Comman LAN Architectures

Comman LAN Architectures

Common LAN Architectures, by the term we want to state the overall design of a LAN, included in the LAN architecture is the media access method and the physical components.

The three most common LAN architectures are Ethernet, Token ring and Arcnet.

Ethernet

Ethernet, the basis for the institute of Electrical and Electronic Engineers Inc(IEEE) standard 802.3, coas developed by Xerox, Digital Equipment Corporation , and Intel Ethernet network topologies are most commonly distinguished by the cable used.

The three cabling possibilities are Twisted pair, Thinnet and Thicknet.

Token Ring

A token ring network is an implementation of IEEE standard 802.5, the standard for token ring LAN’s.

The token passing access method, more than the physical cable layout, distinguishes token ring networks from other networks.

ArcNet

The Attached Resource Computer network (ArcNet) loosely maps to IEEE’s standard 802.4.

This specifies the standards for token passing bus networks using broadband cable.

ArcNet, however is a baseband network and can have a star or bus topology.

Ethernet

Originally known as Alto Aloha Network, Ethernet is a widely used local-area network (LAN) protocol originally created by Xerox PARC in 1973 by Robert Metcalfe and others (U.S. Patent # 4,063,220).

Being the first network to provide Carrier Sense Multiple Access / Collision Detection (CSMA/CD), Ethernet is a fast and reliable network solution that is still widely used today.

Below is a listing of different standards of Ethernet and additional information about each of them.

Ethernet II / DIX / 802.3

Ethernet II is a revised version of Ethernet rewritten by with Digital Equipment Corp, Intel and Xerox. Ethernet II, also known as DIX, (Digital, Intel, and Xerox) and 802.3.

Fast Ethernet / 100BASE-T / 802.3u

Fast Ethernet is also referred to as 100BASE-T or 802.3u and is a communications protocol that enables computers on a local-area network to share information with one another at rates of 100 million bits per second instead of the standard 10 million BPS.

Fast Ethernet works over Category 5 twisted-pair wiring.

There are two available types of 100BASE-T standards.

The first standard known as 100BASE-T utilizes CSMA/CD.

The second standard, known as 100VG-AnyLAN or 802.12, is similar to the other standard; however, it utilizes a different type of Ethernet frame to send its data.

100BASE-T is available in three different types of cable technologies:

1. 100BASE-T4 =

Utilizes four pairs of telephone-grade twisted-pair wire and is used for networks that need a low-quality twisted-pair on a 100-Mbps Ethernet.

2. 100BASE-TX =

Developed by ANSI 100BASE-TX is also known as 100BASE-X, 100BASE-TX uses two wire data grade twisted-pair wire

3. 100BASE-FX =

Developed by ANSI, 100BASE-FX utilizes 2 stands of fiber cable.

Ethernet SNAP

Ethernet SNAP is short for Ethernet SubNetwork Access Protocol and is a type of Ethernet protocol that enabled old and new protocols to be encapsulated in a Type 1 LLC.

Gigabit Ethernet / 1000BASE-T / 802.3z / 802.ab

Gigabit Ethernet is also known as 1000BASE-T or 802.3z / 802.3ab is a later Ethernet technology that utilizes all four copper wires in a Category 5 (Cat 5 & Cat 5e) capable of transferring 1 Gbps

10 Gigabit Ethernet / 802.3ae

10 Gigabit Ethernet is also known as 802.3ae is a new standard that supports 10.000 Gb/s.

1000BASE-CX

A copper cable gigabit Ethernet standard that is no longer used. This standard has been replaced by 1000BASE-T.

1000BASE-LX

A fiber optic gigabit Ethernet standard that operates over single-mode fiber.

1000BASE-SX

A fiber optic gigabit Ethernet standard that operates over multi-mode fiber, with typical distances of up to 550 meters (1804 feet)

Ethernet adapter

Ethernet adapter is a term used to describe an Ethernet network card used to connect a desktop computer to a network. If you are looking for network adapter

Ethernet: Thinnet (9 Base 2)

This topology is called Thinnet 9 Base 2.

The nickname derives from the size of the cable, which is roughly the size of a garden hose and too stiff to band with your hands.

A thin coaxial cable can transmit upto 9 Mbps roughly 200 meters over a baseband wire.

Thinnet networks generally use a local bus topology.

The cable used for this type of network is relatively inexpensive, and easy to install and configure.

As a result, this network is an economical way to support a small department or workgroup.

Ethernet: Thicknet (9 Base 5)

The main specification of the Ethernet topology commonly known as Thicknet 9 Base 5 are 9 Mbps, baseband and 500 meter segments.

Thicknet network generally use a bus topology. Thicknet was designed to support a backbone for a large department, or even an entire building.

Ethernet: Twisted-pair (9 Base T)

Twisted-pair 9 Base T, (9 Mbps, baseband, over-twisted-pair cable), is an Ethernet LAN that uses unshielded twisted pair cable to connect stations.

Most networks of this type are configured in a star pattern but internally use a bus signaling system like other Ethernet configurations.

Token Ring

Data on a token ring network is transmitted at either 4 or 16 Mbps, depending on the cable.

Network computers are connected by shielded and unshielded twisted pair cable to a wiring concentrator.

Each computer can be up to 90 meters from the multistation access unit (MAU) using shielded wire, or 45 meters using unshielded wire.

ArcNet

ArcNet is an easy to install and inexpensive baseband network that can have a star or a bus topology.

It typically uses co-axial cable and includes both active and passive hubs. Each work station is connected by cable to a hub.

The maximum cable length is from 120 meters to 606 meters depending on the type of cable and hub used.