Technical data

224 FastIron Ethernet Switch Administration Guide
53-1002637-02
LLDP-MED attributes advertised by the Brocade device
8
Extended power-via-MDI information
The extended Power-via-MDI TLV enables advanced power management between LLDP-MED
Endpoints and Network Connectivity Devices. This TLV provides significantly more information than
the 802.1AB Power-via-MDI TLV referenced in “Power-via-MDI” on page 212. For example, this TLV
enables an Endpoint to communicate a more precise required power level, thereby enabling the
device to allocate less power to the Endpoint, while making more power available to other ports.
The LLDP-MED Power-via-MDI TLV advertises an Endpoint IEEE 802.3af power-related information,
including the following:
• Power type – indicates whether the LLDP-MED device transmitting the LLPDU is a power
sourcing device or a powered device:
• Power sourcing device/equipment (PSE) – This is the source of the power, or the device
that integrates the power onto the network. Power sourcing devices/equipment have
embedded POE technology. In this case, the power sourcing device is the Brocade POE
device.
• Powered device (PD) – This is the Ethernet device that requires power and is situated on
the other end of the cable opposite the power sourcing device.
• Power source – The power source being utilized by a PSE or PD, for example, primary power
source, backup power source, or unknown.
For Endpoint devices, the power source information indicates the power capability of the
Network Connectivity Device it is attached to. When the Network Connectivity device advertises
that it is using its primary power source, the Endpoint should expect to have uninterrupted
access to its available power. Likewise, if the Network Connectivity device advertises that it is
using backup power, the Endpoint should not expect continuous power. The Endpoint may
additionally choose to power down non-essential subsystems or to conserve power as long as
the PSE is advertising that it is operating on backup power.
NOTE
Brocade devices always advertise the power source as “unknown”.
• Power priority – The in-line power priority level for the PSE or PD:
• 3 – low
• 2 – high
• 1 – critical
• unknown
• Power level – The total power, in tenths of watts, required by a PD from a PSE, or the total
power a PSE is capable of sourcing over a maximum length cable based on its current
configuration.
If the exact power is not known for a PSE or PD, it will advertise the power level associated with
its 802.3af power class (listed in Table 16).
TABLE 16 802.3af power classes
Power class Minimum power level output at the PSE Maximum power levels at the PD
0 15.4 watts 0.44 – 12.95 watts
1 4.0 watts 0.44 – 3.84 watts