BCMSN30S06L05 实施WLAN.ppt
Wireless LANs,Implementing WLANs,Cisco WLAN Implementation,Autonomous WLAN solutionAutonomous access pointsLightweight WLAN solutionLightweight access pointsWLAN controller,Autonomous WLAN Solution,Autonomous access pointCisco IOS softwareNetwork infratructurePoE switch and routerWireless Domain Services(WDS)Management supportWireless LAN Solution Engine(WLSE)Centralized managementAcess Control Server(ACS)RADIUS/TACACS+security,Lightweight WLAN Solution,Lightweight access pointNetwork infratructurePoE switch and routerCisco Wireless LAN controller(WLC)Access point configurationCisco Wireless Control System(WCS)ManagementLocation applianceLocation trackingCisco Secure Acess Control Server(ACS)RADIUS/TACACS+security,Lightweight WLAN Solution,Lightweight Access Point Protocol,Real-time frame exchange and certain real-time portions of MAC management are accomplished within the access point.Authentication,security management,and mobility are handled by WLAN controllers.Data and control messages are exchanged between the access point and the WLAN controller using LWAPP.Control messages are encrypted.All client data traffic is sent via the WLAN controller.,LWAPP,Layer 2 modeLayer 2 LWAPP is in an Ethernet frame.The WLAN controller and the access point must be in the same broadcast domain and IP subnet.Layer 3 modeLayer 3 LWAPP is in a UDP/IP frame.The WLAN controller and access point can be in the same or different broadcast domains and IP subnets.The access point must obtain an IP address via DHCP.,Association of Access Point to WLAN Controller,Access points use LWAPP in Layer 2 and Layer 3 mode to associate to the WLAN controller.In Layer 3 mode,the access point sends an LWAPP discovery request to the controller management IP address via a directed broadcast.The controller responds with a discovery response from the manager IP address that includes the number of access points currently associated to the access point manager interface.The access point chooses the access point manager IP address with the least number of access points and sends the join request.All subsequent communication is to the WLAN controller access point manager IP address.,Cisco Aironet WLCs,Scalability Integrated Radio Resource Management(RRM)Zero-configuration deploymentMultilayered securityIntrusion detection,location,and containmentMobility managementReliability Intuitive management interfaces,WLC 2000,WLC 4400,Comparison of the WLAN Configuration,Autonomous WLAN solutionAutonomous access pointsConfiguration of each access pointIndependent operationCentralized management via WLSEAccess point redundancy,Lightweight WLAN solutionLightweight access pointsConfiguration via WLCDependent on WLCCentralized management via WCS WLC redundancy,WLAN Components,Cisco Unified Wireless Network,Cisco Unified Wireless Network(Cont.),FeaturesIndustrys best range and throughputEnterprise-class securityMany configuration optionsSimultaneous air monitoring and traffic deliveryWide area networking for outdoor areas,BenefitsZero-touch managementNo dedicated air monitorsSupport for all deployment scenarios(indoor and outdoor)Secure coverage to advanced services,Mobility Platform,Cisco Aironet Access Points and Bridges,Indoor Access Points,1130AG,1000,Indoor Rugged Access Points,1500,1240AG,1230AG,Outdoor Access Points/Bridges,1400,1300,Power over Ethernet,2005 Cisco Systems,Inc.All rights reserved.,Power over Ethernet(PoE),Sending operating power over Ethernet Category 5 cable Power-sourcing equipment(PSE)Switches,power injectorPowered devices Access points,IP phonesUp to 15.4W power per portDistances up to 100 metersAlternative:AC power adapter,PoE Delivery,Pair 1,2 and 3,6,Pair 4,5 and 7,8,Two approved methods for“inserting”power into Ethernet cable:,Detection of power requirementsIEEE 802.3afCisco proprietary inline power,Midspan Power Injection,Uses pairs 4,5 and 7,8Requires eight-wire cablingDoes not extend 100-m total length limitNot possible for 1000TX,Power-Sourcing Equipment,Power injectorAIR-PWRINJ3/AIR-PWRINJ-FIBPowering switchCisco Catalyst 3560-PS/3750-PSCisco Express CE500-LC/CE500-PCCisco Catalyst 4500/6500 switch with inline power line cardsRouter module NM-16ESW-PWR Router card HWIC-4ESW-POERouter with PoE support,Investment Protection,Cisco has shipped over 18 million ports with PoE installed.New Cisco devices(PSEs and powered devices)support both PoE methods.IEEE 802.3afCisco proprietary PoEExamples:Access points 