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LAN Technologies. LAN TECHNOLOGIES. LAN Technologies. Technology Options. Ethernet Fast Ethernet Gigabit Ethernet 10 Gig Ethernet WLAN. LAN Technologies. Media Access. Ethernet and Wi-Fi are both “multi-access” technologies Broadcast medium, shared by many hosts
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LAN Technologies LAN TECHNOLOGIES
LAN Technologies Technology Options • Ethernet • Fast Ethernet • Gigabit Ethernet • 10 Gig Ethernet • WLAN
LAN Technologies Media Access • Ethernet and Wi-Fi are both “multi-access” technologies • Broadcast medium, shared by many hosts • Simultaneous transmissions will result in collisions • Media Access Control (MAC) protocol required • Rules on how to share medium • The Data Link Layer is divided into two Part MAC Media Access Control) Sublayer and LLC (Logic Link Control) Sublayer
LAN Technologies 802.3 Ethernet • Carrier-sense multiple access with collision detection (CSMA/CD). • CS = carrier sense • MA = multiple access • CD = collision detection • Base Ethernet standard is 10 Mbps. • 100Mbps, 1Gbps, 10Gbps standards came later
LAN Technologies Ethernet CSMA/CD • CSMA/CD (carrier sense multiple access with collision detection) media access protocol is used. • Data is transmitted in the form of packets. • Sense channel prior to actual packet transmission. • Transmit packet only if channel is sensed idle; else, defer the transmission until channel becomes idle. • After packet transmission is started, the node monitors its own transmission to see if the packet has experienced a collision. • If the packet is observed to be undergoing a collision, the transmission is aborted and the packet is retransmitted after a random interval of time using Binary Exponential Backoff algorithm.
LAN Technologies Ethernet Address • End nodes are identified by their Ethernet Addresses (MAC Address or Hardware Address) which is a unique 6 Byte address. • MAC Address is represented in Hexa Decimal format e.g 00:05:5D:FE:10:0A • The first 3 bytes identify a vendor (also called prefix) and the last 3 bytes are unique for every host or device
LAN Technologies Ethernet Frame Structure • Preamble: • 7 bytes with pattern 10101010 followed by one byte with pattern 10101011 • Used to synchronize receiver, sender clock rates • Addresses: 6 bytes, frame is received by all adapters on a LAN and dropped if address does not match • Length: 2 bytes, length of Data field • CRC:Cyclical Redundancy Check 4 bytes generated using CR-32, checked at receiver, if error is detected, the frame is simply dropped • Data Payload: Maximum 1500 bytes, minimum 46 bytes • If data is less than 46 bytes, pad with zeros to 46 bytes Length
LAN Technologies Ethernet • 10 Base 5 (Thicknet) (Bus Topology) • 10 Base 2 (Thinnet) (Bus Topology) • 10 Base T (UTP) (Star/Tree Topology) • 10 Base FL (Fiber) (Star/Tree Topology)
LAN Technologies Ethernet BUS Topology Repeater
LAN Technologies Ethernet STAR Topology Hub
LAN Technologies Ethernet • Physical Media :- • 10 Base5 - Thick Co-axial Cable with Bus Topology • 10 Base2 - Thin Co-axial Cable with Bus Topology • 10 BaseT - UTP Cat 3/5 with Tree Topology • 10 BaseFL - Multimode/Singlemode Fiber with Tree Topology • Maximum Segment Length • 10 Base5 - 500 m with at most 4 repeaters (Use Bridge to extend the network) • 10 Base2 - 185 m with at most 4 repeaters (Use Bridge to extend the network) • 10 BaseT - 100 m with at most 4 hubs (Use Switch to extend the network)
LAN Technologies Fast Ethernet • Fast Ethernet is an extension of the existing Ethernet standard. • It runs on UTP data or optical fiber cable and uses CSMA/CD in a star wired bus topology, similar to 10BASE-T where all cables are attached to a hub.
LAN Technologies Fast Ethernet • Fast Ethernet provides compatibility with existing 10BASE-T systems and thus enables plug-and-play upgrades from 10BASE-T. • Fast Ethernet is sometimes referred to as 100BASE-X where X is a placeholder for the FX and TX variants.
LAN Technologies Fast Ethernet → Copper • 100BASE-T is any of several Fast Ethernet standards for twisted pair cables, including: -100BASE-TX (100 Mbit/s over two-pair Cat5 or better cable), -100BASE-T4 (100 Mbit/s over four-pair Cat3 or better cable, defunct), -100BASE-T2 (100 Mbit/s over two-pair Cat3 or better cable, also defunct). The segment length for a 100BASE-T cable is limited to 100 metres (as with 10BASE-T and gigabit Ethernet). All are or were standards under IEEE 802.3. Almost all 100BASE-T installations are 100BASE-TX.
