Content Campus Network Design Thana Hongsuwan Ethernet Standard Transparent Bridges LN Switches LN and Switch Operation Loop Resolution Virtual LNs, InterVLN Routing Router Redundancy Switch Security Campus Network Design 2003, Cisco Systems, Inc. ll rights reserved. 1-1 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-2 Scoring ว ธ การเร ยน Class ctivity 35 % ssignment 15 % Final 50 % Student Centered Learning ctive Learning Lab Configuration Quiz 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-3 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-4
LOH IBM 360 @ U of Hawaii Ship Island Ethernet History Two way Communication (ship or island to IBM Send on Enter Error Detection 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-5 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-6 MC techniques Ethernet and IEEE 802.3 Contention Medium is free for all node senses the free medium and occupies it Example: Ethernet, IEEE 802.3 Round robin Give every body a turn Inefficient for lightly loaded network Example: Token Ring/IEEE 802.5, Token Bus/IEEE 802.4, FDDI Reservation schedule a time slot like TDM Example: DQDB 1973: First LN Ethernet 2.94 Mbps (developed by Xerox Palo lto Research Center, including Bob Metcalfe (who later founded 3Com)) 1980: 10Mbps ethernet specification by DEC, Intel, and Xerox 1985: becomes IEEE 802.3 standard (already widely used before this time) 1995: 100Mbps Fast Ethernet standardized in IEEE 802.3u (already widely used before this time) 1998: 1Gbps Gigabit Ethernet IEEE standard issued 1999: 10Gbps ethernet under development 2002: 10GbE Standard issued 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-7 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-8
OSI Model and Project 802 Project 802 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-9 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-10 Medium ccess Control Medium ccess Control Logical Link Control (LLC) provides single data link control protocol for all IEEE LNs while Media ccess Control (MC) provides different protocols for different LNs. MC contains synchronization, flag, flow and error control specifications necessary to move information from one place to another and the physical address of the next station to reduce and route a packet. The role of Data Link layer is to permit the transfer of data between the stations and detect transmission errors. IEEE divides this layer into separated sub-layers : MC (Medium ccess Control) and LLC (Logical Link Layer) The MC sublayer control the access of medium using access method. The LLC provides interface to next upper layer. The data link layer protocol performs: perform functions related to medium access (MC sublayer) concerned with the transmission of a link-level between two nodes (LLC sublayer) Network Data Link Physical LLC MC Logical Link Control sublayer Medium ccess Control sublayer 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-11 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-12
Ethernet 10BSE5-THICK ETHETNRT Xerox (Bob Metcalfe) performed initial development of Ethernet in 1976 (2.94 Mbps,over 100 personal workstations,1-km long cable) and was later joined by the Digital Equipment Corporation (DEC) and Intel to define the Ethernet 1 specification in 1980. The same group subsequently released the Ethernet 2 specification in 1984. The Ethernet specification describes a packet switching CSM/CD LN. 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-13 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-14 Ethernet 10 Base-5 Ethernet 10 Base-5 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-15 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-16
Transceiver connection in 10Base5 Vampire Tap 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-17 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-18 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-19 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-20
10Base5 tap : cable does not need to be cut transceiver : send/receive, collision detection, electronics isolation UI : ttachment Unit Interface Use for backbone networks maximum segment length=500m maximum number of stations per segment=100 0.5 Coax vampire tap BNC connector transceiver UI cable minimum distance between two stations = 2.5 m maximum network distance between two stations = 2.5km NIC 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-21 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-22 10BSE2-THIN ETHERNET Ethernet 10 Base-2 LN Topology, reduced cost, easy installation. Shorter range, less capacity. 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-23 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-24
10Base2 Group Discussion BNC connector No drop cable use for office LN What is its benefit since length < 500m? maximum segment length=185m maximum number of stations per segment=30 0.25 Coax BNC T-connector NIC ให อภ ปรายความแตกต างของ 10 Base5 และ 10 Base2 ให ว เคราะห ว าในการใช งานจร ง ร ปแบบเคร อข ายแบบ 10 Base5 และ 10 Base2 น าจะเก ดป ญหาอะไรได บ อย minimum distance between two stations = 0.5 m maximum network distance between two stations = 925 m 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-25 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-26 StarLN Developed by by Tim Rock and Bill ranguren at T&T Information Systems as an experimental system in 1983. Used a star topology from a central hub. The standard known as 1BSE5 was adopted as 802.3e in 1986 The original StarLN ran at a speed of 1 Mbit/s. major design goal in StarLN was reduction in Ethernet installation costs by the reuse of existing telephone onpremises wiring and compatibility with analog and digital telephone signals in the same cable bundle. Used UTP (Unshielded Twisted Pair) Cat.3 1987, Synoptics introduce LTTISNET and delivered 10 MBps over telephone wire, also known 10 Base T 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-27 WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-28
