Factory Reset a Cisco Cius

There are several reasons that you need to factory reset series, you will know the reason when you need to factory reset it.  :)
These are the steps
1. Power down the device.
2. Keep the settings key and back key on the device pressed(the outer 2 keys at the bottom of the device) and power it up.
3. You will see that it powers on and a red LED next to the front camera will start blinking.
4. Once it starts blinking press the volume buttons + and - at the side of your device for 6 times alternately. i.e., + - + - + -
5. Once this sequence is pressed, you will see a solid red light for a while and this confirms that the factory reset is going on.
6. After the reset is done the device will boot up.

Different Call Park experience with 9971

My environment:  UCM 8.5.1.10000-26

When you have a 79xx phone and 99xx phones and with both of them configured with Call Park, you will find the end user experience is quite difference.

For the old 79xx phones:

1. Phone A (7965) calls Phone B (7965)
2. Phone B answers and parks the call at 1234
3. Phone B display shows "Call Park at 1234", no light on the line button, you can make new call with Phone B using the normal method

For the new 99xx phones:
1. Phone A (7965) calls Phone B (9971)
2. Phone B answers and parks the call at 1234
3. Phone B will shows

4567
Parked on 1234

and a Resume softkey.  The indicator of the 1st session key on the right is on.
4.  You can press the Resume softkey to get back the call, as if the call is on hold.  Or you can press the 2nd session key to make new calls.  You can also retrieve the call from other phone by call in the call park number.

This is correct as per design, although the behavior is contradictory to the old 79xx phones.

Detail information in Cisco bug toolkit:
http://tools.cisco.com/Support/BugToolKit/search/getBugDetails.do?method=fetchBugDetails&bugId=CSCta34868