printer. Printers can be very expensive especially if they are color printers, it would be more cost effective to share this resource this can be achieved by interconnecting all the devices requiring access to the shared resource via a network.

Networks may provide an intelligent switching capability between the devices that need to print, or if a large print buffer was required this device became a print server. This was the first use for networks then blossomed with the introduction of new technology and print servers then joined by file servers, fax servers, and central servers. File servers and central servers are usually the same thing with the ability to give access to many differ applications to separate user terminals thus saving money and resources.

Networks are usually split into two different standards WANs and LANs. WANs are Wide Area Networks these are normal confided to the public sector: governments and universities. LANs are Local Area Networks these are normally found in the private sector: corporate and private companies. This paper will only deal with LANs.

A local area network (LAN) is a network which covers limited area and which generally provides a high data rate capability. A LAN is invariably confined to a single site (i.e., building or group of buildings) and provides for the exchange of information and efficient use of shared resources. In general a LAN should conform to a well-defined international standard, support a high data rate (typically 1 to 10 Mbps), have a maximum range of typically at least 500m but in some cases up to 10Km, be capable of supporting a variety of hardware independent devices, provide high standards of reliability and data integrity, exhibit minimal reliance on centralized components and controlling elements, maintain performance under conditions of high loading, allow easy installation and expansion, readily permit maintenance, reconfiguration and expansion.

In discussing networks the first thing to consider are the topologies that are used there are three main types: –

To be more specific, Bus is one of a family of network architectures ruled by a protocol called Carrier Sense Multiple Access/Collision Detect (CSMA/CD). In a CSMA/CD network all the stations are connected to a common bus. Therefore, all the stations are continuously listening to the messages transmitted on the bus, and each station collects the messages that were addressed to its address (Cisco press).

For a station to transmit a message, it first listens to the common media – “the Ether”. If the media is busy, no station introduces any messages. On the other hand, if the media is idle any station may transmit its messages. Sometimes, this arbitrary access to the common media can cause collisions among messages. Should a station detect that a message it transmitted collided with another, it would re-transmit the message after a while.

A Ring based network means that each station in the network is connected to its two neighbors by point-to-point links. This involves a simple and well-understood technology, on all types of media. Access to the network is based on the following rule: As long as all the stations are idle, a special bit pattern called a token circulates around the ring. For a station to be enabled to transmit a frame, it must first wait until the token arrives (Cisco press). The station then removes the token from the ring and starts transmitting. Since there is only one token, only one station can transmit at a given time, thus avoiding collisions on the channel. After the transmission is over, the station returns the token to the ring. The addressed station saves the message and changes an acknowledge bit. The transmitting station receives the acknowledgment and removes the message from the ring.

A star topology is one in which a central unit provides a link through which a group of smaller computers and devices is connected. In the star network, all interactions between different computers in the network travel through the host computer. The central unit will poll each to decide whether a unit has a message to send. If so, the central computer will carry the message to the receiving computer.

Star networks represent a very popular form of configuration for time-sharing systems in which a central computer makes available resources and databases for several “client” computers to share (Cisco press). As such, the star network is appropriate for systems that demand centralized control. The main advantage of star topology is its robustness. If a break does occur on a connection between the switch/ hub and a workstation, communication is only lost to that workstation. The disadvantage of the star network is that a processing problem in the central computer can be paralyzing to the entire system.

Advantages: “Easy to implement and extend, well suited for temporary networks that must be set up in a hurry, typically the least cheap topology to implement, and Failure of one station does not affect others.” (Frick)

Disadvantages: “Difficult to administer/troubleshoot, Limited cable length and number of stations, A cable break can disable the entire network; no redundancy, Maintenance costs may be higher in the long run, and Performance degrades as additional computers are added.” (Frick)

Advantages:”Growth of system has minimal impact on performance, and all stations have equal access.” (Frick)

Disadvantages: “Most expensive topology, Failure of one computer may impact others and Complex.” (Frick)

