Good Morning Readers!
Today’s post is quick and dirty. If you work in an environment where Extension Mobility is widely used, the content of this post is probably common knowledge and you can stop reading here if you like.
For those curious about Extension Mobility, there are a ton of resources on the Internet that can show you how to use and configure it as well as how it impacts your CUCM licensing. If you don’t know what CUCM stands for, this probably isn’t the post for you.
I was recently dealing some odd behavior from one of the 7841 IP Phones in my lab. Despite the fact that I had logged out my Extension Mobility (EM) user, their details (their User Device Profile) were still showing up on the physical phone. I reset the phone, checked the cluster for DB errors, and scratched my head a lot. I then proceeded to smack my head when I remembered the logout profile configuration in CUCM.
If you know anything about Unified Communications Manager Express (UCME), you know that the logout profile is very common on this platform. EM cannot exist on UCME without it. In CUCM we get spoiled, we can use existing device configuration details and do not have to specify a logout profile, there is however still a place for one.
In a perfect world a logged out EM configuration (in CUCM) should look like this:
This denotes that when a user logs out of the phone, the phone will use whatever configuration data exists in CUCM.
If however, a logout profile gets set (as shown below), the phone will display that profile upon an EM logout.
This is exceptionally confusing when the profile that was just logged out happens to also be the logout profile!
Obviously this was a misconfiguration on my part. Instead of just checking the box to enable Extension Mobility, I also specified a user profile. This lead to several minutes (a good half hour) of me troubleshooting a problem that inevitably had no problem at all.
Thanks for reading and hopefully you got some enjoyment laughing at my screw-up.
-J
Justin On VOIP (and more) 
What are the device settings that are visible in the drop down list? Are those the profiles cached in CUCM or the phone itself? End user has logged from the phone, phone shows default config but in the cucm I can see a few profiles in the drop down list in the extension mobility section. Thanks
Hey Daniel, the “Current Device Settings” referenced in the drop down is the static CUCM configuration for the phone. If you were to select one of those drop-down profiles you would load the User Device Profile (UDP) that you select. What that means is that when the phone reboots, resets, factories, etc. it will get that UDP configuration as soon as it re-registers to CUCM. Therein lies the confusion! – Justin