• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14
  15. 15
    15

Computer network concepts and principles - arcnet.

Extracts from this document...

Introduction

UNIVERSITY OF NAIROBI COMPUTER NETWORK CONCEPTS AND PRINCIPLES ARCNET Mungai Andrew Gichuho (JULY 2003) HISTORY Datapoint Corporation introduced ARCNET, classified as a local area network (LAN), as office automation in the late 1970s. ARCNET is coined from two words i.e. ARC & NET. ARC in full is attached resource computer and NET is from the word network. So ARCNET in full means attached resources computer network. ARCNET's use as an office automation network has diminished but continues to find success in the industrial automation industry because its performance characteristics are well suited for control. It is very robust, fast and provides deterministic performance. In addition, it can span long distances thus making it a suitable fieldbus technology. The term fieldbus is used in the industrial automation industry to signify a network consisting of computers, controllers and devices mounted in the "field". ARCNET is an ideal fieldbus that delivers a message in predictable time fashion because of its token-passing protocol that it uses. ARCNET packet lengths vary from 0 to 507 bytes with little overhead and high data rate, typically 2.5 Mbps, yields quick responsiveness to short messages needed by feldbus. It has a built-in CRC-16 (cyclic redundancy check) error checking and supports several physical cabling schemes including fiber optics. The data link protocol is self-contained in the ARCNET controller chip. Network functions such as error checking, flow control and network configuration are done automatically without software intervention. In terms of the International Organization of Standards OSI (Open Systems Interconnect) Reference Model, ARCNET provides the Physical and Data Link layers of this model. In other words, ARCNET provides for the successful transmission and reception of a data packet between two network nodes. A node refers to an ARCNET controller chip and cable transceiver connected to the network. Nodes are assigned addresses called MAC (medium access control) IDs and one ARCNET network can have up to 255 uniquely assigned nodes. ...read more.

Middle

Coaxial is relatively inexpensive and provides the highest propagation factor compared to all other media. ii) Twisted-pair Twisted-pair cable is inexpensive and convenient to user and easy to terminate though it exhibits greater attenuation and therefore limited distance capability. Its compatible with several transceivers though IBM type 3 is the most recommended. iii) Fiber Optic: Offers the greatest distance bur requires more attention to its application. It comes in a variety of cables and cable pairs. Fiber optics span the greatest distance with a low propagation factor. Its installation should be evaluated to ensure that it is within ARCNET limits. NB: All cable installations must comply with the ISO - OSI ordinance. iv) Coaxial Cable: Good Price Vs Performance The original ARCNET called for coaxial cable as the formal medium between hubs and NIMs. Transceivers were developed to remove hubs but the coaxial cable remained. The two transceivers: 1. Coaxial cable for distributed star systems 2. Coaxial bus for hubless systems. P1 and P2 Signaling: ARCNET controllers develop two signals, P1 and P2; where P1 and P2 are negative signals of 100nanoseconds in duration with P2 following P1 when operating at 2.5mbps data rate. ARCNET controllers transmit a signal when logic 1 is transmitted, with logic 0 rendering the line idle as no pulses are sent. Star Vs Bus: The coaxial star transceiver and the coaxial bus transceiver both receive P1 and P2 signals and generate dipulse signals. However, the star transceiver represents a low impedance at all times while the bus transceiver represents high impedance when idle allowing for multiple transceivers to be attached to a common bus. TWISTED-PAIR - INEXPENSIVE AND SIMPLE TO USE. Twisted-pair in ARCNET is quite inexpensive and easy to use as well as top terminate. It is actually a very popular cabling technology. Compared to the coaxial cable, it has a higher attenuation and modular jacks and plugs are used to interconnect segments. ...read more.

