Components Of A Lan Network 6v53p

Components of a LAN Network :The components used to establish a local area network (LAN) have a variety of functions. The common unifying theme among them is that they facilitate communication between two or more computers. LAN components are configurable in a variety of ways, but a LAN always requires the same basic components.  Network Cards - At the most basic level, a network card is a component that allows the computer to communicate across a network. This component is frequently built into the motherboard of today's computers, but it can also be a separate card for use in a PCI slot, or part of an external unit that connects to the computer via a USB port. Network cards are further categorized according to whether they operate on wired or wireless networks. However, some cards do both wireless and wired networking.  Network Cables - Network cables are the physical lines used to carry information between computers in a wired LAN. The cables are labeled by their category and are commonly referred to as CatX--where X is the category number--cable. The most commonly used type in 2010 is Cat5, although other categories with different properties do exist.  Network Hubs - A network hub acts as a centralized point for data transmission to computers in a LAN. When data from one computer reaches the hub it is broadcast to every computer in the network regardless of where the data is intended to go. Network bandwidth on LANs using a network hub is shared, which means that four computers on a hub will each get one-quarter the total bandwidth available on the hub.  Network Switches - An alternative to the network hub is the network switch. Switches represent a newer networking technology that assigns each computer in the network a specific MAC address. This allows LANs using a network switch to route information to individual computers. Because network switches do not broadcast to every computer on the network, they can simultaneously allot their full bandwidth to each computer.  Routers - Unlike switches and hubs, network routers are used to connect networks to one another, rather than connecting computers in a single network. Routers can connect groups of computers that are separated by a wall or by an ocean. They are most commonly found in the home, where they facilitate the connection of home computers to the Internet; however, they can be used to connect networks of any kind. Most modern network routers are actually combination units that contain a router and a network switch, in addition to a handful of other networking-related tools such as a DH server and a firewall.

LAN Network Requirements :Creating a local area network is becoming more common in homes and small businesses. The basic requirements for a LAN are inexpensive hardware components and some software configurations on the computers. A home network is used to combine one or several machines. The network may even extend to wireless, where laptops are used to connect. However, to start the LAN setup, there are only some basic requirements.  Router or Hub - The router or hub are two types of hardware components in which the traffic is merged and computers are connected. A hub is just a central device, and the data is not filtered. Data is broadcast with no controls. However, a router is a more intelligent machine that routes data packets and sends them to the right section of the network. Routers can also be used as firewall protection from the Internet. Because routers have become relatively inexpensive, they are preferred over hubs.  Connection Method - The two most popular connection methods are hard wiring using ethernet cables or using wireless technologies. Most desktop networks use ethernet cables. These are inexpensive products that directly connect the network card of the computer to the router. Wireless technologies are used most often for laptops. However, to use a wireless network, the needs to set up a wireless router.  Network Cards - Network cards are hardware components added to machines that allow them to communicate. Network cards are used in any type of network. Wireless network cards are usually installed with any laptop purchase. However, hard wire network cards are also available for these machines. Network cards are inserted into a slot on a desktop that connects to the computer's motherboard. These are connected to the rest of the network using Ethernet cables that attach to the back of the card.

 Operating System Setup - The hardest part of a network design is setting up the software and operating system. The operating system needs to recognize the network card in the machine. It needs to have a protocol configured. The typical protocol on a network is T/IP. T/IP creates a unique address for the machine. The operating system retrieves an IP address from a server, or it can be defined in the network settings.  Security - Security is a major concern for any network . The of a small home network does not need to implement much security on the network. Most home networks are peer-to-peer, allowing s to share files without permissions. Larger networks require security. This is done by creating a domain and forcing s to to a server before accessing networking resources.

LAN Wiring & Pin outs :Crossed and Straight cables - when to use them :The following diagram shows the Normal use of Crossed and Straight cables (see also the notes below).

Standards Summary – The various standards can get a tad complicated and messy. We get occasional email requesting a summary of the standards - this is our attempt to provide a quick overview. Standard

Required Pairs

10M 100M 1000M Notes

10base-T

2 (1/2 and 3/6)

yes

yes

no

100m only if no cat 3/4 in run

100base-TX 2 (1/2 and 3/6)

yes

yes

no

100m only if no cat 3/4 in run

100base-T4 4 (1/2, 3/6, 4/5 and 7/8) yes

yes

yes

1000base-T 4 (1/2, 3/6, 4/5 and 7/8) yes

yes

yes

Functionally identical to 100base-T4

Category 5(e) (UTP) colour coding table : The following table shows the normal colour coding for category 5 cables (4 pair) based on the two standards ed by TIA/EIA We get occasional email about the difference between 568A and 568B wiring. Which one you use is a matter of local decision. These standards apply to the color code used within any SINGLE cable run - BOTH ENDS MUST USE THE SAME STANDARD. However, since they both use the same pinout at the connectors you can mix 568A and 568B cables in any installation.

