3.1.4 Ports—PoE Status
The Ports—PoE Status table reports major configurations and status PoE parameters. The following table lists the Switch PoE parameters (left columns) and the remote PD PoE parameters (right columns).
The list of parameters is as follows:
- #: Unit logical port numbers 1–6. However, while using the CLI interface, the ports are named as the following:
- interface GigabitEthernet 1/1—interface GigabitEthernet 1/4
- interface 2.5 GigabitEthernet 1/1—interface 2.5 GigabitEthernet 1/2
- PoE-BT Port Type: PoE port maximum power configuration. Power to PD is shut down when PD attempts to exceed the limit.
- Type4-90W: PoE-BT up to 90W on four pairs. Up to 45W on two pairs
- Type3-60W: PoE-BT up to 60W on four pairs. Up to 30W on two pairs
- Type3-30W: PoE-BT up to 30W on four pairs. Up to 30W on two pairs
- Type3-15W: PoE-BT up to 15W on four pairs. Up to 15W on two pairs
- Power Management Mode: Power Management Configuration mode affects how PD class and power consumption affects the unit's overall free available power.
- Dynamic: PoE port dynamic real-time power consumption is deducted from the overall PoE-free power budget, while ignoring the PD class or the PoE port maximum power.
- Static: PoE port type power configuration (as Type4-90W) is deducted from the overall PoE free power budget after the PoE port is turned on, while ignoring the PD actual power consumption. Next, PD might not be turned on when the free available power is lower than the PD requested power. Initial PD requested power is based on the PD class and the PD auto-class.
- Hybrid: Mixture of dynamic and static power management based on PD advertising its power requirements by sending LLDP IEEE® 802.3 power through the MDI TLV protocol. Every PoE port configured as Hybrid acts as if it is configured as Dynamic, if it does not receive any Power Over-MDI TLV within the LLDP packet sent by the PD. After receiving IEEE 802.3 power through MDI TLV, the port also switches to the Static Power mode, limiting PoE port maximum power as per the PD requested power plus user-configured cable loss based on user cable length configuration. Static PoE port maximum power might change based on PD LLDP IEEE 802.3 power through MDI TLV advertised values.
- Status: Reports the latest PoE port status
- –-: PoE port is enabled. No PoE-PD.
- On: PoE power is applied to PD
- Disabled: PoE is disabled (non-related to Ethernet data link state)
- Overload: PD power consumption exceeded its maximum limit. The power is shut down.
- Fault: Fails to turn on the connected PD device. The following are the possible reasons:
- Non-standard PD was connected
- PD class error
- PD underload (PD power consumption is too low)
- Shortage or invalid capacitor value
- PD was disconnected (temporary recovery from underload)
- PSE Fault. Not enough free power is available to turn on the PD device. Other rare possible reasons: Power supply voltage is out of range, voltage is injected into the Ethernet port, and port over temperature.
- Requested Power: PoE PD requested power based on PD Class.
- Class 8 = 90W
- Class 5, 5 = 90W
- Class 6 = 60W
- Class 4, 4 = 60W
- Class 4 = 30W
- Class 3 = 15W
- Class 2 = 7W
- Class 1 = 4W
- Class 0 = 15W
- Assigned Power: The maximum power that was
assigned to PD. Trying to consume above this limit causes the PD to be turned off.
When enabling the Legacy PD_Class mode, the assigned PD class might defer from the
measured PD class, leading to Assigned-Power differing from Requested-Power.
Assigned power might defer from requested power for the following reasons:
- Demotion: Free available power is less than PD requested power. PoE-BT uses the demotion option to offer a lower power value to the PD. If PD agrees to the lower power value, then it is turned on with a lower power limit.
- PoE Port maximum Power: PoE port maximum power configuration is lower than the newly inserted PD power class. For example, connecting a 90W PD class-8 to a PoE port configured as Type3-60W.
- Delivered Power: Temporarily PD power consumption
- Assigned Class: PD maximum power consumption is determined by the class it is assigned by the PoE controller (8=90W / 5,5=90W / 6=60W / 4,4=60W / 4=30W / 3=15W / 2=7W / 1=4W/ 0= 15W). Mostly, the PD Assigned-Class matches with the PD-Measured-Class. The PD-Assigned- Class differs from the PD-Measured-Class in one of the following scenarios:
- PoE Power Demotion: As per the IEEE 802.3bt specification, when the PoE port maximum available power is less than the PD requested power, the PoE port might offer the PD a lower maximum power value. It is up to the PD to decide to accept the new offer, agreeing to consume less power.
For example, PD class-8 (90W) is being connected while PoE-Port has only 60W spare power left. Here, the port offers PoE class-6 (60W). If PD accepts the offer, then Measured-Class is class-8 while Assigned-Class is class-6.
- Legacy PD-Class Mode = PoH. Port Mode = Plus: PoE-AT DSPD PD class 4, 4 is given 90W as if it is class 5, 5 (2×45W). PoE-AT SSPD PD class 4 is given 45W as if it is class 5.
- Legacy PD-Class Mode = Ignore PD-Class. Port Mode = Type4-90W: Any DSPD class-x, x is given 90W as if it is class 5, 5 (2×45W). SSPD PD class-x is given 45W as if it is class 5.
- Legacy PD-Class Mode = Ignore PD-Class. Port Mode = Type3-60W: Any DSPD class-x, x is given 60W as if it is class 4, 4 (2×30W). SSPD PD class-x is given 30W as if it is class 4.
- PoE Power Demotion: As per the IEEE 802.3bt specification, when the PoE port maximum available power is less than the PD requested power, the PoE port might offer the PD a lower maximum power value. It is up to the PD to decide to accept the new offer, agreeing to consume less power.
- PD Measured Class: Remote PoE-PD measured classes 1–8 for SSPD or class 0, and classes 0-5 for DSPD.
- PD Auto Class Support: Report, if the remote PoE-BT PD device advertises that it is supporting PoE Auto Class regardless of the unit Auto Class configuration. When enabled and supported by the PoE-PD device, PoE port maximum power allocation is determined by the power consumed by the PD during the Auto Class negotiation phase instead of the PD class.
- PD Requested Power Over LLDP: When supported by remote PoE-PD, report remote PoE PD requested power using LLDP Power Over-MDI. If PoE-LLDP is disabled, (N/A) appears to the right or PD request power, ignoring PD request power using only PD class for determining PoE power request. When PoE-LLDP is enabled, PD PoE power request over LLDP replaces the PoE PD class. However, it never exceeds the PD class maximum power. Cable loss based on cable length configuration is added on top of the PD LLDP requested power. The PoE Power Management Configuration mode controls the power deducted from the unit-free available power.