POE MODE B ON CISCO IE3300 Series Switch

[narshad36]

Hi ...

I am facing an issue.. I have FHF Industrial Phone that accepts 802.3af (Mode B) and 802.3bt (type 3). I have Cisco IE-3300-8U2X-A with Expansion Module IE-3300-8U2X-A. I have supplied 54VDC as Input to Cisco Switch. 

I used the command "power inline four-pair forced" on the interface where phone is connected. But Phone didn't get powered up. 

is 802.3bt is enabled by default? or we have to enable it? if we have to enable it.. shall I use "hw-module Switch UPOE-Plus" command?

Cisco Switch is having IOS XE 17.06.03.

Regards,

NA

[pieterh]

my suggestion about a cross cable was only for a test
normally between a client and a switch you use a straight cable ( 1:1 connected)
1) did you test with a straight cable ?
2) did you test if the phone powers on with an external power supply ? (it could be a DOA)

Interface gig 1/5
switchport mode access
spanning-tree portfast
power inline four-pair forced
shut
no shut
=> this is not the default configuration
=>use these commands
     default Interface gig 1/5
     Interface gig 1/5
          switchport mode access
          spanning-tree portfast
     end

[narshad36]

Yes! phone gets powered up with external power supply.

we didn't test with Straight cable, we'll do that as well.

[narshad36]

We checked with Cross Cable and Straight Cable .... But no success 

[aleivama]

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-9300-series-switches/220318-verify-differences-between-poe-802-3at-8.html

IEEE 802.3bt

• When IEEE 802.3bt mode is uded, Cisco UPOE devices function as 802.3bt Type 3 or Type 4 devices, and support up to Class 6 and class 8 respectively (refer the IEEE Power Classification table in the document) on every port.
• This is the procedure this standard states in order to allocate power:

      1. After device detection, the switch determines the device power requirements based on its type.

      2. The initial power allocation is the maximum amount of power that a powered device requires. The switch initially allocates this amount of power when it detects and powers the powered device.

      3. If the switch receives CDP messages from the powered device and as the powered device negotiates power levels with the switch through CDP power-negotiation messages, the initial power allocation can be adjusted. However, this is not needed as initially the switch allocates the maximum amount of power required, based on its class.

The switch classifies the detected IEEE device within a power consumption class. Based on the available power in the power budget, the switch determines if a port can be powered. 

• UPOE Devices are configured to use 802.3at mode, by default. To change the PoE standard to 803.bt mode, the command hw-module switch switch_noupoe-pluscommand can be used in the global configuration mode. A reload is needed:

Device# conf t
Device(config)#hw-module switch 1upoe-plus !!!WARNING!!!This configuration will power cycle the switch to make it effective. Would you like to continue y/n? Device# y

You can revert to 802.3at mode with theno form of the command:no hw-module switch switch_noupoe-plus. This command applies to both Type 3 and 4 802.3bt standards.

Verification

These showcommands can be used to monitor and verify PoE configuration:

Commands	Purpose
show platform	Displays the PID of the switch to verify if 803.bt is supported
show power inline gix/y/z detail	Displays the power details (Power mode, IEEE Class, Device type, Power negotiation and Four-Pair/Spare Pair support)
show power inline upoe-plus	Displays the PoE status for an interface that is enabled for 802.3bt or 802.3at compliant mode.