10baseT Straight Cable (PC to HUB/SWITCH) :Straight cables are used to connect PCs or other equipment to a HUB or Switch. If your connection is PC to PC or HUB to HUB you MUST use a Crossed cable. The following cable description is for the wiring of both ends (RJ45 Male connectors) with the 568B category 5(e) wiring colors you could, of course, use the 568A colour scheme. Pin No.

strand color

Name

1

white and orange

TX+

2

orange

TX-

3

white and green

RX+

4

NC

*

5

NC

*

6

green

RX-

7

NC

*

8

NC

*

NOTE: Items marked * are not necessary for 10M LANs (10base-T) but since you will be moving shortly to 100MB LANs (won't you) you will save yourself a LOT OF TIME finding crappy cable (that you made) that does not work. Instead we suggest you wire to 100Base-T4 standards. After all you gotta stick the ends somewhere man. We use BLUE for 10base-T straight cables. NOTE: All our wiring is now done to the 100base-T4 spec which you can use with 10base-T networks - but NOT necessarily the other way around.

10baseT Crossed cable (PC to PC or HUB to HUB) :Crossed cables are used to connect PCs to one other PC or to connect a HUB to a HUB. Crossed cables are sometimes called Crossover, Patch or Jumper cables. If your connection is PC to HUB you MUST use a Straight cable. The following description shows the wiring at both ends (male RJ45 connectors) of the crossed cable. One end RJ45 Male

Other end RJ45 Male

1

3

2

6

3

1

4*

5*

5*

4*

6

2

7*

8*

8*

7*

NOTES: 1. Items marked * are not necessary for 10M LANs but since you will be moving shortly to 100MB LANs (won't you) you will save yourself a LOT OF TIME finding crappy cable (that you made) that does not work. Instead we suggest you wire to 100BaseT standards. 2. We use RED for crossed cables (or more commonly now a red heat-shrink collar at each end). 3. All our crossed wiring is done to the 100base-T4 spec which you can use with 10baseT networks - but NOT always the other way around.

100base-T Straight Cable (PC to HUB/SWITCH) :Straight cables are used to connect PCs or other equipment to a HUB or Switch. If your connection is PC to PC or HUB to HUB you MUST use a Crossed cable. The following cable description is for the wiring of BOTH ends (RJ45 Male connectors) with your category 5 wiring colors (TIA/EIA 568A or 568B though the example uses 568B colors). Pin No.

conductor color

Name

1

white and orange

TX_D1+

2

orange

TX_D1-

3

white and green

RX_D2+

4

blue

BI_D3+ **

5

white and blue

BI_D3- **

6

green

RX_D2-

7

white and brown

BI_D4+ **

8

brown

BI_D4- **

We use BLUE for 100baseT straight cables. NOTES: 1. Wires marked ** are ABSOLUTELY NECESSARY for 100Base-T4 networks - used when any combination of category 3/4/5 cables are present, when using 1000base-T (GigE) and MAY be required for Power-over-Ethernet (PoE) - see below. 2. Wires marked ** are not essential for 100Base-TX (using cat 5/5e ONLY cables) and CAN be used for other purposes, for example, telephony but, .. beware .. read this FAQ and our LAN plus Telephony article before you wire your entire neighbourhood for surround sound. 3. The Power-over-Ethernet spec (802.3af) allows three schemes where power may be supplied. Two of these schemes use pairs 4,5 and 7,8 (marked ** in above table) for power (called Midspan PSE and Alternative B or Mode B), one scheme uses ONLY pairs 1,2 and 3,6 (Endpoint PSE, Alternative A or Mode A) for both signals and power. Depending on which scheme you use pairs 4,5 and 7,8 may be required. 4. Gigabit Ethernet requires all 4 pairs (8 conductors). 5. All our wiring is now done to the 100base-T4 spec which you can use with 10baseT networks - but NOT the other way around.

100base-T Crossed cable (PC to PC or HUB to HUB) :Crossed cables are used to connect PCs to one other PC or to connect a HUB to a HUB. Crossed cable are sometimes called Crossover, Patch or Jumper cables. If your connection is PC to HUB you MUST use a Straight cable. The following description shows the wiring at both ends (male RJ45 connectors) of the crossed cable. Note: The diagrams below shows crossing of all 4 pairs and allows for the use of cat3/4 cables with 100m LANs (100base-T4). Pairs 4,5 and 7,8 do not NEED to be crossed in 100base-TX wiring. See notes below.

We use RED for crossed cables (or more commonly now a red heat-shrink collar at each end). NOTES: 1. All our crossed wiring is now done to the 100base-T4 spec (uses all 4 pairs, 8 conductors) which you can use with 10base-T networks - but NOT necessarily the other way around. 2. Many commercial 100m LAN cables seem not to cross pairs 4,5 and 7,8. If there is no cat3/4 wiring in the network this perfectly acceptable. 3. Gigabit Ethernet uses all 4 pairs so requires the full 4 pair (8 conductor) cross configuration (shown above). 4. If you are using Power-over-Ethernet (802.3af) then Mode A or Alternative A uses pairs 1,2 and 3,6 for both signals and power. Mode B or alternative B uses 4,5 and 7,8 to carry power. In all cases the spec calls for polarity insensitive implementation (using a diode bridge) and therefore crossing or not crossing pairs 4,5 and 7,8 will have no effect.

