It’s a feature which allows CUCM to determine whether the phone is in its home location or a roaming station.
By enabling this feature users can roam from one site to another site and acquire the site-specific settings such as Codecs, MRGL, Call routing, SRST etc.
CUCM then uses these settings for the calls. These settings are collecting from the Device Pool-->Roaming Sensitive settings.
Scenario
Site name: SITE-A SITE-B
Username: USER-A USER-B
Subnet: 192.168.2.0/24 10.1.1.0/24
Device pool: SITE_A-DP SITE_B-DP
DMG: SITE_A-DMG SITE_B-DMG
DMI: SITE_A-DMI SITE_B-DMI
PL: SITE_A-PL SITE_B-PL
USER-A is moving from SITE-A to SITE-B, if we don’t have device mobility enabled, USER-A will be resuming with the existing call settings.
For ex: USER-A want to make an outbound call definitely call will be reaching out through the Local Gateway of SITE-B which is illegal according to TRAI in India. For avoiding these kinds of glitches, we can use Device Mobility.
Configurations:
- Service Parameter Configuration
System > Service Parameters>Select Server>Cisco Call Manager service
Device Mobility Mode: ON (This is using for enabling this feature in cluster wide or we have to manually enable it in the phone. Device mobility value in phone will be either ON/OFF/Default. If it is default, then it uses service parameter value or it use the value in phone)
Display Device mobility location during phone registration: TRUE (This is using for displaying "Device in Roaming Location/ Device in home location" in phone screen.)
- Create Device Mobility Group (DMG).
System>Device Mobility>Device Mobility Group (Name and description)
- Create Device Mobility Info (DMI).
System>Device Mobility>Device Mobility Info (Here I am providing SITE-B details)
Name: SITE_B-DMI
Subnet: 10.1.1.0
Subnet Mask (Bit size) *: 24
Device pool: SITE_B-DP
(How it works =When a phone registration request received to CUCM It checks its IP address If it match to subnet 10.1.1.0/24 it provide Roaming Sensitive settings values of SITE_B-DP. This is not the completed flow please go to bottom of this page and understand the complete working principle of Device Mobility.)
- Create Physical Location.
System > Physical Location (PL).
- Apply the DMG and PL to the appropriate DP under Roaming Sensitive settings. Also update the other values in Roaming Sensitive settings as per our requirement.
Working Principles
- USER-A is moved from SITE-A to SITE-B and powered on his phone.
- His phone pushed a registration request from SITE-B to CUCM.
- CUCM checks the IP address of the phone.
- It matches with subnet 10.1.1.0/24 (SITE-B)
- Device Mobility trigger from this point.
- As per the Device Mobility Info: if subnet match with 10.1.1.0/24 It has a Device pool associate: SITE_B-DP.
- Then CUCM check the Physical Location in Phone's device pool (SITE_A-DP) and the Physical Location of the Device pool which is obtained from Device Mobility Info (ie: SITE_B-DP)
- If both the Physical Location are different, CUCM push the Roaming Sensitive settings values mentioned in Device pool which is obtained from Device Mobility Info (ie: SITE_B-DP) to the phone.
- We can check these values from Device page>Device Mobility Mode >View Current Device Mobility Settings.
- It uses SLRG too even though it is not appearing in the View Current Device Mobility Settings