6.4 Call Handlers & Directory Handlers

6.4 Call Handlers & Directory Handlers

Cisco Unity Connection (CUC) provides rich Interactive Voice Response (IVR), automated attendant, and organizational directory capabilities. By orchestrating System Call Handlers, Directory Handlers, and Interview Handlers, organizations can route inbound callers efficiently, publish self-service dial-by-name directories, and gather structured responses without requiring human operator intervention.

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1. System Call Handlers & Automated Attendant Architecture

A System Call Handler is the foundational building block of an automated attendant. It greets external or internal callers, plays recorded audio menus, collects Dual-Tone Multi-Frequency (DTMF) touch-tone keypresses, and branches callers to destinations such as departments, specific users, sub-menus, or external phone numbers.

+-----------------------------------------------------------------------------------+
|                     SYSTEM CALL HANDLER INTERNAL ARCHITECTURE                     |
|                                                                                   |
|  CALL HANDLER: 'Main-Company-Attendant'                                           |
|  +-----------------------------------------------------------------------------+  |
|  |  1. GREETINGS ENGINE                                                        |  |
|  |     - Evaluates active schedules (Standard, Closed, Holiday, Alternate)     |  |
|  |     - Plays: "Thank you for calling Acme Corp. For Sales, press 1..."       |  |
|  |                                                                             |  |
|  |  2. CALLER INPUT TABLE (DTMF 0-9, *, #)                                     |  |
|  |     - Key 1 -> Route to Call Handler: 'Sales-Menu'                          |  |
|  |     - Key 2 -> Route to Call Handler: 'Support-Menu'                        |  |
|  |     - Key 8 -> Route to Directory Handler: 'Corporate-Dial-By-Name'        |  |
|  |     - Key 0 -> Transfer to Alternate Contact: Operator Ext 1000            |  |
|  |                                                                             |  |
|  |  3. AFTER GREETING ACTION                                                   |  |
|  |     - Action taken if caller enters no DTMF digits: Replay Menu or Transfer |  |
|  +-----------------------------------------------------------------------------+  |
+-----------------------------------------------------------------------------------+

Primary Functional Components of a Call Handler

1. Greetings: The recorded audio prompts played to callers. Multiple greeting types exist to match business schedules (e.g., standard business hours, evening closed hours, or holiday closures).
2. Caller Input: A configurable mapping table that assigns discrete routing actions to dial-pad digits 0 through 9, * (star), and # (pound).
3. Transfer Rules: Determines whether CUC attempts to transfer the caller to an extension (and whether it performs a blind transfer, supervised transfer, or sends the caller straight to greeting/recording).
4. Message Settings: Configures whether the call handler acts as a voice mailbox to record messages left by callers (e.g., an after-hours general inquiries box), and designates which user or distribution list receives the recordings.

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2. Inbound Call Routing Rules: Direct vs. Forwarded

When a call arrives at CUC across a SIP trunk, the system must evaluate its internal Call Routing Rules engine to determine which Call Handler or User Mailbox should answer. CUC divides inbound traffic into two distinct routing rule tables:

                         INCOMING SIP CALL
                                |
                                v
             Does the SIP INVITE contain redirection
             data (a Diversion or History-Info header)?
                                |
               +----------------+----------------+
               | NO                              | YES
               v                                 v
     [ DIRECT ROUTING RULES ]          [ FORWARDED ROUTING RULES ]
     Top-Down Rule Evaluation          Top-Down Rule Evaluation
     1. Attempt Sign-In                1. Attempt Forward
        (Caller ID = user extension)      (Forwarding ext -> its greeting)
     2. Opening Greeting               2. Opening Greeting
        (Default call handler)            (Default call handler)

1. Direct Routing Rules

Direct routing rules evaluate calls that arrive directly at CUC without prior forwarding (e.g., a caller dials the Voice Mail Pilot number directly, or an outside customer dials the main corporate IVR pilot number):

• Default Rule 1: Attempt Sign-In: If the calling number matches a user's primary or alternate extension, CUC sends the caller to the sign-in conversation (PIN prompt).
• Default Rule 2: Opening Greeting: Every other direct call goes to the Opening Greeting call handler (the default call handler), which acts as the auto-attendant.

2. Forwarded Routing Rules

Forwarded routing rules evaluate calls that arrive indirectly via call forwarding (CFB, CFNA, CFA) containing an RFC 5806 Diversion header:

• Default Rule 1: Attempt Forward: Sends the call to the greeting of the user or call handler whose extension forwarded the call (taken from the Diversion header), so the caller can leave a message.
• Default Rule 2: Opening Greeting: If the forwarding extension matches no user or call handler, the call goes to the Opening Greeting.

