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Universal Power Over Ethernet - World’s First Power-Extended Network Rev 6 UABU Engineering 12/1/2010 © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 1 • Power over Ethernet basics • Universal Power Over Ethernet (UPOE) • LLDP based UPOE • Forced 4-pair UPOE © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2 Power Over Ethernet Basics © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 3 GLOSSARY: PoE – Power Over Ethernet DTE – Data Terminal Equipment PSE – Power Sourcing Equipment (eg: CAt4K Switch) PD – Powered Devices (end device receiving power) LLDP – Link Layer Discovery Protocol (Layer 2 protocol) ALT-A : IEEE Terminology for Signal pair – (1,2) & (3,6) on a RJ45 pinout ALT-B : IEEE Terminology for Spare pair – (4,5) & (7,8) on a RJ45 pinout © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4 Power over Ethernet (PoE) Delivers DC Power and data over a Standard Copper Ethernet Cable(RJ45) Power Sourcing Equipment PSE Ethernet Cable Powered Device IP-Phone PD Source: Fred Schindler, PoE Nerd lunch presentation © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 5 • PoE/PoE+ is intended for DTE powering – to provide a 10Base-T, 100Base-T or 1000Base-T device with a single interface to both data it requires and power to process this data. • PoE : IEEE 802.3af – Delivery of upto 15W of power over ALT A pairs of RJ45 • PoE+ : IEEE 802.3at –Delivery of upto 30W of power over ALT A pairs of RJ45 © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 6 • Figure 1 below shows the normal Data transmission between two PHY silicon. • Figure 2 depicts how power is inserted along with data on ALT-A or ALT-B pairs to provide DTE powering. A power source introduces a port voltage “V” through the center tap of the Ethernet transformer. The end device in need of power, connects its load to the center tap of the Ethernet transformer to draw power from the source voltage “V”. This power does not affect the data since it is fed as a common-mode voltage. Fig 1.Ethernet Data Transmission over RJ45 © 2010 Cisco and/or its affiliates. All rights reserved. Fig 2. Overlaying Power with Data Cisco Confidential 7 • Power is coupled from PSE to PD through a center tap transformer configuration • Power is extracted on the PD side from center • The diode bridge is to ensure PD is polarity PD chip tap again and fed to a diode bridge 50-57V insensitive (see next slide). • The diode bridge in turn feeds a PD chip which takes care of implementing the PD features. • This configuration can provide upto 30W • To double the power, the unused ALT B pairs (shown in the picture) are put to use as well. Simply by duplicating the circuitry shown on unused pairs upto 60W can be drawn. © 2010 Cisco and/or its affiliates. All rights reserved. Source: Fred Schindler, PoE Nerd lunch presentation Cisco Confidential 8 AC + + + AC + Source: Fred Schindler, PoE Nerd lunch presentation © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9 • Detection—is this a true PD device? • Physical Layer Classification—how much power is required? (PoE - Type I) • Power-on—provide the requested power (upto 12.95W is available at the PD). • Data Link Layer Classification (LLDP) —refine the required power(more than 15.4W request and upto 30W – Poe+ - Type II). Source: Fred Schindler, PoE Nerd lunch presentation © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10 DETECTION: • Send Detection voltage pulse, measure current, Calculate Rdet = (V1-V2)/(I1-I2) Vport Detection Classification Power-On • Valid Detection Signature? – Yes (IEEE802.3af/at define the valid and invalid ranges) CLASSIFICATION: • Send Classification Voltage pulse, measure current (Physical layer classification) • Valid Classification signature? – Yes (IEEE802.3af/at define the valid and invalid ranges) Time POWER ON: • Turn on power © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11 • • • • IEEE 802.3at defines all the parameters related to power on, power monitoring and related timing etc for PoE/PoE+ This is to ensure safety and proper operation for a PoE powered network The table below shows some key parameters. Ie Inrush control and Power on time Refer to IEEE802.3at for a detailed list and explanation Parameter Unit Power turn on time ms Inrush current(startup mode) mA 400 450 Inrush time ms 50 75 © 2010 Cisco and/or its affiliates. All rights reserved. Min max 400 Cisco Confidential 12 Upper limit due to: - component limits - safety Short Circuit