- Chapter Objectives
- Issues with Devices Roaming Between Sites
- Device Mobility Overview
- Device Mobility Configuration Elements
- Device Mobility Operation
- Device Mobility Configuration
- Summary
- References
- Review Questions
Device Mobility Configuration Elements
Table 11-2 lists the Device Mobility-related configuration elements and describes their functions. The newly introduced elements are Device Mobility Info (DMI), Physical Location (PL), and Device Mobility Group (DMG).
Table 11-2. Device Configuration Element Functions
Configuration Element Name |
Configuration Element Function |
Device Pool (DP) |
Defines a set of common characteristics for devices. The device pool contains only device- and location-related information. One device pool has to be assigned to each device. |
Device Mobility Info (DMI) |
Specifies an IP subnet and associates it with one or more device pools. DMIs can be associated with one device pool. |
Physical Location (PL) |
A tag assigned to one or more device pools. It is used to identify whether a device is roaming within a physical location or between physical locations. |
Device Mobility Group (DMG) |
A tag assigned to one or more device pools. It is used to identify whether a device is roaming within a Device Mobility Group or between Device Mobility Groups. |
The DMI is configured with a name and an IP subnet and is associated with one or more device pools. Multiple DMIs can be associated with the same device pool.
The Physical Location and the Device Mobility Group are just tags. They are configured with a name only and do not include any other configuration settings. Both are nonmandatory device pool configuration parameters. Therefore, at the device pool you can choose no physical location or one physical location and one or no Device Mobility Group. They are used to determine whether two device pools are at the same physical location and/or in the same Device Mobility Group.
The Relationship Between Device Mobility Configuration Elements
Figure 11-3 shows how the different Device Mobility configuration elements relate to each other.
Figure 11-3 Relationship Between Device Mobility Configuration Elements
The figure shows five DMIs for three physical locations—San Jose, New York, and London. They are configured as follows:
- SJ1_dmi: The IP subnet of this Device Mobility Info is 10.1.1.0/24. This DMI is used at Building A of the San Jose campus and is associated with DP SJ_A_dp.
- SJ2_dmi: The IP subnet of this DMI is 10.1.2.0/24. This DMI is used at Building B1 of the San Jose campus and is associated with device pool SJ_B1_dp.
- SJ3_dmi: The IP subnet of this DMI is 10.1.3.0/24. Like SJ2_dmi, this DMI is used at Building B1, which is associated with device pool SJ_B1_dp, but it is also used at Building B2 and is associated with device pool SJ_B2_dp.
- NY_dmi: The IP subnet of this DMI is 10.3.1.0/24. This DMI is used at the New York campus and is associated with device pool NY_dp.
- LON_dmi: The IP subnet of this DMI is 10.10.1.0/24. This DMI is used at the London campus and is associated with device pool LON_dp.
Device pools SJ_A_dp, SJ_B1_dp, and SJ_B2_dp are all configured with the same physical location (SJ_pl) because they are all used for devices located at the San Jose campus.
Device pool NY_dp, serving the New York campus, is configured with physical location NY_pl. Device pool LON_dp, serving the London campus, is configured with physical location LON_pl.
All device pools that are assigned with a U.S. physical location (that is, SJ_A_dp, SJ_B1_dp, SJ_B2_dp, and NY_dp) are configured with Device Mobility Group US_dmg. This setting means that all U.S. device pools are in the same Device Mobility Group. The London campus is in a different DMG: GB_dmg.
In summary, the U.S. Device Mobility Group consists of two physical locations: San Jose and New York. At San Jose, IP subnets 10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24 are used; New York uses IP subnet 10.3.1.0/24, and London is configured with IP subnet 10.10.1.0/24. Device Mobility Groups are used to recognize differences in dial patterns in different geographic locations.
Based on the IP address of an IP Phone, CUCM can determine one or more associated device pools and the physical location and Device Mobility Group of the device pool or pools. If an IP Phone uses an IP address of IP subnet 10.1.3.0/24, the device pool has two candidates. However, in this example, the physical location and Device Mobility Group are the same for these two device pools.