Setting Up A Network

The setting up of a simple network is explored here.

Ethernet       Ethernet, one of the pivotal technologies that made Local Area Networks possible, was developed in the 1970s by Digital, Intel and Xerox. This original design is often referred to by the initials of its creators - DIX. Ethernet works by connecting an almost unlimited number of devices to the same cable. Usually, a host can just transmit whenever the cable is not is use. In the relatively uncommon case where two devices start transmitting at the same time, a collision occurs. Both senders then wait a random amount of time before transmitting again. In any case, every device on the cable can receive every packet, but discards all those not addressed to it. This scheme, one of many that can regulate access to a hardware medium, is referred to CSMA/CD, an acronym for Carrier Sense, Multiple Access / Collision Detect. 

    Originally Ethernet operated at 10Mbps per second, and its packets are between 64 and roughly 1500 bytes in length. A 6-byte address is used, which is divided into a 3-byte vendor ID and a 3-byte vendor-defined field. Ethernet manufacturers are assigned a unique vendor ID, and are then responsible for insuring that all of their devices have unique addresses in the last 3 bytes. An all-ones address is interpreted to mean broadcast, and all hosts attached to the cable process such a packet. A group of addresses are assigned for multicast use, and most newer Ethernet cards permit software to select a subset of the multicast addresses for reception. DIX Version 2 Ethernet has a type field which indicates what type of data is contained in the packet. A standard type field (0800 hex) indicates that an IP packet begins at the end of the Ethernet header. Documented in RFC 894. IEEE 802 Ethernet defines an Ethernet-specific header (802.3), and a media-independent header (802.2). An 802.2 extension called SNAP permits a DIX type code to be specified. Encapsulating IP with this scheme produces a packet starting with an 802.3 header, then an 802.2 header, then a SNAP header, then the IP packet. RFC 1042. IEEE 802.3 Ethernet is sometimes used directly, without the 802.2 or SNAP headers. This makes packets smaller, but since the 802.3 header does not contain a type field, this method can't be used with multiple protocols on the same Ethernet, or confusion would result. Since IP requires ARP to operate over Ethernet, this method is never used. However, it is common for NetWare. Using repeaters, bridges, and routers, it's fairly simple to to interoperate Ethernet implementations to the point of sharing DIX and IEEE 802 frames on the same cable.

Ethernet Cabling     Several types of cabling are used for Ethernet

10 Base 5, or Thicknet, uses a single 75-ohm coaxial cable in a bus topography, connecting each device with a "vampire tap" clamped over a hole drilled in the cable. Segments may be up to 500 meters in length.

10 Base 2, or Thinnet, uses a string of RJ-58 coaxial cables in a bus topography, with BNC T connectors attached to each device, and 52-ohm terminators at each end. Maximum segment length is 200 meters.

10 Base T uses twisted pair wiring (preferably shielded) in a star topography, with each segment connecting a single device to a repeater, usually referred to as a hub. Unlike other Ethernet cabling schemes, which specify physical cable types, 10-Base-T specifies requirements for various electrical properties of the wiring. The only reliable way to meet these requirements is by checking wiring with a cable tester, an essential tool for large 10-Base-T installations.

10 Broad 36, the only broadband Ethernet design, permits operation over closed-circuit cable television systems, requiring three adjacent TV channels to be allocated for a single Ethernet segment.

Fiber optic Ethernet segments based on optical fiber usually for large distances.

Hardware Requirements.     To setup a network the folloing hardware is required.

    a.    Ethernet card.

    b,    UTP CAT 5 Cable

    c.    Crimping Tool

    d.    RJ 45 connectors.

    e.    A PC with a free PCI Slot.

Software  Requirements.    

    a.    Ethernet Card Software Driver.   

    b.    An IP Address (In an internal LAN ie not connected to the internet 192.168.000.xxx can be used )

    c.    Operating System Disk.

Steps.    

    a.    Install the Ethernet LAN card and load the software driver. Configure the setting for the card to include the IP address assigned to the machine and reboot.

    b.    Crimp the RJ 45 Connector to the UTP cable with the 1,2,3,6 pairs being common on both sides of the cable.

    c.    Plug in the cable into the card and the Hub the Link LED on the Card and hub should light up indicating a correct cable and connector.

    d.     Now the setup is complete and the PC is on the local Network.