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8851 and 8861 (SIP) freeze occasionally




I would like to know if anyone have been experiencing some freezing issues with 88XX phones? 


We first received the phones with the firwamre sip88xx.10-2-1-16 but since the phone was looping through reboots when connected to 2x or 3x 8800 modules, we upgraded to sip88xx.10-2-2-16. Since then, the phones freezes completely from time to time and needs to be disconnected. 

When frozen (which often happens when the calls are transferred to another extensions), there is nothing we can do at all on the phones.


There is no newer firmware  so I'm pretty much stuck here.

I'll have to try our other BNIB 8851 but at least one 8861 and one 8851 have the exact same behavior.



72 Replies 72


Hi,  we've deployed the 8851s on one or our sites, and we're having the same problem.  The receptionist's phone, which has an expansion module is the worse of all.  She complains about having to reboot the phone once a day at least because the screen goes dark and does not come on, or the phone is just unresponsive.  She now is saying that the keys on the KEM are not showing the line state, and if it does it takes a long time to update.  Phones are on firmware sip88xx.10-3-1-20, I don't think the KEM can be updated separately.  Not sure what to do next, the end users are not feeling very excited about the daily reboots...



one question your Lan is Cisco or another brand of switch , I have the same problem than you and my customer Lan is Enterasys



Mine is Cisco and we have seen the issue on 3750 and 3850 access layer switches.  

Ours is HP2920 stacked switches - still no issues reported so far since the firmware upgrade but we only have ~4-5 8851/8861.

This site still has 3750's, but we're deploying Brocades elsewhere...

Cisco Employee
Cisco Employee

It looks like there was no real fix in this thread - we now have phones running 11(5)1 experiencing similar issues and are struggling to pinpoint the issue or find a fix...

Just an update...  We have determined the new 8845 phones, new DMPs and newer APs are all doing the same thing.  Locking up and will not respond and the only thing that will bring them back on line is a shut or no shut.

Older phones, older APs are not experiencing any issues at all. 

I'll get back with the exact model numbers of the DMPs and APs. 

Still struggling with this slow down to lock up & needing a reset (power off)...  Could have something to do with a KEM attached..???

For what it worth, my 8851 et 8861 are still OK to this day.

I'm still running my 8851 with 1 8800 module and Bluetooth enable to connect my Nexus 6p phone. I have a Plantronics hw251 headset.

Same issue here we using 8841 phones on firmware sip88xx.11-5-1-18. Phones will Freeze. Screen is on but non responsive. Only way to fix is to unplug POE and back in. This happened on previous firmware as well.

TAC case is logged with Cisco but still no solution. Switches were suspected but full health check was done and nothing wrong with the Switches. 

Can you provide the SR# please - we're escalating with TAC and I've engaged the BU...

Same issue here with 8845 phones, DMPs and our AIR-CAP2602E-A-K9 aps.  Older aps and 6921s, 9971s are not locking up.  The only way to restore service is a shut and no shut or unplug the device and reconnect it.

Yup same issue here in our contact center. Most are using headsets. Running firmware 11-5-1-18. Anyone heard anything more on this? Thank you.

FYI - we got an ES that appears to have fixed our issue - 11-5-1ES-6 there are loads for the 78 and 88 series phones....

Do you by chance have a link? I can't seem to find that anywhere. Or did you have to ask TAC for that?

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