8.3 Device Mobility Characteristics

This topic describes the important characteristics and features of Cisco Unified Communications Manager Device Mobility.

  • Device Mobility can be used in multisite environments with centralized call processing.
  • Device Mobility allows users to roam between sites with their Cisco IP phones (typically softphones or Cisco Unified Wireless IP phones).
  • IP phones are assigned with a location-specific IP address by DHCP.
  • Cisco Unified Communications Manager determines the physical location of the IP phone based on the IP address that is used by the IP phone.
  • Based on the physical location of the IP phone, the appropriate device configuration is applied.

Device Mobility can be used in multisite environments with centralized call processing. It supports SCCP or SIPCisco IP phones.

Device Mobility allows users to roam between sites with their IP phones. Typically, these phones are softphones or Cisco Unified Wireless IP phones.

When the device is added to the network of roaming sites, it is first assigned an IP address. Because the IP networks are different for each site, the Cisco Unified Communications Manager can determine the physical location of the IP phone, based on its IP address.

Based on the physical location of the IP phone, the Cisco Unified Communications Manager reconfigures the IP phone with site-specific settings.

Device Mobility: Dynamic Phone-Configuration Parameters

This section shows the two types of phone-configuration parameters that can be dynamically assigned by Device Mobility.

Two types of phone settings can be applied by Device Mobility:

  • Roaming-sensitive settings:
    1. Standard Local Route Group
    2. Date/Time Group
    3. Region
    4. SRST Reference
    5. Media Resource Group List
    6. Location
    7. Network Locale
    8. Physical Locations
    9. Device Mobility Group
  • Device mobility-related settings:
    1. Device Mobility CSS
    2. AAR CSS
    3. AAR Group
    4. Calling Party Transformation CSS
    5. Called Party Transformation CSS

Device Mobility can reconfigure site-specific phone-configuration parameters that are based on the physical location of the phone. Device Mobility does not modify any user-specific phone parameters or any IP phone button settings such as directory numbers.

The phone-configuration parameters that can be dynamically applied to the device configuration are grouped into two categories:

  • Roaming-sensitive settings:
    1. Date/Time Group
    2. Region
    3. Location
      Note

      The Date/Time Group, Region, and Location settings are configured at device pools only.

    4. Network Locale
    5. SRST Reference
    6. MRGL
      Note

      The Network Locale, SRST Reference, and MRGL settings are overlapping parameters. That is, they are configurable at phones and at device pools.

    7. Physical Location
    8. Device Mobility Group
      Note

      The Physical Location and Device Mobility Group parameters are used to determine which settings should be applied to a roaming phone (none, the roaming-sensitive settings only, or the roaming-sensitive settings and the settings that are related to Device Mobility). They are not phone-configuration parameters themselves. Therefore, they are not applied to the phone configuration like the other listed roaming-sensitive settings are. They are used only in the decision on changing the phone configuration and how to change it. Consequently, they cannot be overlapping and are configurable only at device pools.

    9. Standard Local Route Group
  • Device Mobility-related settings
    1. Device Mobility CSS
    2. AAR CSS
    3. AAR Group
    4. Calling Party Transformation CSS
    5. Called Party Transformation CSS
      Note

      All listed Device Mobility-related settings are overlapping parameters; that is, they are configurable at phones and at device pools.

      However, the Device Mobility CSS is called Calling Search Space in the Phone Configuration window (at the device level). It does not overlap with the CSS that is configured at the line level. The Calling Party Transformation CSS of the device pool maps to the Remote Number – Calling Party Transformation CSS and the Called Party Transformation CSS of the device pool maps to the Caller ID for Calls from This Phone – Calling Party Transformation CSS, and both CSSs are configured at the phone (device level).

Roaming-sensitive settings are settings that do not have an impact on call routing. Device Mobility-related settings, however, may have an impact on call routing because they modify the device CSS, AAR group, and AAR CSS. Depending on the implementation of Device Mobility, roaming-sensitive settings only—or both roaming-sensitive settings and Device Mobility-related settings—can be applied to a roaming phone.

The GUI does not show the local route group in the roaming-sensitive settings pane. Nevertheless, the local route group is a roaming-sensitive setting and is updated when the physical locations of the home device pool and the roaming device pool are different. The called-party transformation CSS is shown in the Device Mobility-related settings pane of the GUI, but this setting does not apply to IP phones and hence is not a Device Mobility-related setting, although it is shown as such in the GUI.

Device Mobility: Dynamic Configuration by Location-Dependent Device Pools

This section describes where location-dependent configuration is stored in the Cisco Unified Communications Manager database and how the applicable set of parameters is chosen.

Main Device Pool

  • Region
  • Location
  • SRST Reference
  • Device Mobility CSS
  • AAR CSS
  • AAR Group

Remote Device Pool

  • Region
  • Location
  • SRST Reference
  • Device Mobility CSS
  • AAR CSS
  • AAR Group

As shown in the figure, the location-dependent parameters (that is, roaming-sensitive settings and Device Mobility-related settings) are configured at device pools. Based on the IP subnet that is used by the phone (which is associated with a device pool), the Cisco Unified Communications Manager can choose the appropriate device pool and apply the location-dependent parameters. With Device Mobility, the Cisco Unified Communications Manager is aware of the physical location of a device and applies the appropriate location-specific configuration by selecting the corresponding device pool.