Partitions and CSS: Implementing Calling Restrictions + Best Practices

Why wait years to discover some of the CUCM dial plan best practices through trial and error when you can learn them right now? In this Nugget, Jeremy talks through simple and salable methods you can use to design Partitions and CSSs the right way from the onset.


Create a partition containing ALL dialable numbers

Create a partition containing BLOCKED numbers

In the CSS, place the blocked partition before the dialable partition

Partition: BLOCKED – 9.1900!, 9.1978!, 9.011!
Partition PSTN – 9.[2-9]XXXXXX, etc….

INT_CSS – BLOCKED and PSTN Partitions

A CSS can be assigned to a LINE and a DEVICE, creating one big CSS. LINE is checked 1st then down to the DEVICE.

Apply BLOCKED CSS to the LINE itself, then PSTN access on the DEVICE. Similar concept to an access list!

Create your CSS based on calling privileges, not individuals. Then assign the appropriate CSS to each set of lines + phones.

Jeremy recommends a book called ‘Cisco CallManager Best Practices’.