1131AG,1242AGSwitches:3560,3750Router:1812,HWIC-4ESW-POEAutomatic detection;no configuration is required.,PoE Switch,switch(config-if)#power inline auto|never,Display PoE statistics,switch#show power inline interface,switch#show power inline Available:370.0(w)Used:61.6(w)Remaining:308.4(w)Interface Admin Oper Power Device Class Max(Watts)-Gi0/1 auto off 0.0 n/a n/a 15.4Gi0/2 auto on 15.4 Ieee PD 3 15.4Gi0/3 auto off 0.0 n/a n/a 15.4Gi0/4 auto on 15.4 Ieee PD 3 15.4Gi0/5 auto off 0.0 n/a n/a 15.4Gi0/6 auto on 15.4 Ieee PD 3 15.4Gi0/7 auto off 0.0 n/a n/a 15.4Gi0/8 auto on 15.4 Ieee PD 3 15.4,PoE configuration,PoE Switch Port Status,Antennas,2005 Cisco Systems,Inc.All rights reserved.,Antenna Concepts,DirectionalityOmnidirectional antennas(360 degree coverage)Directional antennas(limited range of coverage)GainMeasured in dBi(gain over theoretical isotropic)More gain means focusing in certain directions,limited range of coveragePolarizationVertical polarization for WLAN,Antenna Theory,A theoretical isotropic antenna has a perfect 360-degree vertical and horizontal beamwidth.Reference for all antennas.,Omnidirectional Antenna:Dipole,Energy lobes“pushed in”from the top and bottomHigher gainSmaller vertical beamwidthLarger horizontal lobeTypical dipole pattern,2-dBi Dipole Standard Rubber Duck,Directional Antenna,Lobes are pushed in a certain direction,causing the energy to be condensed in a particular area.Very little energy is in the back side of a directional antenna.,6.5-dBi Diversity Patch Wall Mount 55 degrees,Connectorized 5-GHz Antennas,Cisco 5-GHzRubber Antenna(Flat with Blue Dot),Cisco 2.4-GHzRubber Antenna(Round,No Dot),5-GHz(802.11a)antennas have blue ID markers.Dual-band(2.4-GHz and 5-GHz)antennas have yellow dots.,Cisco Access Point/Bridge Antennas,Multipath Distortion,Multipath distortion(a form of radio degradation)occurs when radio signals bounce off metal objects in a room,such as metal cabinets or ceiling lights.OFDM overcomes multipath distortion through parallel frequency use.,Multiple signals at receiver cause distortion of the signal.As radio waves bounce,they arrive at the receiver slightly delayed,combining with the original signal,causing distortion.Diversity systems use two antennas in different positions to reduce the degradation.,Definition of Decibel,Decibel(dB)Ratio of one value to anotherdBm=Power based on 1 milliwatt 0 dBm=1 mWdBi=Antenna gain based on isotropic antenna,Effective Isotropic Radiated Power,Transmit power is rated in dBm or mW.Power coming off an antenna is Effective Isotropic Radiated Power(EIRP).FCC and ETSI use EIRP for power limits in regulations for 2.4-GHz and 5-GHz WLANs.EIRP dBm=Power dBm cable_loss db+antenna_gain dBi,Antenna Cable Loss,Use cable that is supplied with the antenna,avoiding long cable runs when possible.Cisco offers these cables:LMR400-style cables20 and 50 feetTotal loss of 1.3 and 3.4 dB,respectively LMR600-style cables100 and 150 feetTotal loss of 4.4 and 6.6 dB,respectively,LMR400,LMR600,Point-to-multipointFCC allows increasing the gain of an antenna/cable system if the transmitter power is reduced below 30 dBm in a 1:1 ratio.Reduce transmit power below maximum of 30 dBm by 1 dBm and increase antenna/cable system gain by 1-dBi.,2.4-GHz EIRP Rules for FCC-Governed Areas,Point-to-Multipoint,The above values reflect the 1:1 rule.,Currently ETSI allows a maximum of 20 dBm EIRP on point-to-multipoint and point-to-point installations17 dBm maximum transmitter power with 3 dBi in gain attributed to antenna and cable combination.Reduce transmit power below maximum of 17 dBm by 1 dBm and increase antenna/cable system gain by 1 dBi.,2.4-GHz EIRP Rules for ETSI-Governed Areas,EIRP Rules:Summary,5.725 MHz and above currently not allowed in most of Europe,Summary,Autonomous and lightweight WLAN solutions are the Cisco implementations of WLAN.LWAPP is the protocol used between lightweight access points and WLAN controllers.WLAN components include clients,access points,controllers,management systems,infrastructure devices,and security server.The Cisco Unified Wireless Network provides a unified enterprise-class wireless solution.Cisco Aironet access points are available for indoor or outdoor use.Access points and IP phones can be powered over Ethernet cable.Characteristics of antennas are directionality,gain,and polarisation.Multipath distortion can cause low quality data transmission.Antenna and RF power is measured in decibels.EIRP limits are defined by FCC and ETSI regulations.,
