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IP Phone 8821 common issues

Hello, dear support community.
We are facing some problems with 8821 from time to time: it
- periodically loses connectivity with its wifi AP being within the range
- might freeze while transferring a call
- constantly requires IP from DHCP server (each 4 seconds)
- standby battery life is way more shorter than it climes in the datasheet
At phone configuration:
Bluetooth is disabled
Scan Mode = Auto
CUCM 10.5
WLC 2504 Software Version
18 Replies 18

Leo Laohoo
Hall of Fame
Hall of Fame
These are known issues with the 8821. The firmware is not yet that stable.

Paul Austin
Level 4
Level 4

There are loads of problems with these. I would seriously recommend - no insist that you load the latest SR6 release as you have done. Failure to do so could "brick" your phones and then you need to RMA them. There are also loads of recommendations for the wireless environment - there is a 200+ page document you need to go through as well.

Hello Fedor,

8821 phones are particulary picky phones regarding the wireless enviroment that is required for them to work properly.

8821 have a deployment guide that you must follow if you want the phone to perform at its best, please read it carefuly and throughtly.


Best Regards, Jaime.

If you find this helpful please rate.


Have changed from DHCP to Static. Watching for changes.

We may be seeing connctivity problems connected to the battery. Still assessing this but our 8821's are with Cisco BU as we have so many problems.

Recently deployed 464 wireless 8821 SIP phones and the most recent troubles are:

1. Magnet strip for charging becomes dislodged and left in multi-charger.

2. The middle battery "copper" connection inside device comes lose or falls off.

3. The device will mysteriously turn back on when power button is pressed and device powers down?


We did have the other issues listed and upgraded firmware provided from Cisco engineers (not published firmware on For the most part the devices have replaced the 7925 SCCP devices, but we have had some learning curves during deployment. I recommend following the read me when installing and provide a stable 5 GHz wireless network. The wireless controllers and SIP profile on CUCM is crucial and some profile timers will make or break you. The USB connection when programming devices will give you fits, and I have abandoned trying to program devices this way if the device will not conform. Finger banging the profile, SSID and pre shared key is mentally easier than trying to break into the phone with USB connection (on some not all).

Good luck....


@dkikko2 wrote:

1. Magnet strip for charging becomes dislodged and left in multi-charger. 





Leo, we were informed from Cisco that this anomaly was repaired on devices manufactured after 01-01-18. Cisco is unable to confirm what S/N or lot numbers can confirm manufacture date after repair statements (bug) was made. Our test program included 34 8821 devices deployed 03-10-18 that rendered 7 devices with this defect. Full deployment of 464 on 07-09-18 has not returned this defect (yet), however the middle battery connection has development with 6 devices to date. Overall the 8821 is a bit tempestuous and Cisco is riding the storm to provide a stable platform. 


23 Cisco 8821 devices have returned with the middle battery connecting pin either missing or damaged. 8821 bad 7-21-19.jpg8821 bad connector 1-29-19 30.jpgAnother 8821 4-4-2019 30.jpg

Pictures shows the phones to be manufactured on July 2018.
Did all of the phones have the same manufacturing date?

I have the same problem too.

Are there any fixes that you came across mate?

Well in the end we had Cisco replace all of our 8821's as it got very political. The latest code seems much more stable but we had hardware issues hence the swap out.

After a half of a year problems was solved by installing the latest software with fixed bags.

i experience weird issues also

have 5 of those at a deployment.

2 of them at totally random intervals appear turn them selves off while on charger. 

i think they just crash.

i turn them back on and they are fully charged.

is not everyday totally random.

the other 3 have no issue or so ever

installed the latest firmware and seems made some difference but insident occured again after a couple weeks.