Presentation on theme: "Top-Down Network Design Chapter Ten Selecting Technologies and Devices for Campus Networks Copyright 2010 Cisco Press & Priscilla Oppenheimer."— Presentation transcript:
1 Top-Down Network Design Chapter Ten Selecting Technologies and Devices for Campus Networks Copyright 2010 Cisco Press & Priscilla Oppenheimer
2 Selecting Technologies and Devices We now know what the network will look like.We also know what capabilities the network will need.We are now ready to start picking out technologies and devices.Chapter 10 has guidelines for campus networks.
3 Campus Network Design Steps Develop a cabling plant designSelect the types of cablingSelect the data-link-layer technologiesSelect internetworking devicesMeet with vendors
4 Cabling Plant Design Considerations Campus and building cabling topologiesThe types and lengths of cables between buildingsWithin buildingsThe location of telecommunications closets and cross-connect roomsThe types and lengths of cables for vertical cabling between floorsThe types and lengths of cables for horizontal cabling within floorsThe types and lengths of cables for work-area cabling going from telecommunications closets to workstations
5 Centralized Versus Distributed Cabling Topologies A centralized cabling scheme terminates most or all of the cable runs in one area of the design environment. A star topology is an example of a centralized system.A distributed cabling scheme terminates cable runs throughout the design environment. Ring, bus, and tree topologies are examples of distributed systems.
6 Centralized Campus Cabling Building BBuilding CBuilding DBuilding ACable Bundle
7 Distributed Campus Cabling Building ABuilding BBuilding CBuilding D
8 Types of Media Used in Campus Networks Copper mediaOptical mediaWireless media
9 Copper Media Advantages Conducts electric current wellDoes not rustCan be drawn into thin wiresEasy to shapeHard to break
11 Coaxial Cable Solid copper conductor, surrounded by: Flexible plastic insulationBraided copper shieldingOuter jacketCan be run without as many boosts from repeaters, for longer distances between network nodes, than either STP or UTP cableNonetheless, it’s no longer widely used
12 Twisted-Pair CablingA “twisted pair” consists of two copper conductors twisted togetherEach conductor has plastic insulationShielded Twisted Pair (STP)Has metal foil or braided-mesh covering that encases each pairUnshielded Twisted Pair (UTP)No metal foil or braided-mesh covering around pairs, so it’s less expensive
13 UTP Categories Category 1. Used for voice communication Category 2. Used for voice and data, up to 4 MbpsCategory 3. Used for data, up to 10 MbpsRequired to have at least 3 twists per footStandard cable for most telephone systemsAlso used in 10-Mbps Ethernet (10Base-T Ethernet)Category 4. Used for data, up to 16 MbpsMust also have at least 3 twists per foot as well as other featuresCategory 5. Used for data, up to 100 MbpsMust have 3 twists per inch!Category 5e. Used in Gigabit EthernetCategory 6. Used in Gigabit Ethernet and future technologies
15 Copper Vs Fiber-Optic Cabling Twisted-pair and coax cable transmit network signals in the form of currentFiber-optic cable transmits network signals in the form of lightFiber-optic cable is made of glassNot susceptible to electromagnetic or radio frequency interferenceNot as susceptible to attenuation, which means longer cables are possibleSupports very high bandwidth (10 Gbps or greater)For long distances, fiber costs less than copper
16 Multimode Single-mode Larger core diameterBeams of light bounce off cladding in multiple waysUsually uses LED sourceLess expensiveShorter distancesSmaller core diameterLess bouncing around; single, focused beam of lightUsually uses LASER sourceMore expensiveVery long distances
17 Wireless Media IEEE 802.11a, b, g, n Laser Microwave Cellular Satellite
18 Cabling Guidelines At the access layer use Copper UTP rated for Category 5 or 5e, unless there is a good reason not toTo future proof the networkUse 5e instead of 5Install UTP Category 6 rated cable and terminate the cable with Cat 5 or 5e connectorsThen only the connectors need to be changed to move up in speedIn special casesUse MMF for bandwidth intensive applicationsOr install fiber along with the copper
19 Cabling Guidelines At the distribution layer use MMF if distance allowsSMF otherwiseUnless unusual circumstances occur and cable cannot be run, then use a wireless methodTo future proof the networkRun both MMF and SMF
20 LAN Technologies Half-duplex Ethernet (becoming obsolete) Full-duplex Ethernet10-Mbps Ethernet (becoming obsolete)100-Mbps Ethernet1000-Mbps (1-Gbps or Gigabit) Ethernet10-Gbps EthernetMetro EthernetLong Range Ethernet (LRE)Cisco’s EtherChannelThese days, use at least 100-Mbps Ethernet to the desktop and 100-Mbps, Gigabit, or 10-Gbps Ethernet in backbones. Also, use full-duplex Ethernet whenever possible.
21 IEEE 802.3 10-Mbps Ethernet 10 Mbps Ethernet 10Base5 10BaseT 10BaseF 2 pairs Category-3 or better UTP meters2 multimode optical fibersThick coax cable meters10Base210Broad36Thin coax cable meters3 channels of a private CATV system meters
24 IEEE 802.3 10-Gbps Ethernet 10GBase with Fiber Cabling 10GBaseLX4 10GBaseSR10GBaseLR10GBaseERMultimode or single-mode optical fibers300 meters multimode, km single-modeMultimode optical fibers metersSingle-mode optical fibers 10 kmSingle-mode optical fibers 40 km
25 IEEE 802.3 10-Gbps Ethernet 10GBase with Copper Cabling SFP+ Direct Attach10GBaseCX410GBaseTXAUI 4-lane PCS15 metersTwinax10 metersUTP or STP100 meters
26 Metro EthernetService offered by providers and carriers that traditionally had only classic WAN offeringsThe customer can use a standard Ethernet interface to reach a MAN or WANThe customer can add bandwidth as needed with a simple configuration change
27 Long-Reach EthernetEnables the use of Ethernet over existing, unconditioned, voice-grade copper twisted-pair cablingUsed to connect buildings and rooms within buildingsRural areasOld cities where upgrading cabling is impracticalMulti-unit structures such as hotels, apartment complexes, business complexes, and government agencies
28 Cisco’s EtherChannel Data Center Switch 800 Mbps EtherChannel West Fiber Run400 MbpsEast Fiber Run400 MbpsWiring Closet Switch
29 Internetworking Devices for Campus Networks SwitchesRoutersWireless access pointsWireless bridges
30 Selection Criteria for Internetworking Devices The number of portsProcessing speedThe amount of memoryLatency when device relays dataThroughput when device relays dataLAN and WAN technologies supportedMedia supported
31 More Selection Criteria for Internetworking Devices CostEase of configuration and managementMTBF and MTTRSupport for hot-swappable componentsSupport for redundant power suppliesQuality of technical support, documentation, and trainingEtc.
32 SummaryOnce the logical design is completed, the physical design can startA major task during physical design is selecting technologies and devices for campus networksMediaData-link layer technologyInternetworking devicesAlso, at this point, the logical topology design can be developed further by specifying cabling topologies
33 Review QuestionsWhat are three fundamental media types used in campus networks?What selection criteria can you use to select an Ethernet variety for your design customer?What selection criteria can you use when purchasing internetworking devices for your design customer?Some people think Metro Ethernet will replace traditional WANs. Do you agree or disagree and why?