1000base-T Gigabit Ethernet :1000base-T is the copper based version of the gigabit Ethernet standard defined by 802.3ab which, since it is over 6 months old, is available free of charge from the enlightened IEEE. Great work. In ing, if you want to see sophistry raised to an art form read the EIA's justification for charging for their specifications. (Note: The original EIA statement is unfortunately no longer avilable on-line. This is a great loss to both the development of the English language in general, and comedy writing in particular.) The following notes apply to the 1000base-T spec: 1. The standard defines auto-negotiation of speed between 10, 100 and 1000 Mbit/s so the speed will fall to the maximum ed by both ends - ensuring inter-working with existing installations. 2. The cable specification base-line is ANSI/TIA/EIA-568-A-1995 (which you have to pay for). This means that if you know your cat5 cable was manufactured to this standard (there was a lower spec 1991 version of this specification) then it will Gigabit Ethernet. Cat5 cable manufactured to the old specification may work or it may not - you need to run some tests. Cat5e and cat6 being higher spec cables will clearly Gigabit Ethernet. 3. Maximum runs are the standard 100m (~300ft). 4. Gigabit Ethernet uses all 4 pairs (8 conductors). The transmission scheme is radically different (PAM5 a 5 level amplitude modulation scheme) and each conductor is used for send and receive. 5. Crossed Gigabit Ethernet cables must cross all 4 pairs. Shielded Twisted Pair :Shielded Twisted Pair (STP) comes in a variety of formats. It is typically used in three applications: 1. Where there is significant EMI (Electro-Magnetic Induction) in the environment such as caused by high-powered electric motors (such as in elevator shafts), flourescent lighting etc. Additionally where there is significant Alien Crosstalk (ANEXT) such as in very high speed (gigabit and 10gb) LANs. In this case the ethernet signals in the cable require protection against external interference from either adjacent pairs or the environment. 2. Where there is extremely sensitive electrical/electronic equipment in the surrounding environment or where security requirements demand elimination of eavesdropping possibilities from radiated LAN signals (TEMPEST). In this case the ethernet signals in the shielded cable are contained and prevented from polluting, or escaping into, the external environment. 3. Where maximum performance - either speed or distance - is required. As Ethernet speeds continue to increase either fiber or Shielded Twisted Pair is becoming increasingly common, for instance, to reach 100m distances at 10Gb speeds on copper will require shielded cable (limited to 55m for UTP). Shielded cable comes in three broad types with a confusing range of terminology: 1. Where there is a single foil (FTP - Foil Twisted Pair) or braided (ScTP - Screened Twisted Pair) shield inside the jacket covering all four pairs. Suitable for applications 1 and 2 above. 2. Where there is a foil shield covering each pair. This is frequently refered to as PiMF (Pairs in Metal Foil) and is designed primarily to eliminate Alien Cross-talk (ANEXT) from adjacent pairs. Suitable for application 3 above. 3. Where there is a foil shield covering each pair and a (Foil or Braided) shield covering the whole cable. This is frequently refered to as SSTP (Double Shield Twisted Pair) or even PiMF - since many manufacturers also add a jacket shield to foil covered pair cables. Suitable for applications 1, 2 and 3 above.

In almost all cases there is a single ground wire (called a drain) which allows for connection to secondary grounding sources. The diagram below illustrates the differences:

Notes: 1. Shielded cable of any variety has a greater diameter than UTP and will therefore occupy more space in cable ducting and raceways. 2. Connecting shielded cable is more complex and time consuming - but not execessively so - than conventional UTP. Manufacturers specifications vary enormously, expecially with respect to grounding, and should be followed closely. 3. In shielded cable installations the jacks and receptacles are typically made of metal and the cable shield (foil or braid) is connected electrically to the connector and thence through the metal receptable to a suitable ground provided by the end equipment. 4. Foil covered pairs are typically not connected to ground and thus provide only alien crosstalk immunity from adjacent pairs (ANEXT). 5. Manufacturers specifications and measurements suggest that shielded cables do NOT create antenna effects - indeed experiments show that UTP creates a substantially greater antenna effect (~40db) over correctly grounded shielded cables. 6. Even ungrounded shielded cables provide better performance (by ~20db) than conventional unshielded twisted pair (UTP). 7. The drain wire provides a secondary or auxiliary ground method in cases where metallic path grounding is provided by the connectors and, as such, is optional. In cases where metal connectors are not being used (there is no grounding via the connectors) the drain wire may be used as the primary grounding method and needs to be routed independantly to a suitable ground. The drain wire (cable ground) needs to be exposed before connector. This process could require a considerable length of exposed drain wire depending on the location of the ground source. A plastic insulating sheath should be placed over the drain wire to minimize electrical hazards. 8. In all cases where both ends of a shielded cable are gounded this should be done using a common (building) ground to avoid ground potential loops which if they exceed 1V will have serious effects on cable performance. It is also important to note that 'grounding both ends' means final equipment terminations. Intermediate jacks or faceplates must maintain electrical continuity throughout the cable run but are not themselves grounded. This app note from AMP provides a detailed explanation.