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Collaboration, Voice & AV · Advanced

Line/Device Calling Search Space Approach

A CUCM design that uses the device CSS for site-specific routing and the line CSS to block destinations a user may not reach.

Definition

In this approach the device CSS contains partitions with site PSTN route patterns, while the line CSS contains partitions with blocking patterns for disallowed destinations such as international numbers. Because line partitions are searched first, a blocking pattern wins ties, enforcing class of service while keeping routing tied to the physical site. This reduces the number of CSSs needed in multisite designs.

Example

A line CSS with a blocking pattern for 9011! prevents international calls while the device CSS routes local calls through the branch gateway.

Exam tip

Expect a question asking which CSS carries blocking patterns: the line CSS.

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