Power over Ethernet (PoE) is supported only on the 7210 SAS-Dxp 16p and 7210 SAS-Dxp 24p.
The 7210 SAS-Dxp 16p and 7210 SAS-Dxp 24p support PoE in accordance with the 802.3af, 802.3at, and 802.3bt standards. This feature allows these platforms to supply power to connected PoE devices, such as telephones, CCTV cameras, and other PoE standard compliant devices.
The following PoE functionalities are available:
The 7210 SAS-Dxp 16p and 7210 SAS-Dxp 24p support 802.3af (PoE), 802.3at (PoE+), and 802.bt (PoE++ and HPoE). All ports support PoE and PoE+. only the first four copper ports support PoE++ and HPoE. The ports can be used to connect PoE, PoE+, PoE++, or HPoE devices, or a combination of both simultaneously, as long as the power drawn is within the device system limits.
Only Alternative A, as described in the 802.3af and 802.3at standards, is supported on the 7210 SAS.
The 7210 SAS-Dxp 16p and 7210 SAS-Dxp 24p support classification Type 1, Type 2, Type 3, and Type 4 PoE devices (PDs) using the physical layer classification mechanism. The physical layer classification mechanism supports both the single-signature and dual-signature classification mechanisms.
The user must configure the maximum available PoE power budget using the configure system poe max-poe-power-budget command before enabling PoE on any of the ports. See the 7210 SAS-D, Dxp, K 2F1C2T, K 2F6C4T, K 3SFP+ 8C Basic System Configuration Guide for more information about this command.
The 7210 SAS-Dxp 16p and 7210 SAS-Dxp 24p support the PoE type and class-based power allocation method, which allocates power based on the identified PoE type and class using a physical layer classification mechanism. The 802.3af, 802.3at, and 802.3bt standards define four PoE types (Type 1 (up to 15W, Type 2 (up to 30 W), Type 3 (up to 60W), and Type 4 (up to 90 W)) and the power that can be allocated or requested by a particular class. The standards define eight classes: Class 1, Class 2, Class 3, Class 4, Class 5, Class 6, Class 7, and Class 8. These classes are used to allow PoE devices to request power based on their needs. If there is not enough power available to supply the identified class, power is denied to the connected PoE device. Each 7210 SAS device has a limit on the maximum amount of power it can provide. If the total power requested by the PDs connected to PoE-enabled ports exceeds this threshold, the 7210 SAS device denies power to the other PD. When power is denied to the PD, the port is operationally up, even though power is not supplied to the port. If power is applied successfully or denied to the port, the system logs an event.
The software accounts for power requirements based on the PD type and does not consider the PoE class within a type (a PoE device uses 15 W, a PoE+ device uses 30 W, a PoE++ device uses 60 W, and a HPoE device uses 90 W).
For example, if the user configures one PoE port, the software deducts 15 W from the configured max-poe-power-budget. If the user configures two PoE ports and two PoE + ports, the software deducts 90 W from the configured max-poe-power-budget (assuming the configured value is greater than or equal to 90 W). If the user configures a value of 100 W and attempts to configure four PoE+ ports, the software deducts 30 W from the configured max-poe-power-budget for the first three configured PoE+ ports using a total of 90 W (10 W are remaining). When the user configures the fourth port, the configuration fails because only 10 W are available, which does not meet the power requirement for the fourth PoE+ port.
Only DC power is supplied to connected PDs. It is supported for PDs that use injectors where an AC/DC wall device is used to power a remote PoE device.
The software monitors the PoE port, detects faults and events, and raises traps. The software displays this information in the status report. The following events and faults are detected and are notified to the user:
supplying power event
This event is generated when power is supplied to a connected PoE device after successful detection and classification.
denied power event
This event is generated when power is denied to a connected PoE device after successful detection and classification.
disconnect event
This event is generated when a connected PoE device is disconnected from the port and stops drawing power from the node.
fault events
These events are generated for overload, short-circuit, and other events. Software clears the fault when the fault no longer exists.
If a port enabled for PoE is shut down, the power supplied to the port is disabled. It restores power when the no shutdown command is executed, if the request does not exceed the power budget.