4.4 Directory URI Partitions and CSSs

This topic describes how partitions and CSSs relate to directory URIs.

  • Any partition can be applied to directory URIs that are configured at the directory number page.
  • All end-user-based directory URIs are automatically put into a default partition.
    1. Applies to manually configured end-user-based directory URIs and to end-user-based directory URIs synchronized via LDAP
    2. The name of the partition is Directory URI.
    3. The partition can be renamed, but it cannot be deleted.
    4. The partition can be aliased by any existing partition by setting the Directory URI Alias Partition enterprise parameter.
  • A URI can exist only once in the same partition.
  • The same CSS that is used for numbered calls is also used for URI dialing.

Directory URIs can be assigned to different partitions. Call-routing decisions are the same as with directory numbers.

When a directory URI is provisioned via a local end user or an LDAP end user, then a default partition is applied to the URI. The default partition is created during the Cisco Unified Communications Manager installation and is named Directory URI. This partition cannot be deleted, but it can be renamed.

To allow calls to end-user-based directory URIs, a CSS that includes this partition must be applied to the calling device (gateway, trunk, phone, phone line, and so on).

Instead of changing several CSSs, Cisco Unified Communications Manager allows you to define an alias partition for the Directory URI partition. Set the enterprise parameter that is named Directory URI Alias Partitionto an existing partition that should be used as an alias. By selecting an existing partition as a directory URI alias partition, all CSSs that have access to the selected alias partition will automatically have access to the Directory URI partition as well.

The same CSS is used for directory number-based call routing and directory URI-based call routing. A directory URI and its associated directory number, however, can have different partitions applied.


This concept differs from the implementation of presence-enabled call lists. In presence-enabled call lists, a directory number has only one partition, which is used for call-routing requests and for requests to watch the presence status. The CSS that is used for presence-enabled call lists is configured separately from the CSS for call routing. In addition to the standard CSS, which is used for call routing, there is a subscribe CSS that is configured at the watching phone, which is used to watch the presence status of a directory number.

The routing logic for directory URIs is also identical to the logic for directory numbers. The best matching pattern is used. If there are multiple equally qualified matching patterns, then the order of partitions is used as a tie breaker (with priority given to partitions that are listed first).