CSS and Partition

Partition:

Partitions can be seen as a collection of route patterns.

Directory numbers, route patterns, and translation patterns can all belong to specific partitions.

CSS(Calling Search Space):

CSS’es are an ordered list of route partitions and they determine which partitions calling devices must search when they attempt to complete a call. In order to reach a certain destination, the called party’s partition must belong to the calling party’s CSS.

When you attempt to make a call, Cisco CallManager looks into the CSS of the calling party and checks if the called party belongs to a partition within the CSS. If it does, the call is placed or the translation pattern is executed. If not, the call is rejected or the translation pattern is ignored.

For a better understanding, providing a example below.

In an organisation, we are having three teams, say IT Team, Business Team and Internal Team and we are having calling condition as below.

1. IT Team can make calls to Business and Internal Team.
2. Business team should only call to internal Team.
3. Internal team should not call any other teams.

Partition Needs to be created:

1. IT_PT
2. Busi_PT
3. Inter_PT

CSS Needs to be created:

1. IT_CSS
2. Busi_CSS
3. Inter_CSS

CSS and PT Mapping:

1. IT CSS should contain IT_PT, Busi_PT and Inter_PT
2. Busi_CSS should contain Inter_PT and Busi_PT
3. Inter_CSS should contain only Inter_PT

Mapping of CSS, PT for Teams.

1. All the IT Phones should be mapped with Partition as IT_PT and CSS as IT_CSS
2. All the Business Phones should be mapped with Partition as Busi_PT and CSS as Busi_CSS
3. All the Internal Phones should be mapped with Partition as Inter_PT and CSS as Inter_CSS
   

Sample CSS, Partition creation and mapping

Partition Creation:

Navigate to Call Routing –> Class of Control –> Partition

Add new -> Give a name and click on save.

CSS Creation and partition mapping:

Navigate to Call Routing –> Class of Control –> calling search space.

Add New-> GIve name, Description and associate the partition in it-> save

Mapping of partition and CSS in phones:

Navigate to line page of the phone->Select partition and CSS–> Save