What is the difference between Partition and Calling Search Space?

--> Partitions and Calling Search Spaces are primarily used to implement call of control in CUCM.

--> Partition and  Calling Search Spaces are used to block or allow users making certain calls.

--> A partition is a group of Directory numbers with same accessibility.

--> Any dialable number can be added in the partition.

--> By default all numbers get <none> partition.

--> Calling Search Space is ordered list of partitions that can call each other.

--> All the devices by default get <none> Calling Search Space.

--> It is not possible to make changes in <none> CSS.

--> By default at the end of each CSS there is a <none> partition, which is invisible.

--> With the help of following the logic you can easily understand what is Calling Search Space and Partition.

i) Partition = Where you are

ii) Calling Search Space=Where you can call

--> When you attempt to make a call from an IP Phone, CUCM checks 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 Example, we can implement following by using Partitions and Calling Search Space,

i) IP Phones in Sales department can dial anywhere within the company and all local area calls, but not international calls.

2. IP Phones in IT department can place calls during normal business hours, but not at other times.

--> Partition can be associated with DN, Route Pattern, Hunt Pilot, etc.

--> CSS can be associated with DN, Phone, Gateway, etc.

--> IP Phones in the same Partition does not mean that they can call each other until they are in the same Calling Search Space.

--> IP Phones Calling to the destination depends upon Calling Search Space, not its Partition.

Ref: Cisco.com

Md.Kareemoddin

CCIE # 54759