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Knowledge Base

S5700-LI-SI-PWR connect cisco cp9971 IP phone video call failure

Publication Date:  2015-06-19  |   Views:  2351  |   Downloads:  0  |   Author:  SU1001755392  |   Document ID:  EKB1000079396


Issue Description

Huawei Product:

S5700-PWR-SI / LI

Version: (V200R003C00SPC300)

Patch: (V200R003SPH005)


Cisco Product:

IP Phone CP-9971

Version: sip9971.9-4-1-9


Network Connection:

Cisco CUCM --- Core --- c3750 --- S5700 --- Cisco CP9971 video iphone

Cisco CUCM --- Core --- c3750 --- c2960 --- Cisco CP9971 video iphone


Issue description:

As customer mentioned, all Cisco IP phone 9971 power up by both Cisco PoE switch 2960X and Huawei PoE switch S5700-52TP-PWR-SI in different floor bind to different VLAN, they found the video call is one way video call.

After call setup, IPT connecting Huawei switch could show the video on screen but IP phone connecting Cisco switch was unable to display video on screen that should deliver from Huawei side IP phone, but voice is normal.

Alarm Information

Cisco IP Phone screen display:

"The phone is unable to power this accessory"

Handling Process

Test process:

1.       Connect IP phone on test Huawei switch to Cisco switch with same vlan B, initial video call, one way video issue reproduced again.

2.       Connect two IP phones on test Huawei switch, video call failure on two IP Phone



1.       Checked the poe power and IP phone consumed power on Cisco switch and Huawei switch and found IP phone on Cisco switch drawn almost double power than IP phone on Huawei switch.

2.       Cisco 9971 video call poe requirement is 802.3at standard and might require draw over 15.4W power, so we suspected this is power issue

3.       Ddouble checked the phone status during video call and found the camera on IP phone connecting Huawei switch was off with no light, but Cisco side IP phone did light up on the camera

4.       After rebooted Cisco IP phone on Huawei switch, the phone’s display shows a message once “The phone is unable to power this accessory”.



=============== Cisco poe output =================

Cisco-2960X#sh power inline | i 9971

Interface Admin  Oper  Power   Device   Class Max (Watts)                           

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

Gi1/0/17  auto   on         14.4    IP Phone 9971       3     30.0

Gi1/0/25  auto   on         19.1    IP Phone 9971       3     30.0


=============== Huawei poe output ===============

[Quidway]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   -      -         30000     0         0         0       

GigabitEthernet0/0/2   3      15400     30000     7155      7420      7061





Root Cause

Root cause analysis and issue solved:

1.       To solve the device does not transmit a specific model of PD of LLDP packets to cause PD does not work

2.       resolved version - V200R003C00SPC300
Involved product model
- S2750-EIS5700-LIS5700-10P-LIS5700-X-LIS5700-SIS5700-EIS5710-EIS5710-HI

3.       The equipment is linked to the ability to obtain power through the standard 802.3at PD (Powered Device), PD cannot be normal power

4.       Device didn’t negotiate correct power by LLDP packet sent by PD

5.       According to PD device’s LLDP packets, TLV contains the corresponding information in LLDP packets


Verification process & solution:

  1. Apply latest patch to address the poe power issue on Huawei switch.
  2. enable LLDP globally and two commands on interfaces connecting IP phone to deliver TLV information to neighbor device to draw enough poe power.
  3. After activate patch, require configure these two command on the switch interface

    a.       lldp dot3-tlv power 802.3at

    b.      undo lldp tlv-enable med-tlv all

  4. Reboot IP phone.
  5. The phone is unable to power this accessory” disappear and show normal message
  6. Tested voice and video call result normal


Use power injector or power supply to test if suspecting POE problem for third party poe device