limit -PSE protection PD Surge Allowance (~15%) Lower limit: - supports the maximum average PD demand © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13 • DC Disconnect - Decided based on maintain power signature -If PD current draw is in the range of Imin for greater than TMPDO -After power removal – PSE goes back to start of state machine (detection state) Parameter Symbol Unit Min Max IDLE state current Imin mA 0 5 PD maintain power signature dropout time Tmpdo ms 300 400 © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 Universal Power Over Ethernet © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15 © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16 PDChip • Replicate the same ALT-A HW circuitry on the unused 50-57V ALT B pairs • Upto 60W delivery using all the 4-pairs on cat5e • Even under worst case (100m cable) 51W available at PD PDChip • Cisco’s proprietary UPOE defines two power up mechanisms LLDP based (preferred) Forced 4-pair © 2010 Cisco and/or its affiliates. All rights reserved. 50-57V Cisco Confidential 17 LLDP based UPOE © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 18 • LLDP – Link Layer Discovery Protocol LLDP is a layer 2 protocol in Networking. It is vendor-neutral and used for advertising identity, capabilities and neighbours on a LAN LLDP uses Type, Length and Value fields(TLV) to convey the information © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 19 • IEEE 802.3at already defines LLDP for power negotiation greater than 15.4W and upto 30W. UPOE uses the same negotiation method to provide upto 60W contingent on a successful 4-pair handshake. IEEE802.3at LLDP format is shown below. • “4-wire Power Via MDI” - is the new subtype for Cisco specific OUI TLV. It is present in all modes of operation and is used to exchange 4-pair capabilities before enabling 4pair and providing upto 60W. © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 20 TLV type TLV information String Length 7 bits 9bits TLV type-127(organisation specific) Information string length = 5 (bytes) Cisco OUI Identifier = 00-01-42 Cisco OUI subtype = 1 Bit Cisco OUI Identifier 3 octets Cisco OUI subtype PSE/PD capabilities 1 octet Function Value/Meaning 0 UPOE supported 0=No 1=Yes 1 ALT-B pair Detection/Classification Required 0=No 1=Yes 2 PD ALT-B pair desired state 0=No 1=Yes 3 PSE ALT-B pair operational state 0=Disabled 1=Enabled 4:7 Reserved © 2010 Cisco and/or its affiliates. All rights reserved. 1 octet Cisco Confidential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his is an example for independent PD architecture – Actual handshake will depend on the PD architecture © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 22 Forced 4-pair UPOE © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 23 • To support already deployed devices which don’t have LLDP capabilities • Physical layer signature is a must on both ALT-A and ALT-B pairs. This is used in lieu of LLDP to detect UPOE end device. • Least Preferred – Doesn’t support the advantages that come with LLDP. • For instance, In LLDP if a UPOE port drops down in power consumption this extra power can now be returned to general pool for use by other ports. Forced 4-pair implementation doesn’t support this – power allocation to a forced 4-pair port is static at 60W • By Default UPOE switch uses LLDP – to turn on forced 4-pair a CLI command is provided => “power inline four-pair forced” © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 24 © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 25 © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 26 1 2 3 4 5 6 7 8 Diode Bridge Vout Input 50-57V PD chip(s) DC-DC Vout_rtn RJ45 Diode Bridge Data Path Power Path © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 27 • For Utilizing UPOE the end device should have the following A IEEE802.3at compliant Powered Device (PD) circuit (ALT-A and ALT-B pairs could combine before and feed into a single PD chip if LLDP capabilities are present; However if forced UPOE is needed then a compliant PD chip would be needed on both ALT-A and ALT-B pairs) LLDP implementation of Cisco 4-pair power via MDI TLV LLDP TLV for power negotiation • NOTE: In absence of LLDP forced 4-pair can be utilized but this method is not the preferred method of implemention. If LLDP implementation is possible the end device is advised to take that route. © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 28 Thank you. © 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 29