• Gli standard 802.3af, 802.3at e gli sviluppi futuri. • Come disegnare l’impianto per integrare correttamente il PoE? (Cablaggio, budget PoE, ….) • Le soluzioni Netgear con supporto PoE

1. Come la tecnologia Power
over Ethernet può aiutare nello
sviluppo e disegno delle reti?
Webinar, 22/11/18, ore 15:00
Andrea Rossi
Senior System Engineer

2. o Gli standard 802.3af, 802.3at e gli sviluppi futuri.
Collegare un dispositivo non PoE ad una porta PoE dello switch,
può danneggiare il dispositivo? ….
o Come disegnare l’impianto per integrare
correttamente il PoE? (Cablaggio, budget PoE, ….)
o Le soluzioni Netgear con supporto PoE

3. Power Over Ethernet not …

4. What is PoE?
PoE is “Power over Ethernet”. PoE allows devices that require
power (PD) and supply power (PSE) to be supported over existing
switching infrastructure using at least a Cat5 cabling.
The maximum allowed continuous output power per cable is:
15.40 W for IEEE 802.3af
30 W for IEEE 802.3at

5. What is a PoE PSE device?
Power sourcing equipment (PSE) is a device such as a switch that provides
("sources") power on the Ethernet cable.
What is a PoE PD device?
A powered device (PD) is a device powered by a PSE and thus consumes
energy. Examples include wireless access points, IP Phones, and IP Cameras.
Many powered devices have an auxiliary power connector for an optional,
external, power supply.
What is PoE?

6. PoE standard 802.3af - 2003
IEEE802.3af (15.4W/port), approved in 2003 for PDs up to 12.95W (350mA) at 48V DC
PoE requires handshake before applying power
Power Sourcing Equipment (PSE) transmits power over 2 pairs (4 of 8 wires) on Cat5/5e/6 cable
Connect/disconnect protocol for applying/disconnecting power
• Detect device that needs power
• Determines power needed
• When to turn on power
• Detect device disconnect (AC and DC disconnect)
• When to remove power
Physical layer mechanism for PSE’s to characterize power demands of individual PD’s and thus
manage power delivered per port.

7. PoE standard 802.3at - 2009
The 802.3af POE standard is fine for network devices that require up to 13W.
Before 2009, high-power POE systems have been proprietary and not compatible with 802.3af POE.
New standard was introduced by the IEEE to increase the available power: 802.3at, or POE Plus.
Increased electrical power POE Plus nearly doubles the amount of electrical power available to powered devices, to 25.5 watts.
Compatible 802.3af POE Plus switches and injectors will recognise 802.3af powered devices and enable POE to them.
POE Plus powered devices can also be connected to 802.3af POE switches or injectors, and are
supposed to restrict how much power they use accordingly.
Smart power budgeting 802.3at includes scope for power sources and powered devices to communicate with each other
to negotiate an allowance of electrical power.
Note that 802.3at exists alongside the 802.3af standard; it does not replace it. 802.3af will still be employed by
the majority of Power over Ethernet devices or the foreseeable future.

8. Signature detection uses a lower voltage to detect a characteristic signature of IEEE-compatible PDs.
Classification follows the signature detection stage. If a PD displays a classification signature, it lets the
PSE know how much power it requires to operate
If a PD does not display a signature, it is class 0 and must be allocated the maximum 12.95 watts.
POE Plus equipment has a power class of 4. If a regular 802.3af POE source detects this class it will
simply enable power as if it was a class 0 device.
However, an 802.3at PSE will not only recognise the PD as a POE Plus device, it will also repeat the
classification stage, as a signal to the PD that is connected to a power source with full POE Plus power
available. POE Plus PSEs can supply up to 30 watts and available device power is 25.5 watts.
The power negotiation between a PSE and a PD can be implemented at the physical layer or at the
data link layer.
After the link is powered at the physical layer, the PSE can use LLDP to repeatedly query the PD to
discover the power needs of the PD. The data link layer allows finer control of power allotment.
Using LLDP is optional for the PSE but mandatory for a PoE+ PD that requires more than 12.95 watts
of power.
Detection & Classification

9. Passive PoE usually refers to any device using PoE that is not
802.3af or 802.3at.
Passive PoE does not perform a handshake, so it is extremely
important to know what PoE voltage your device requires before
plugging in the Ethernet cable and powering it up.
If you connect the wrong voltage you may cause permanent electrical
damage to the device.
Passive PoE

