Tài liệu Application Overview Power-over-Ethernet docx

Introduction Final approval of the Power-over-Ethernet (PoE) standard in June 2003, removed a significant barrier to widespread adoption of IP telephony. The standard (IEEE 802.3af) specifies how to supply power to compliant devices over Ethernet LAN cabling. Armed with uninterruptible power supplies (UPS), IT staff can now deploy Voice over IP (VoIP) telephones without worrying about them not functioning during a power outage. The benefits of this enabling technology extend beyond IP telephony. Many applications that deploy equipment with low power requirements in areas that aren't already wired for power will benefit from reduced cabling costs. A single standard Ethernet cable will now be able to provide both power and communication services to wireless network access points, IP cameras, security badge readers, and many other devices. Advantages of PoE include: • Reduced cabling costs: One cable provides both power and data. • Reliability: A UPS at the power distribution source can guarantee power to all connected devices. • The first worldwide power standard: This means that PoE devices will plug in anywhere. • SNMP network management: This system can be used to monitor and control connected devices. • Simplification of wireless LAN installation: Access points can be moved and wired in easily. Application Overview Power-over-Ethernet WHITE PAPER Application Overview: Power-over-Ethernet Page 2 ADC Midspan Controller The ADC midspan controller is a rack-mounted, fully 802.3af compliant midspan PSE that can power between one and 24 PoE devices. It offers the flexibility of universal input power (115/230VAC, 50/60Hz) and multiple configurations. The midspan controller panel's powerful management features include: • Full compliance to the IEEE 802.3af standard with capability to provide 15.4 Watts of power on every port simultaneously • Redundant power capability on all designs • Modular SNMP and Power Supply chasis design, allowing in-service field upgrades to redundant power and/or SNMP capability • SNMP Stacking, allowing up to 5 chassis to be controlled b a single SNMP card and IP address • Dual complance to both IEEE 802.3af and Pre- Standard Cisco in-line powering When and How to use ADC's Solution When 1. An IEEE 802.3af powered device such as a VoIP phone, Wi-Fi access point, network camera, etc. requires power via the Ethernet cabling 2. Total distance between Ethernet switch and powered device is 100 meters or less 3. Ethernet switch is not PoE capable 4. Ethernet switch is PoE capable, but cannot deliver the required power How 1. Install the midspan PoE controller between the existing Ethernet switch and the powered device. ADC recommends installing the midspan PoE controller and Ethernet switch in the same or adjacent racks. 2. Install standard RJ45 patch cable between the existing Ethernet switch and the bottom port of midspan PoE controller. 3. Install standard RJ45 patch cable between the top port of midspan PoE controller and a standard horizontal distribution patch panel. 4. Use ANSI/TIA/EIA-568 standard methods to run horizontal cabling between the distribution patch panel and the wall outlet and jack in the work area. 5. Install a standard RJ45 patch cord between the wall outlet jack and the powered device at the work area. Installation The diagram above shows a typical installation with ADC's PoE solution. 10/100Base-T data is routed via a standard RJ45 cable from the Ethernet switch to the midspan PoE controller. The PoE controller injects power into the unused pairs if an 802.3af compliant device is detected on the remote end. The power plus data is routed from the PoE controller to a standard RJ45 patch panel for distribution to the work area. It is important to use appropriate cable management and installation practices to route these cables as critical voice and data traffic is being transmitted over the Ethernet cables. Ethernet Distribution Frame In Telecommunications Room (TR) Work Area (WA) IP desk phone Powered Device (PD) Power Required Workstation PoE Power Not Needed To Work Area (WA) without PoE Power-over-Ethernet Midspan Controller Horizontal Cross-Connect (HC) To PD in Work Area (WA) Requiring PoE Horizontal Cabling Application Overview: Power-over-Ethernet Page 3 Frequently Asked Questions Q: If I run Power-over-Ethernet to a computer, will I damage the NIC? A: No, ADC has designed the Power-over-Ethernet controller to sense if the remote powered device is IEEE 802.3af compliant. If the powered device is not designed to accept power, the controller will not send power. Q: What is PoE's distance limitation of power? A: Power-over-Ethernet is limited by the distance that standard