Physically Moving Phone Concern and CER

[Esto]

In an Centralized single-cluster environment, if you have users that pick up their phones and physically move it to alternate locations. How do you prevent CSS call routing out the correct location? Using Local Route Groups ? For example, we have users that physically move to another location and dont tell anyone and their CSS routes calls out their previous location.

Another example, we have users at an office that are assigned Main_CSS. They go to a remote location and don't tell anyone, call 911 and the CSS routes it out the Main office. CER should then recognize that switchport, and have ERL callback back to that phone. But if the previous location was a FXS analog line wouldnt the location information generate from that Main_CSS location?

[Jonathan Schulenberg · Accepted solution]

I'm breaking my answer into three parts:

For non-emergency calls you can get the CSS to update using Device Mobility which is based on subnets. You associate one or more subnets to a Device Pool and CUCM will roam the device to another Device Pool when it registers from a subnet not associated to its home location. You may want to print the attached flowchart and stick it on your wall.

For emergency calls with an IP phone, you are correct: CER should notice either the new switch port the phone is advertising CDP on or the subnet it has moved to (depending on how you have CER configured).

Lastly, I'm struggling to understand the scenario for analog phones. Glossing over the question about why they have an analog phone for the moment: it shouldn't matter. When they get to the other office and plug in their analog phone, it will inherit whatever CSS/configuration is assigned to the FXS port in that office.

[Esto]

Thank you. Extremely helpful information. Device Mobility would certainly solve the issue of roaming devices and not having to constantly manage the CSS changes as they move. I am going to review the flowchart and see if I can implement a solution that makes sense in our environment.

Regarding analog lines, the reasoning is because there are no PRI's or SIP trunks so there are direct analog lines connected via FXO to the Gateway(Sorry I didnt realize I put FXS). However, Device mobility would change the CSS so calls wouldn'tt traverse this local gateway if the phone is moved, so this is basically irrelevant like you indicated.