10. Property
802.3af (802.3at
Type 1) "PoE"
802.3at Type
2 "PoE+"
802.3bt Type
3 "4PPoE"
802.3bt Type 4
Power available at PD 12.95 W 25.50 W 51 W 71 W
Maximum power delivered by
PSE
15.40 W 30.0 W 60 W 100 W
Voltage range (at PSE) 44.0–57.0 V 50.0–57.0 V 50.0–57.0 V 52.0–57.0 V
Voltage range (at PD) 37.0–57.0 V 42.5–57.0 V 42.5–57.0 V 41.1–57.0 V
Maximum current Imax 350 mA 600 mA 600 mA per pair 960 mA per pair
Maximum cable resistance
per pairset
20 Ω[
12.5 Ω 12.5 Ω 12.5 Ω
Power management
Three power class levels
negotiated by signature
Four power class levels
negotiated by signature
or 0.1 W steps
negotiated by LLDP
Three power class
levels negotiated by
signature or 0.1
W steps negotiated by
LLDP
0.1 W steps
negotiated by LLDP
Derating of maximum cable
ambient operating
temperature
None
5 °C (9 °F) with one
mode (two pairs) active
10 °C (20 °F) with
more than half of
bundled cables pairs
at Imax
10 °C (20 °F) with
temperature planning
required
Supported cabling
Category 3 and Category
5
Category 5 Category 5 Category 5
Supported modes
Mode A (endspan), Mode
B (midspan)
Mode A, Mode B
Mode A, Mode B, 4-
pair mode
4-pair mode
Comparison of PoE parameters

11. Class Usage
Classification
current
Power range at
PD per pair
Power from
PSE per pair Class description
[mA] [W] [W]
0 Default 0–4 0.44–12.94 15.4
Classification
unimplemented
1 Optional 9–12 0.44–3.84 4.00 Very Low power
2 Optional 17–20 3.84–6.49 7.00 Low power
3 Optional 26–30 6.49–12.95 15.4 Mid power
4
Valid for Type 2
(802.3at)
devices,not
allowed for
802.3af devices
36–44 12.95–25.50 30 High power
5
Valid for Type 3
(802.3bt)
devices
40 (2×35.6 @4-
pair)
45
6 51 60
7 Valid for Type 4
(802.3bt)
devices
62 (4-pair) 75
8 71.3 (4-pair) 99
8+ 99.9 (4-pair)
Power levels available

12. PoE devices

13. o Gli standard 802.3af, 802.3at e gli sviluppi futuri.
Collegare un dispositivo non PoE ad una porta PoE dello switch,
può danneggiare il dispositivo? ….
o Come disegnare l’impianto per integrare
correttamente il PoE? (Cablaggio, budget PoE, ….)
o Le soluzioni Netgear con supporto PoE

14. PoE Applications: Wireless LAN
ProSAFE
Desktop
Tablet
ReadyNAS
Internet
Firewall
Modem
11AC Wireless Access
Point
Surveillance
PoE
VoIP
Phone
Server
Printer
Wireless LAN: Placement of Access Points
is key to delivering an effective wireless
network. PoE supported APs can be placed
in strategic locations – such as ceilings – out
of reach of electrical AC outlets.
Deployments can save on installation costs
when PoE capable switches are leveraged.
Note:
New Wireless APs (Dual Band IEEE802.11AC
wave2) will require PoE+ (802.3at) that
supports up to 25W per port

15. PoE Applications: VoIP
ProSAFE
Desktop
Tablet
ReadyNAS
Internet
Firewall
Modem
11AC Wireless Access
Point
Surveillance
PoE
VoIP
Phone
Server
Printer
Voice over IP phones: (VOIP) allow the
delivery of phone signals over a data network
rather than the traditional telephone lines.
PoE addresses one of the primary concerns
of VoIP: reliability and flexibility. PoE enabled
IP phones receive uninterrupted power
through the network, without the need for an
AC outlet for each phone.
Note:
Business conferencing / Colour Display
VoIP Phones / Video Collaboration
based IP Phones, typically require
PoE+ (802.3at)

16. PoE Applications: IP Surveillance
ProSAFE
Desktop
Tablet
ReadyNAS
Internet
Firewall
Modem
11AC Wireless Access
Point
Surveillance
PoE
VoIP
Phone
Server
Printer
IP Security Cameras and Devices:
Security cameras are traditionally located
near electrical outlets limiting their
effectiveness. Utilising the switching network
to mount cameras and access control
devices on ceilings, hallways, outdoor or
reception areas is significantly less
expensive.
Note:
PTZ cameras require 802.3at (PoE+)
Network cameras offer the following
advantages over Analog (or CCTV)
Simple: single cable for power and
video recording. Plus, no more tapes
Standards: use IP and Ethernet to
send traffic. Portable!