1BSE5 Star topology 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-29 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-30 10 BSE-T Star topology LN, maximum length 100meters 10Base-T hub functions as a repeater UTP category 5 uses 2 pairs of wires terminated by an eight-bin (RJ-45 style) connector. This means that 4 pins of the 8-pin are used. The transmit and receive data signal on each pair of the segment are polarised, with one wire of the signal pair carrying the positive (+) signal and the other carrying the negative (-). Pin 1 2 3 4 5 6 7 8 Sig TD+ TD- RD+ U U RD- U U hub Medium Dependent Interface (MDI), RJ45 maximum segment length = 100m NIC 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-31 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-32
IEEE 802.5 (Token Ring): Ring Topology Token Ring Shared ring medium: all nodes see all frames Round Robin MC Protocol: determines which station can transmit special 3 byte pattern, the token, circulates around the ring perpetually and represents the "right to transmit" This establishes round robin media access Data flow is unidirectional ll data flows in a particular direction around the ring; nodes receive frames from their upstream neighbor and forward them to their downstream neighbor Data rate: 4 or 16 Mbps 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-33 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-34 Token Passing Token Passing 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-35 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-36
Token Passing Token Passing 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-37 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-38 IEEE 802.5 (Token Ring) using a Hub Group Discussion The star wired ring topology uses the physical layout of a star in conjunction with the token passing data transmission method. Data are sent around the star in a circular pattern. This hybrid topology benefits from the fault tolerance of the star topology and the reliability of token passing. ให อภ ปรายความแตกต างของ Ethernet และ Token Ring ให ว เคราะห ว าในการใช งาน ควรเล อก Ethernet และ Token Ring เพราะเหต ใด 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-39 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-40
LN characteristics Topology confined within geographical area relatively high data rate under single management LN Ingredients... Topology bus, star, ring hub hub hub stations stations stations Topology defines how nodes/stations are connected (structure of logical layout) 3 main LN typical topology : bus/tree : all nodes connected to a common medium star : all nodes are joined to a central nodes ring : nodes form a ring by point-to-point links to adjacent neighbors Transmission medium twisted pair, coaxial, fiber optics, wireless Medium access techniques protocol to coordinate the sharing of media router hub server bus star ring 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-41 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-42 Topology : Bus Topology : Ring B C D D B and C pplication Presentation Session Transport Network Data Link Physical D pplication Presentation Session Transport Network Data Link Physical node functions as a repeater only destination copies frame to it, all other nodes have to discarded the frame Unidirectional link C C B transmits frame addressed to B B C C C ignores frame B B copies frame C absorbs returning frame 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-43 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-44
Topology : Star Overview of LN Standard Each station attaches to the central node Two point-to-point links for transmitting and receiving Two alternatives operation: broadcasting and switching Easy to manage with relative low cost. But very vulnerable, since it depends entirely upon the operation of the central node. B C C transmits frame addressed to B C B C shared hub broadcasts packet to every ports but only destination copies frame switch hub retransmits packet to the destination only 802.2 802.3 802.4 802.5 Logical Link Control CSM/CD (Ethernet) Token Bus (Bus topology with logical ring) Token Ring (it followed Ethernet and is now widely used in the large number of IBM networks) 802.6 Distributed Queue Dual BUS --MN standard FDDI Fiber Distributed Data Interface (also using token) 802.3 CSM/CD 802.4 Token Bus 802.2 LLC 802.5 Token Ring 802.6 DQDB FDDI 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-45 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-46 IEEE 802.3 Specification Various standard defined for IEEE802.3 with a concise notation: 10Base5 -- thickwire coaxial, 500m 10Base2 -- thinwire coaxial or cheapernet, 185m 10BaseT -- twisted pair (most widely used today, 100m) 10BaseF -- fiber optics 10Broad36 -- broadband (only 802.3 standard 1/2 coax, 1800m) Fast Ethernet 100BaseTX, 100BaseT4, 100BaseFX, 100VG-nyLN(802.12) GigaEthernet 1000 Mbps (802.3z) available on fiber and on coax, UTP IsoEthernet (Category 3, 10Mbps Ethernet and 6.144Mb 96 channels ISDN) 10 Base 5 data rate in Mbps signaling baseband or broadband maximum segment length in hundreds of meters 2003, Cisco Systems, Inc. ll rights reserved. BCMSN v2.0 1-47