Device Mobility is a new feature of CUCM allows CUCM endpoints to be dynamically reconfigured based on their actual location as determined by the IP address that is used by the device.It enables CUCM to determine if the IP phone is at its home location or at a roaming location. CUCM uses the device's IP subnets to determine the exact location of the IP phone. By enabling device mobility within a cluster, mobile users can roam from one site to another, thus acquiring the site-specific settings. Cisco Unified CallManager then uses these dynamically allocated settings for call routing, codec section, media resource selection, and so forth.
The following are key characteristics and features of Device Mobility:
Device Mobility allows users to roam between sites with their IP Phones. Typically, these are Cisco Unified Wireless IP Phones or Cisco IP Communicator Phones.
When the device is added to the network of roaming sites, it is first assigned with an IP address. Because the IP networks are different in each site, CUCM can determine the physical location of the IP Phone based on its IP address.
Based on the physical location of the IP Phone, CUCM reconfigures the IP Phone with site-specific settings.
Roaming-sensitive settings ensure that the roaming device uses local media resources and SRST references. In addition, they ensure the correct use of codecs and CAC between sites. Typically, this is always desired when a device roams between different sites. It is not required when the device moves only between IP subnets within the same site. Therefore, the recommendation is to assign all device pools that are associated with IP subnets (DMI) that are used at the same site to the same physical location. This results in phone configuration changes only when the phone roams between sites (physical locations) and not in a situation where a phone is only moved between different networks of the same site.
Device Mobility-related settings impact call routing. By applying the device CSS, AAR group, and AAR, CSS calls are routed differently. The settings at the roaming device pool determine which gateway will be used for PSTN access and AAR PSTN calls based on the device CSS and AAR CSS. They also determine how the number to be used for AAR calls is composed based on the AAR group.
Such changes can result in different dialing behavior. For instance, when you roam between different countries, the PSTN access code and PSTN numbering plans might be different. For example, to dial the Austrian destination +43 699 18900009, users in Germany dial 0.0043 699 18900009, whereas users in the U.S. have to dial 9.01143 699 18900009.
German users who roam with their softphones to the U.S. might be confused when they have to use U.S. dialing rules access code 9 instead of 0 and 011 instead of 00 for international numbers. To prevent this confusion, suppress the application of Device Mobility-related settings. You do this by assigning device pools that are to be used at sites with different dialing rules to different Device Mobility Groups and different physical locations. Now, when a user roams with a device from Germany to the U.S., all the roaming-sensitive settings are applied, but the Device Mobility-related settings are not applied. The phone now uses the PSTN gateway and dial rules of its home location even though the user moved to another site. The user does not have to adapt to the dial rules of the local site to which the phone was moved.
Some of the benefits of Device Mobility
All location-dependent parameters can be dynamically reconfigured by Device Mobility. Thus, the phone keeps its user-specific configuration, such call-forwarding settings,directory number, speed dials and refers location-specific settings such as region, location, and SRST reference to the actual physical location.
To configure the Device Mobility follow the below mentioned steps:-
Enable the device mobility mode in the Service Parameter Configuration or Phone Configuration window.
Configure physical locations.
Configure device mobility groups.
Configure subnets and assign one or more device pools to a subnet in the Device Mobility Info window.
In the Device Pool Configuration window, update your device pools for device mobility settings, if you have not already done so.
If you have not already done so, update your dial plans for device mobility; for example, update calling search spaces, AAR group settings, and so on.
2. To configure the Device Mobility Mode setting for a specific phone, perform the following tasks:
To add a physical location for a device pool, use the following procedure.
To configure a device mobility group, which supports the device mobility feature, use the following procedure.
Choose System > Device Mobility > Device Mobility Group.
1. Choose System > Device Pool.
The physical location and the Device Mobility Group themselves are not applied to the configuration of a phone but are used only to control which settings to apply.
When the phone has device mobility mode enabled, you can view the roaming device pool settings by clicking View Current Device Mobility Settings next to the Device Mobility Mode field in the Phone Configuration window. If the device is not roaming, the home location settings display
The overlapping parameters for roaming-sensitive settings are Media Resource Group List, Location, and Network Locale. The overlapping parameters for the Device Mobility-related settings are Calling Search Space (called Device Mobility Calling Search Space at the device pool), AAR Group, and AAR Calling Search Space. Overlapping parameters configured at the phone have higher priority than settings at the home device pool and lower priority than settings at the roaming device pool.
Consider the following information when you configure device mobility in Cisco Unified Communications Manager Administration:
•When the Device Mobility Mode is set to Default in the Phone Configuration window, the Device Mobility Mode service parameter determines whether the device is enabled for the device mobility feature.
•Cisco Unified Communications Manager uses the longest match rule to match IP addresses and subnets, meaning the best match uses the largest number of bits in the IP subnet mask. For example, the IP address 220.127.116.11 matches the subnet 18.104.22.168/24 rather than the subnet 22.214.171.124/16.
•If no device mobility information entries match the device IP address, the device uses the home location device pool settings.
•You assign the device pool to the phone device in the Phone Configuration window; you assign device pools to subnets in the Device Mobility Info Configuration window.
•You can assign one or more device pools to a subnet address. Cisco Unified Communications Manager assigns device pools for the same subnet to roaming devices in round-robin fashion; for example, roaming device 1 gets assigned the first device pool in the list, and roaming device 2 gets assigned the second device pool in the list. This process allows you to load share when you expect a large number of phones to roam into an area, such as a meeting in the head office that employees from all branch locations will attend.
•Although physical location does not represent a required setting in the Device Pool Configuration window, you must define a physical location for a device pool to use the device mobility feature. Be sure to configure physical location for the home location device pool and for the roaming device pool.
•After the device mobility structure is in place, you can turn device mobility on for IP phones that support device mobility.