Advantages: “Easy to add new stations, Easy to monitor and troubleshoot, and Can accommodate different wiring.” (Frick)

Disadvantages: “Failure of hub cripples attached stations and more cable required.” (Frick)

This is installed on a server in a local area network and coordinates the activities of the network providing services to the computers and other devices attached to the network. Unlike a single-user operating system, a network operating system must acknowledge and respond to requests from many workstations, managing such details as network access and communications, resource allocation and sharing, data protection, and error control. The NOS is thus crucial in determining the overall effectiveness of the system as well as the transparency of the network in terms of access to the communications, file and print services offered by the network server. NOS should provide the following: Provide access to files via the file server on a multi-tasking basis, provide a user shell which will redirect network file request, provide file and record locking, include transaction support (read/modify/write), manage print queue, incorporate a significant element of fault tolerance(including redundant directory management, power supply monitoring, transaction tracking, and etc), incorporate differing levels of security and /or access control, provide network accounting facilities, permit inter-networking via internal and/or external bridges, incorporate message handling facilities for store and forward communications.

On a local area network (LAN), this is a computer running administrative software that controls access to the network and its resources, such as printers and disk drives, and provides resources to computers functioning as workstations on the network. For example, a single file server with a RAID level 1 fault tolerance with incorporated disk duplexing (Duplexing is where there are two disks and two disk controllers, enabling the system to remain in operation if a controller fails). (Kozierok) This type of server has many advantages: All round disk I/O performance is better than disk striping with parity and is better than disk mirroring during data reads, a mirrored pair can be split without loss of data, the boot partition can be duplexed, and the active system partition can be duplexed. If one disk controller fails the server remains, the system is designed to keep going in spite of disk errors, loss of a hard disk or loss of a disk controller.

Not all employees will require access to all the information available through the network. Such as users dealing with advertising should not have access to account or payroll information. All security permissions should be allocated on a logon basis and may be evaluated for each employee as to his/ her requirements. Generally the management will have access to all the information and other employees will have limited access. Also steps must be taken to prevent sensitive information being accessed by people not related to the business or competitors. Considerations for the security model are what information is considered sensitive, who should have access to the sensitive information, should the internal network be connected to a public network, if the internal network is to be connected to the internet, what information should be available to the public, should employees be allowed to alter their passwords, what will the host names be and who will have access to particular network resources.

As businesses expand a good, reliable link to the Internet is going to be essential. This can be done as a software addition to the server, by means of a suitable web browser such as Internet Explorer. Businesses can purchase or lease different types of media such as T1, T3, and ISDN links for access to the internet. However, internet access will have to tailor to those who need it such as management, accounts, admin and HR.

A Proxy Server Fire Wall can be used to provide Internet security a local network functions as normal but is separated from the Internet by a barrier created by the firewall. This helps to protect network resources from unauthorized use, and to prevent personnel, security and other commercially sensitive data from being accessed or transmitted without authorization.(How Firewalls …) Also with proxy servers can be statistically analyzed and monitored, thus enabling the administrator to tailor the network profile to the needs of the users.

The cabling used to connect the network PC’s, servers, hubs etc can prove to be a quite expensive part of the installation, mainly due to the quantity required. It is therefore important to make the right selection. There are three main types of media connection available: Twisted pairs (shielded and unshielded), Co-axial cable, and Fiber optic cable. Co-axial cable is used primarily for low noise applications. Fiber optic and shielded twisted pair cables have a higher resistance to RFI (radio frequency interference) and are generally used in RF hostile environments, a factor which makes them more expensive. However for most businesses the standard (and more cost effective) unshielded twisted pair cable will be adequate as most of the business operates in a relatively low RF environment.

While networks are the backbone of any business, networks provide a wide range of resources and data customized to the company structure. There are many different types of networks that offer different ways of sharing data and resources that must be centered on the company structure. With a well-designed network companies will become more efficient and can save money at the same time. Although well designed networks may be pricy initial startup-costs, networks provide the ability to be flexible with growth and who and where resources are shared too.