Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Cisco Unity Call Flow





This document describes the Cisco Unity's Call Flow.



Understanding Cisco Unity's Call Flow Essentials



Understanding how calls flow through the unified communications systems is very important for system administrators of PA and the voice-messaging system Cisco Unity.


Outside Caller Call Flow



In Cisco Unity, an outside caller is someone who Cisco Unity cannot identify as a Cisco Unity subscriber. Generally, this is a person who is calling in from the outside who wants to reach an individual at a place of business. When a subscriber is busy or away from their phone, Cisco Unity can answer the call and take a message for them. The subscriber can later hear their message either over the phone or by using IBM Lotus Notes, Microsoft Outlook, or Cisco Unity Inbox (depending on the configuration setup of the Cisco Unity system). In addition, if Cisco Unity subscribers call in from a phone other than their defined office extension, Cisco Unity treats those calls as outside callers until they sign in and identify themselves.






Step 1



The outside caller dials a phone number from his mobile phone. The phone number dialed is a Direct Inward Dialing (DID) number that belongs to a Cisco Unity subscriber.



Step 2



The Public System Telephone Network (PSTN) routes the caller to the office communications equipment.



Step 3



The DID number is programmed to ring a phone extension. Based on DID information provided by the PSTN, the business telephone system sends the incoming call to the telephone that it is programmed to connect to that DID number.



Step 4



The telephone rings four times, but the subscriber does not answer the phone because he is busy working on a presentation. The telephone system has been programmed to forward any unanswered calls to voice mail after four rings. The telephone system forwards the outside caller to the voice-mail system.



Step 5



Cisco Unity receives the call and the extension of the subscriber to take a message for. Cisco Unity has a list of subscriber extensions and the e-mail aliases to send messages to. Cisco Unity records a message from the caller, addresses it to the subscriber's alias, and then sends it to the message store server.



Step 6



The message store server receives the message and stores the message for the subscriber.



Step 7



While Cisco Unity is monitoring events in the message store, it notices a new voice-mail message for the subscriber and sends the message waiting indicator (MWI) ON code to the telephone system for the subscriber's extension.



Step 8



The telephone system lights the lamp at the subscriber's telephone set. The telephone now displays an MWI to alert the subscriber of a new message.



NOTE:- If a previous message had been sent to this subscriber, the MWI would have been activated at that time. Therefore, the lamp or indicator remains activated.



Subscriber Call Flow



A Cisco Unity subscriber is a person who has a user account on the Cisco Unity system. Each subscriber account has a Profile page that stores specific information about that subscriber, such as the extension, security code, recorded name, and the e-mail alias to send messages to.





Step 1



The subscriber notices the MWI on her telephone and calls the voice-mail system to retrieve messages.



Step 2



The telephone system directs the call and the caller information (the telephone extension) to the Cisco Unity system.



Step 3



Cisco Unity receives the call and the extension of the telephone from the telephone system. Cisco Unity recognizes the extension from its list of subscribers, and accesses the subscriber's e-mail message store to retrieve the voice message. Cisco Unity asks the subscriber to enter her password. After entering the password, Cisco Unity offers to play the message for the subscriber.



Step 4



The subscriber chooses to listen to the message. Cisco Unity plays it and then offers a menu of actions to take with the message, such as save as new, delete, or forward. The subscriber presses the digit 3 to delete the message. While the subscriber is listening to the message, Cisco Unity sends an MWI OFF code. If the subscriber hangs up while the message is being played or does not press 3, then the MWI turns back on.



Step 5



Cisco Unity verbally confirms to the subscriber that the message is deleted and sends the subscriber's delete message command to the message store server.



Step 6



The message store deletes the message. (The message is either deleted or moved to the deleted items folder, depending on the settings in the subscriber's account.)



Step 7



Cisco Unity sends the MWI OFF code to the telephone system.



Step 8



The telephone system receives the MWI OFF code and turns off the MWI on the phone.



Step 9



The MWI of the telephone is off.



Related Links

Unity Call Flow

Version history
Revision #:
2 of 2
Last update:
‎08-27-2017 11:34 PM
Updated by:
Everyone's tags (3)

Hi Shalu

Well explained ! Thanks for sharing.