Conclusion

and the reconfiguration time (the time a node waits before initiating a reconfiguration burst). SOFTWARE STANDARDS OSI MODEL: This model describes the various layers of services that may be required in order for two or more nodes to communicate to one another. ARCNET conforms to the physical layer and the medium access control portion of the data link as defined by IEEE. All the layers above the data link layer collectively are called the protocol stack and the number of services available or used by differing applications vary. The software required to bind a network interface module to a protocol stack is called a driver and many different drivers exist for ARCNET. Collapsed Stack or Null Stack: The application layer is tied directly to the Data Link layer. It is a popular approach for embedded networking. Control Link - SMSC developed IEEE 802.2 services that provide logical link control (LLC) above the MAC sub-layer. NetBios - Used with several peer-to-peer network operating systems and, frequently, the interface to ARCNET systems. Net BEUI - The NetBios Extended User Interface is both a NetBIOS interface and protocol. TCP/IP - TCP functions at the transport layer and IP functions at the Network Layer. The Protocols provide ARCNET connectivity to the Internet. IPX/SPX - Microsoft's version is called NWLink. NDIS - Network Driver Interface Specification is a driver specification, which allows an ARCNET to bind to NetBEUI, IPX/SPX or TCP/IP or any other protocol for which an NDIS compatible protocol driver has been written. ODI - Open Data link Interface. N/B: When installing ARCNET adapters, it should be ensured that the proper driver is available from the adapter supplier or the equipment OEM who specifies the ARCNET adapter. Conclusion: ARCNET Trade Association (ATA): This was formed in 1987 for the dual purpose of developing working standards for ARCNET and promoting the use of ARCNET as a viable networking technology. Besides endorsing ARCNET NetBIOS, the ATA is working with three standards: 1. ANSI/ATA 878.1 local Area Network: Token Bus 2. ATA 878.2 ARCNET Packet Fragmentation Standard 3. ATA 878.3 Encapsulation Protocol Standard. Site: ata@arcnet.com or www.arcnet. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Information Systems and Communication section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Information Systems and Communication essays

  1. Marked by a teacher

    Database Coursework on a Vehicle Rental System: Analysis

    5 star(s)

    customers, and manufacturers are continuously changing due to a multitude of factors. As such, it is very important that the business keeps track of these changes and amends existing data structures and records as appropriate. There are many instances in which details held by the system will have to be amended.

  2. Peer reviewed

    Networking Systems. Network Cabling, Network Interface Cards,Network Connectivity

    3 star(s)

    One potential benefit is that Cat5 can only be used for up to 100m this would be suitable for a medical centre, using Cat5 will also lower costs. * How will cost be a major factor? Cost is and will always be a major factor as a small medical centre will usually have a smaller budget to work on.

  1. ict as level coursework

    Invoices need to be produced quickly The beauty of this system is that all information that is being entered on the 'buy products' user form are automatically transferred on the invoice so information does not have to be entered twice which saves time.

  2. Free essay

    This research report will present a brief history of the Internet, focusing on some ...

    Ray Tomlinson's basic invention in 1971 has advanced dramatically to what we now use in daily life. Taking into consideration daily communication, we in the 21st century would struggle to function without the use of email. Bosses contact their employees, employees contact each other and clients, friends contact friends - basically everyone uses email.

  1. The hospitality industry is in a unique position for the creation of an automated ...

    Most of the large firms apply JIT purchasing for most of their outsourced products, subassemblies and raw materials. JIT purchasing is beneficial for most of the firms that implement all the prerequisites of JIT philosophy fully. A. Housekeeping It would seem obvious that an organized and uncluttered work place is conducive to efficient and effective manufacturing.

  2. From the e-commerce strategy you gave me earlier I understand that by having a ...

    You will need things like:- I. Information risks assessments. II. Have a culture of security awareness within the organisation (BAD). III. A responsible and designated person for information security, who has the necessary authority and equipment available to them to fulfil this role. The staff in your organisation should be familiar with the company's security policies

  1. Computer Network

    Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites. A WAN also consists of a number of LANs connected over a large geographical area - this could be more than one location in the country - London Sheffield or around the world.

  2. Communication & Employability Skills for IT. OCR Cambridge Technicals Unit 1 LO1-P1

    student data but however there are restrictions and limitations to the teachers. Teacher with the highest rank such as the Head Teacher and the Head of Human Resources can even have access to the teacher?s data as well, whilst ordinary teachers cannot.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work