Ethernet can run, which is 100 meters between Ethernet switch and powered device. IMPORTANT NOTE: The midspan PoE controller is passive to the Ethernet signal, and does not regenerate the signal. The distance limitation from the Ethernet switch to the powered device is 100 meters regardless of where the midspan PoE controller is located in the network. Q: Can I run 1000Base-T through the midspan PoE controller? A: No, the PoE controller is currently only designed to work with 10/100Base-T Ethernet. The IEEE 802.3af document only defines Power-over-Ethernet for 10/100Base-T and not for Gigabit Ethernet. Furthermore, all available powered devices are also 10/100Base-T. Q: I'm using a Cisco device that is line power capable, but was introduced before the IEEE 802.3af standard was released, can I power it with your midspan PoE controller? A: Yes, although certain Cisco devices such as the 7960 IP Phone and some Aironet Access Points use a Pre-Standard in-line powering scheme, ADC has designed all of our Midspan devices to detect both IEEE 802.3af and Pre-Standard Cisco devices and send the appropriate power, all from the same device, without any special installation gear, techniques, or configurations. Q: How much power is being run over the Ethernet cable, and is it safe? A: The IEEE 802.3af document defines five classifications of power depending on the device; ADC's solution covers this full range, which calls for a maximum of 15.4 Watts on each and every powered port. Accounting for the resistance in the cable, the powered device can draw up to 12.95 Watts of power at the remote end. Although this is potentially a lot of power, remember that the ADC design senses if the remote device will accept power, and if not, will not send any power. Q: Which pins on the RJ45 are powered? A: Midspan devices power on pins 4,5 and 7,8, the unused pairs in 10/100Base-T. This allows the data to pass through unaffected (i.e. if power is removed from the PoE chassis, the data is unaffected). Q: Can I manage the PoE Controller via software? A: Yes, ADC has an optional SNMP controller card that can be installed into our standard chassis. This allows you to manage and monitor the PoE controller. Our design also allows you to daisy-chain up to five PoE controllers together and manage them with one SNMP card and one IP address, simplifying the management and reducing the cost of the solution. Q: How can I find out if ADC's PoE controller will work with my VoIP phone or Wi-Fi access point? A: ADC's controller will work with any IEEE 802.3af compliant device as well as Pre-Standard Cisco in-line powered devices. Check the technical specifications of your device for IEEE 802.3af compliance. The IEEE specification has been released since June 2003, so most manufacturers are compliant. If you are unsure, please contact ADC's technical assistance center. We would be happy to assist you in determining the best solution for your needs. Q: Do I need to run new RJ45 cables from the midspan controller to the switch or to the powered device? A: No. The midspan controller uses existing cabling, since both the power and Ethernet signals are fed through the same cable. Q: How do I know if power is fed through the RJ45 cable? A: An LED on the front of the panel indicates whether or not the power is injected though the cable. Also, querying the CPU card both locally and remotely will provide you with the power status of each port. Web Site: www.adc.com From North America, Call Toll Free: 1-800-366-3891 • Outside of North America: +1-952-938-8080 Fax: +1-952-917-3237 • For a listing of ADC’s global sales office locations, please refer to our web site. ADC Telecommunications, Inc., P.O. Box 1101, Minneapolis, Minnesota USA 55440-1101 Specifications published here are current as of the date of publication of this document. Because we are continuously improving our products, ADC reserves the right to change specifications without prior notice. At any time, you may verify product specifications by contacting our headquarters office in Minneapolis. ADC Telecommunications, Inc. views its patent portfolio as an important corporate asset and vigorously enforces its patents. Products orfeatures contained herein may be covered by one or more U.S. or foreign patents. An Equal Opportunity Employer 102260AE 3/06 Revision © 2004, 2006 ADC Telecommunications, Inc. All Rights Reserved WHITE PAPER . points can be moved and wired in easily. Application Overview Power-over-Ethernet WHITE PAPER Application Overview: Power-over-Ethernet Page 2 ADC Midspan. PoE Power-over-Ethernet Midspan Controller Horizontal Cross-Connect (HC) To PD in Work Area (WA) Requiring PoE Horizontal Cabling Application Overview: Power-over-Ethernet Page