The Bosch cameras connected to the S5720-SI failed to work

The customer reported that the Bosch cameras connected to the S5720SI failed to work.

Version: V200R010C00SPC600

By investigating on switch  found that the movement is not working for those cameras drawing less than 14W power. The Cameras drawing 14W is working fine.

<QAS-LAN-SWT-1>dis poe power                                                    

Codes: REFPW(Reference power), USMPW(User set max power),                      

CURPW(Current power), PKPW(Peak power), AVGPW(Average power)            

PortName               Class  REFPW(mW) USMPW(mW) CURPW(mW) PKPW(mW)  AVGPW(mW)

--------------------------------------------------------------------------------

GigabitEthernet0/0/1   4      30000     30000     15105     15635     14956    

GigabitEthernet0/0/2   4      30000     30000     14999     15529     14811    

GigabitEthernet0/0/3   4      30000     30000     12561     14416     12473    

GigabitEthernet0/0/4   4      30000     30000     12349     14893     12342    

GigabitEthernet0/0/5   4      30000     30000     14999     15582     14869    

Check the debug information as below:

<HUAWEI>t d 
Info: Current terminal debugging is on. 
<HUAWEI>t m 
Info: Current terminal monitor is on. 
<HUAWEI>debugging lldp all interface GigabitEthernet 0/0/3
<HUAWEI>d t 0

Packet sent from the camera to the switch:

Mar 28 2018 00:56:39.600.4+03:00 QAS-LAN-SWT-1 DBGCENTER/7/DEBUG:Receive Packet. (IfIndex=9)

Mar 28 2018 00:56:39.600.5+03:00 QAS-LAN-SWT-1 DBGCENTER/7/DEBUG:Process LLDP Packet Out String.(szTempStr= 01 80 C2 00 00 0E 00 07 5F 9B A3 56 88 CC 02 07 04 00 07 5F 9B A3 56 04 07 03 00 07 5F 9B A3 56 06 02 00 78 FE 09 00 12 0F 01 03 6C 00 FF FF FE 09 00 12 0F 03 00 00 00 00 00 FE 06 00 12 0F 04 05 EE FE 0C 00 12 0F 02 00 01 05 51 00 FF 00 82 FE 1A 00 12 BB 09 42 6F 73 63 68 20 53 65 63 75 72 69 74 79 20 53 79 73 74 65 6D 73 08 07 4E 6F 74 20 73 65 74 0A 07 4E 6F 74 20 73 65 74 0C 2F)

Mar 28 2018 00:56:39.600.6+03:00 QAS-LAN-SWT-1 DBGCENTER/7/DEBUG:Process LLDP Packet Out String.(szTempStr= 41 55 54 4F 44 4F 4D 45 20 49 50 20 73 74 61 72 6C 69 67 68 74 20 37 30 30 30 20 48 44 20 2D 20 49 50 20 53 75 72 76 65 69 6C 6C 61 6E 63 65 0E 04 00 80 00 80 00 00)

According to the collected LLDP debugging information, the power information in the packet sent from a camera is encapsulated in the 802.3at TLV. In the response packet sent by the switch, correct power information is also encapsulated in the 802.3at TLV. However, the response packet also contains the Extended Power-via-MDI TLV (another power negotiation mode) of TIA.

Do capture on switch as below:

In the packet sent from the camera, power information is encapsulated only in the Power Via MDI TLV.

In the response packet sent by the switch, correct power information is encapsulated in the Power Via MDI TLV. However, the packet also contains the Extended Power-via-MDI TLV of TIA, which records a power of 0.2 W. This affects the normal operation of the camera.

By default, in the response packet sent by the switch, correct power information is encapsulated in the Power Via MDI TLV. However, the packet also contains the Extended Power-via-MDI TLV of TIA, which records a power of 0.2 W. This affects the normal operation of the camera.

After the lldp dot3-tlv power 802.3at and undo lldp tlv-enable med-tlv power-over-ethernet commands are run on the corresponding interface, the switch uses only the Power Via MDI TLV in the LLDP packet sent to negotiate the power with the camera. This ensures that the camera works properly.

[Quidway-Ethernet0/0/3]lldp dot3-tlv power 802.3at
[Quidway-Ethernet0/0/3]undo lldp tlv-enable med-tlv power-over-ethernet