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Non-Ethernet Networks. Chapter 7. Contents. Define the characteristics, cabling, and connectors used in Token Ring Describe the characteristics, cabling, and connectors used in ARCnet and LocalTalk Explain the characteristics, cabling, and connectors used in FDDI and ATM. Introduction.
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Non-Ethernet Networks Chapter 7
Contents • Define the characteristics, cabling, and connectors used in Token Ring • Describe the characteristics, cabling, and connectors used in ARCnet and LocalTalk • Explain the characteristics, cabling, and connectors used in FDDI and ATM
Introduction • Ethernet monopolizes today’s networks with an 80-90% share • Other technologies such as those introduced in this chapter are fading • Network+ expects you to understand them
Token Ring • Token Ring is also called IEEE 802.5 • Supports 16 Mbps compared to 10 Mbps for 10BaseT Ethernet • 100 and 1000 Mbps Token Ring standards exist • Uses a physical star topology • Uses a logical ring topology
Logical Ring Topology • Token Ring nodes communicate directly only with the upstream and downstreamneighbors
Token Passing • A token passing system controls access to the ring • Nodes may only transmit when they receive the token • Only one node may transmit at a time • All nodes check packets for their MAC address • The destination node acknowledges receipt of the packet by sending a packet back to the sender • Then the sender releases a new free token
Token Passing • After receiving a token, a Token Ring node with data to send creates a new packet and sends it to its downstream neighbor • A station must wait for the token before it can send data • Access to the wire is predictable rather than random – called deterministic
Token Ring Packet • Token Ring packets include the source MAC address, destination MAC address, the data to be transmitted, and a Frame Check Sequence (FCS) to check for errors
Token Ring Speed • Token Ring runs at 4 Mbps or 16 Mbps • Newer versions run faster but Network+ does not include them • Bandwidth is used more efficiently than with Ethernet since there are no collisions • The slowest device on the ring determines the speed of the ring
Priorities • Some systems may be configured for a higher priority • Access to the token is more often • Rarely used
Physical Star Topology • A physical ring topology cannot function if the ring breaks
Logical Ring Topology • Token Ring uses a physical star topology and logical ring topology • The ring is hidden inside the hub, called a Multistation Access Unit (MAU or MSAU) • Nodes connect to the hub with UTP or shielded twisted pair (STP)
Shielded Twisted Pair • Original Token Ring networks used shielded twisted pair (STP) • Two pairs of copper wires surrounded by a metal shield to prevent electrical interference • Up to 260 computers • Distance from hub to computer may not exceed 100 meters
Connectors • Token Ring uses a Type 1 connector for STP • These hermaphroditic (neither male nor female) are called IBM-type Data Connectors (IDC) or Universal Data Connectors (UDC) – plug into each other • Token Ring cards use a 9-pin female connector
Token Ring over UTP • Token Ring over UTP uses the same UTP cable and RJ-45 connectors as Ethernet • Uses two pairs: 3-6 and 4-5 • UTP is much cheaper than STP • Supports up to 72 nodes within 45 meters of the MAU
Connecting MAUs • Extending a Token Ring network requires extending the ring topology • MAUs have special ports call Ring In and Ring Out to extend the ring • Ring Out connects to Ring In
Connecting MAUs • When linked together properly, MAUs form a single logical ring • Up to 33 MAUs may be connected
Token Ring More efficient use of bandwidth Guarantees every node gets some bandwidth Appears to be a dying technology Ethernet Less expensive Simpler devices Much larger installed base leading to cheaper equipment Token Ring vs. Ethernet
ARCnet • Attached Resource Computer Network (ARCnet) was invented by Datapoint Corporation • Both a physical and logical star topology • Uses token passing • Used RG-62 coaxial cable initially and later UTP • 2.5 Mbps (ARCnet Plus ran at 20 Mbps)
ARCnet Hubs • 8 or 16 port ARCnet hubs may be daisy-chained or strung together to support additional nodes • Segment lengths up to 600 meters • ARCnet now supports UTP and fiber optic cabling • Popular in robotics and industrial controls but not computer networks
LocalTalk • Created by Apple • Bus topology • Proprietary cabling using round DIN-style connectors
FDDI • Fiber Distributed Data Interface (FDDI) was developed by the American National Standards Institute (ANSI) • High speed, highly redundant technology designed for high-speed backbones • Uses a dual token passing ring • Each ring runs at 100 Mbps with an aggregate speed of 200 Mbps
FDDI Topology • Uses a true physical ring or a physical star topology
FDDI Connectors • FDDI connectors are unique • Later versions use CAT 5 UTP (CDDI) and copper instead of fiber • FDDI segments can be two kilometers between stations with a maximum ring size of 100 kilometers
ATM • Asynchronous Transfer Mode (ATM) runs at 155 Mbps using fiber optic cabling or CAT 5 UTP • Physical star topology • Two fiber connectors per node • CAT 5 or better cabling with RJ-45 connectors • ATM uses fixed-length packets on a point-to-point connection and is popular for WAN connections