LAN Technologies Fast Ethernet • 100BASE-TX is the predominant form of Fast Ethernet, and runs over two wire-pairs inside a category 5 or above cable (a typical category 5 cable contains 4 pairs and can therefore support two 100BASE-TX links). Like 10BASE-T, the proper pairs are the orange and green pairs (canonical second and third pairs) in TIA/EIA-568-B's termination standards, T568A or T568B. These pairs use pins 1, 2, 3 and 6.
LAN Technologies Fast Ethernet • RJ-45 Wiring (TIA/EIA-568-B T568B)
LAN Technologies Fast Ethernet • The configuration of 100BASE-TX networks is very similar to 10BASE-T. When used to build a local area network, the devices on the network (computers, printers etc.) are typically connected to a hub or switch, creating a star network. Alternatively it is possible to connect two devices directly using a crossover cable.
LAN Technologies Fast Ethernet → fiber • 100BASE-FX is a version of Fast Ethernet over optical fiber. • It uses a 1300 nm near-infrared (NIR) light wavelength transmitted via two strands of optical fiber, one for receive(RX) and the other for transmit(TX). • Maximum length is 400 metres (1,310 ft) for half-duplex connections (to ensure collisions are detected), and 2 kilometres (6,600 ft) for full-duplex over multi-mode optical fiber.
LAN Technologies Fast Ethernet • 100BASE-SX is a version of Fast Ethernet over optical fiber. It uses two strands of multi-mode optical fiber for receive and transmit. It is a lower cost alternative to using 100BASE-FX, because it uses short wavelength optics which are significantly less expensive than the long wavelength optics used in 100BASE-FX. 100BASE-SX can operate at distances up to 550 metres (1,800 ft).
LAN Technologies Fast Ethernet • 100BASE-SX uses the same wavelength as 10BASE-FL, the 10 MBit/s version over optical fiber. • Unlike 100BASE-FX, this allows 100BASE-SX to be backwards-compatible with 10BASE-FL.
LAN Technologies Fast Ethernet • 100BASE-BX is a version of Fast Ethernet over a single strand of optical fiber (unlike 100BASE-FX, which uses a pair of fibers). Single-mode fiber is used, along with a special multiplexer which splits the signal into transmit and receive wavelengths. -Distances can be 10, 20 or 40 km. • 100BASE-LX10 is a version of Fast Ethernet over two single-mode optical fibers. - It has a nominal reach of 10 km.
LAN Technologies Gigabit Ethernet • Gigabit Ethernet (GbE or 1 GigE) is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second, as defined by the IEEE 802.3-2008 standard. • Half-duplex gigabit links connected through hubs are allowed by the specification but in the marketplace full-duplex with switches is normal.
LAN Technologies Gigabit Ethernet • Gigabit Ethernet was deployed in high-capacity backbone network links (for instance, on a high-capacity campus network). • In 2000, Apple'sPower Mac G4 and PowerBook G4 were the first mass produced personal computers featuring the 1000BASE-T connection. • It quickly became a built-in feature in many other computers. • As of 2009 Gigabit NICs (1000BASE-T) are included in almost all desktop and server computer systems.
LAN Technologies Gigabit Ethernet • Higher bandwidth 10 Gigabit Ethernet standards have since become available as the IEEE ratified a fiber-based standard in 2002, and a twisted pair standard in 2006. • As of 2009 10Gb Ethernet is replacing 1Gb as the backbone network and has begun to migrate down to high-end server systems.
LAN Technologies Gigabit Ethernet • 1 Gbps bandwidth. • Uses same CSMA/CD media access protocol as in Ethernet and is backward compatible (10/100/100 modules are available). • 1000BaseT (UTP), 1000BaseSX (Multimode Fiber) and 1000BaseLX (Multimode/Singlemode Fiber) standards. • Maximum Segment Length • 1000 Base T - 100m (Cat 5e/6) • 1000 Base SX - 275 m (Multimode Fiber) • 1000 Base LX - 512 m (Multimode Fiber) • 1000 Base LX - 20 Km (Singlemode Fiber) • 1000 Base LH - 80 Km (Singlemode Fiber)
LAN Technologies 10 Gig Ethernet • 10 Gbps bandwidth. • Uses same CSMA/CD media access protocol as in Ethernet. • Propositioned for Metro-Ethernet • Maximum Segment Length • 1000 Base-T - Not available • 10GBase-LR - 10 Km (Singlemode Fiber) • 10GBase-ER - 40 Km (Singlemode Fiber)