Traditional PBXs typically allow the configuration of multiple
appearances of the same Dialed Number (DN) on different lines of a single
phone. For example, if a user extension is 1002, they might have three or four
buttons on their phone that all correspond to extension 1002. Cisco CallManager
3.0 does not have a quick and easy way to accomplish this. Until the ability to
have more than two calls on a single line appearance is available, this
document shows how to use Partitions and Calling Search Spaces to configure
multiple lines on one phone with the same DN. It is assumed that the user wants
all incoming calls to start on line 1 and forward to subsequent lines if line 1
There are no specific requirements for this document.
This document is not restricted to specific software and hardware
Technical Tips Conventions for more information on document
In order to do this, you are forced to use Partitions and Calling
Search Spaces. First you must create partitions equal to the number of maximum
number of lines you would like on any phone. If you use the Cisco 7960 IP
Phone, the maximum is six. It is probably best to configure up to six lines
just in case.
Create six partitions named 'Line1' through 'Line 6'. You can also
choose to create other partitions to limit outbound dialing as well, but these
topics are not discussed in this document.
Use the Route Plan > Partition
menu in the Cisco CallManager administration window to create the partitions.
Enter the name of the partition and click Insert. Once
completed, your partitions should look similar to this:
You need to create five Calling Search Spaces to handle the forwarding
between lines. Each Calling Search Space only has one partition in it. The sole
purpose of these Calling Search Spaces is to forward a call from one line to
For example, create a Calling Search Space called 'Line1to2' which only
contains the 'Line 2' Partition. Then create a Calling Search Space called
'Line2to3' which only contains the 'Line 3' Partition. Continue to do this
until you have five Calling Search Spaces as this table shows:
Calling Search Space Name
Partitions in the Calling Search Space
You also need to create one more Calling Search Space to allow devices
to call each other. In this example, the Calling Search Space is called 'Phones
Only'. This Calling Search Space only contains the 'Line 1' Partition. If you
create other Calling Search Spaces for Local, LD, and/or international dialing,
be sure to include the Line 1 partition if you want those users to be able to
call other IP phones in your cluster. The Line 2 through Line 6 Partitions
should not appear in any other Calling Search Spaces.
Once you have created the Partitions and Calling Search Spaces, you can
proceed to configure your phones. With the configuration in this document, you
can now have up to six lines on a phone with the same DN on all of them. For
example, if you want to have a phone with extension 15644 on three lines, first
configure a button template that has three lines, then perform the tasks in
this section. This example assumes the phone is already configured in Cisco
CallManager and the correct button template is selected.
The phone that is configured eventually looks like this:
The first line should be configured as this window shows:
In this example, 15678 is the Voicemail pilot number, therefore an
appropriate Calling Search Space is required to be able to access that pilot
number. In our example, the 'Int' Calling Search Space contains all DNs
internal to the Cisco CallManager. The important thing to note here is that the
Partition for this line is 'Line 1' and the Calling Search Space for Forward
Busy is set to 'Line1to2'. All other parameters can be set to match your
The second line is configured as this window shows:
The important thing to note for the second line is that the Partition
for this line is 'Line 2' and the Calling Search Space for Forward Busy is set
to 'Line2to3'. All other parameters can be set to match your environment.
The third line is configured as this window shows:
This line is configured in the 'Line 3' Partition. However the
forwarding information goes to voicemail, since this is the last line. If you
want more lines, this would have the 'Line3to4' Calling Search Space for
Forward busy and so on.
Note: In order to make this phone able to call other phones, you must
configure a Calling Search Space that has access to the 'Line 1' partition
either on the three lines in this section, or just on the phone where these
lines are configured.