This document provides the configuration steps required to allow an IP
phone that is not a voicemail subscriber to use the voicemail of another IP
phone. This can be used in instances where IP phone A calls IP phone B and IP
phone B does not answer because it is not a voicemail subscriber and you want
the call to be forwarded to the voicemail of IP phone C instead.
Basic knowledge of Cisco Unified CallManager and Cisco Unity
Administration is necessary.
The information in this document is based on Cisco Unity 4.0.
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Refer to the
Technical Tips Conventions for more information on document
You can forward your call to a voicemail box if you are busy or do not
answer. In this case, a message of an extension without voicemail is forwarded
to another extension that has voicemail. This document describes how to
configure Cisco Unity to use the voicemail of another extension.
In this sample configuration, the IP phone without voicemail is Phone
B with extension 4500 and the IP phone with voicemail is Phone C with extension
Complete these steps to configure Cisco Unity to forward a voicemail
message to another extension.
Assign a voicemail profile for IP phone B.
Select Cisco CallManager Administration page
> Device > Phone.
Click on the directory number located on the left side of the
Phone configuration page.
Assign a voicemail profile to the directory number of Phone B
which is not a voicemail subscriber.
Check Forward Busy and Forward No
Answer in order to forward the call to voicemail if Phone B does not
answer or is busy.
Go to the Cisco Unity Web Admin page and click Call
Handlers to create a new call handler.
Click Change to assign an owner to this call
handler. This owner needs to be the subscriber who is to receive the forwarded
Note: The call handler should be assigned to a valid owner. Otherwise
the call transfer fails at the call handler.
Enter the extension number of the non-subscriber in the Extension
Click Call Transfer, select Yes ring the
subscriber at this extension and enter the extension number of the
Select Messages, click Select to
select the message recipient, and choose the subscriber to whom the voicemail
Click Save to save the
Scenario: If phone A does not answer, you need to forward the call to
phone B; if phone B does not answer, the call must go to the voicemail of phone
B. This is not possible since the call rings on phone A first; Cisco Unity
understands that phone A is the owner of the call, so it tries to send the call
to the voicemail of phone A.
If there are only a few users who need such a feature, use this
Go to the configuration of phone B and set phone A as an alternate
extension of phone B. This way, when the call comes and neither phone A nor
phone B answers, the call goes back to the voicemail of phone A. Since phone A
is an alternate extension of phone B, the call goes to the voicemail of phone
B. For more information on the configuration of alternate extensions, refer to
Note: Keep in mind that alternate extensions support up to 9 numbers only,
and the configuration is static. For instance, if phone A sometimes forwards
calls to phone C, it cannot work.
Unity 5.0 supports the option to route calls based on either the first
or last redirected number when a call is forwarded to Cisco Unity.
Call the extension for Phone B and make sure that the voicemail for
Phone C answers the call in order to verify this configuration.
There is currently no troubleshooting procedure available for this