17. Cabling lenght, heating, …

18. PoE Budget
Home Electric Meter
Max. Power 2000W
M4300-52G-PoE+ (PA)
Max. Power 480W (1PSU)
What happens if the consumed power goes over the maximum?

19. PoE Budget
Home Electric Meter
Max. Power 2000W
M4300-52G-PoE+ (PA)
Max. Power 480W (1PSU)
Overheating or Short Circuit
Autoprotection
No more power for additional PD devices
Normal operating
X
X

20. PoE Pass Through
+ For hard to wire electrical installations, Pass through PoE switches
are the ideal solution
+ Only NETGEAR provides a choice of pass through options in a
Plus, Smart and Fully Managed configuration*
Data & PoE

21. PoE Applications: Critical Key Point
Wireless LAN
VoIP
IPSurveillance
LAN Segmentation (VLAN)
Traffic Prioritization (QoS)
Traffic Troughput (LAG LACP)

22. o Gli standard 802.3af, 802.3at e gli sviluppi futuri.
Collegare un dispositivo non PoE ad una porta PoE dello switch,
può danneggiare il dispositivo? ….
o Come disegnare l’impianto per integrare
correttamente il PoE? (Cablaggio, budget PoE, ….)
o Le soluzioni Netgear con supporto PoE

23. NETGEAR Switch Positioning
SoHo-based SoHo-based Enhanced SMB (5- max. 250 users) ME ( 150+ users)

24. Switching portfolio
Most comprehensive and versatile switching portfolio in the market,
now has more variety – with cloud management

25. SWITCH UNMANAGED FLEXIBLE POE
Netgear Switches PoE line-up

26. Netgear Switches PoE line-up

27. Netgear Switches PoE line-up

28. Power Supply Redundancy & Expansion

29. PoE Applications: Critical Key Point
Wireless LAN
VoIP
IPSurveillance
LAN Segmentation (VLAN)
Traffic Prioritization (QoS)
Traffic Troughput (LAG LACP)

30. NETGEAR Switch Positioning
SoHo-based SoHo-based Enhanced SMB (5- max. 250 users) ME ( 150+ users)

31. Product Naming Conventions
Speed Form Factor Ports Category PoE Stackable
Unmanaged Fast Ethernet: FS
Gigabit Ethernet: GS
1xx (desktop, metal)
2xx (plastic, SOHO)
3xx (metal, SOHO)
6xx (plastic, premium)
5xx, (13”, metal)
5-24 P
Click Switch
(Plus)
Gigabit Ethernet:GSS 1xx (plastic, metal) 8-16 E P
Web Managed
(Plus)
Fast Ethernet: FS
Gigabit Ethernet: GS
10G Ethernet: XS
1xx (metal)
5xx (13”, metal)
7xx (17”, rack-mount,
metal)
5-24 E P
Smart
Managed
Fast Ethernet: FS
Gigabit Ethernet: GS
10G Ethernet: XS
1xx (desktop, metal)
5xx (13”, metal)
7xx (17”, rack-mount,
metal)
8-52 T LP
P
PP (high
power)
X and/or S
(10G
stacking
ports)
Fully Managed Fast Ethernet: FSM
Gigabit Ethernet: GSM
10 Gigabit: XSM
Chassis Switch: XCM
41xx (L2+ / L3 Lite)
42xx (L2+ / L3 Lite)
72xx (L2+ / L3 Lite)
73xx (L3 Full)
43xx (L3 Full)
89xx (L3 Full)
12-52 P S

32. PoE key benefits
• Installation Cost Savings
Eliminates the need for electrical outlet installation
Dramatically reduces cost of deployment
No need for bulky AC power adaptors
• Simplifies Installation
Uses a single Cat5/5e/6 cable for both data and power
• Centralized Power Backup
Continuous operation during power interruptions
• Centralized Power Management
Devices can be remotely powered down for low usage and/or for security purposes
• SAFE Power
Will not damage Non-PoE devices or legacy peripherals

33. Thank you.
Your Network. Anytime. Anywhere.