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3. Greeting Types & Hierarchical Precedence

Every call handler and user mailbox has seven greetings: Alternate, Busy, Internal, Holiday, Closed, Standard, and Error. The first six follow a fixed precedence; the Error greeting plays when a caller enters an invalid key or extension:

+-----------------------------------------------------------------------------------+
|                         GREETING PRECEDENCE HIERARCHY                             |
|                                                                                   |
|    HIGHEST PRECEDENCE                                                             |
|    [ 1. ALTERNATE GREETING ]  --> Overrides ALL other greetings when enabled      |
|               |                   (Used for vacations, closures, emergencies)     |
|               v                                                                   |
|    [ 2. BUSY GREETING ]       --> Plays when the extension is busy (CFB)          |
|               |                                                                   |
|               v                                                                   |
|    [ 3. INTERNAL GREETING ]   --> Plays only to callers who are users             |
|               |                                                                   |
|               v                                                                   |
|    [ 4. HOLIDAY GREETING ]    --> Plays on dates in the holiday schedule          |
|               |                                                                   |
|               v                                                                   |
|    [ 5. CLOSED GREETING ]     --> Plays during closed (nonbusiness) hours         |
|               |                                                                   |
|               v                                                                   |
|    [ 6. STANDARD GREETING ]   --> Default greeting when nothing above applies     |
|    LOWEST PRECEDENCE                                                              |
+-----------------------------------------------------------------------------------+

Detailed Greeting Behaviors

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4. Caller Input & Key Mapping Actions

Within a System Call Handler, the Caller Input menu maps telephone dial-pad keys (0 through 9, *, #) to specific programmatic behaviors. Each key can be assigned one of the following actions:

• Ignore: The keypress is ignored; CUC continues playing the greeting.
• Hang Up: Immediately plays a disconnect tone or polite sign-off and terminates the call.
• Restart Greeting: Stops current playback and restarts the call handler greeting from the beginning.
• Route to Call Handler: Transitions the caller to another nested Call Handler menu (e.g., Key 1 branches to the Sales-Menu Call Handler).
• Transfer to Alternate Contact Number: Initiates a telephony transfer to an external number or internal extension (subject to Restriction Tables).
• Take Message: Directs the caller immediately into the recording prompt for a designated user or call handler.
• Route to Directory Handler: Transitions the caller into a dial-by-name directory search.

Inter-Digit Timers & 'Wait for Additional Digits'

When an administrator maps single-digit keys (e.g., Key 1 for Sales), callers who know their party's internal extension (e.g., 1042) might dial 1 followed immediately by 042.

• Each key has a Lock Key to Prevent Extension Dialing option. A locked key runs its action immediately, so callers cannot dial extensions that begin with that digit.
• An unlocked key makes CUC wait for more digits, using the call handler's Wait for Additional Digits time (1,500 ms by default). If more digits arrive, CUC treats the entry as an extension; otherwise it runs the single-key action.

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5. Directory Handlers & Search Scopes

A Directory Handler enables callers to search for employees by name and dial their extensions directly.

+-----------------------------------------------------------------------------------+
|                         DIRECTORY HANDLER SEARCH ENGINES                          |
|                                                                                   |
|  TYPE 1: PHONE DIRECTORY HANDLER (TOUCH-TONE DTMF)                                |
|  - Caller uses dial-pad letters (e.g., presses 7-6-4-8-4 for 'SMITH')             |
|  - Supported Search Orders:                                                       |
|    1. Last Name, First Name                                                       |
|    2. First Name, Last Name                                                       |
|                                                                                   |
|  TYPE 2: VOICE-ENABLED DIRECTORY HANDLER (SPEECH RECOGNITION / ASR)               |
|  - Uses Automatic Speech Recognition (voice recognition)                          |
|  - Caller speaks the employee name naturally: "Connect me to Alice Smith"         |
|  - Requires ASR server sizing and speech license allocation                       |
+-----------------------------------------------------------------------------------+

Directory Search Scopes

To enforce privacy and administrative boundaries, Directory Handlers restrict search results using Search Spaces:

• Directory Search Space: Defines which subscriber partitions are visible to the caller.
• In a multi-tenant or multi-campus environment, Campus A callers can be restricted to searching only Campus A employees, preventing external callers from viewing or transferring to executive lines or secure facilities.

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6. Interview Handlers

An Interview Handler is a specialized automated attendant tool designed to conduct structured audio question-and-answer interviews over the telephone without live staff involvement:

Caller Dials Interview Number
           |
           v
+-----------------------------------------------------------------------------------+
|                    INTERVIEW HANDLER RECORDING SEQUENCE                           |
|                                                                                   |
|  Prompt 1: "Please state your full name and employee ID."                         |
|  [ System Records Caller Response ] -> Inter-question tone                        |
|                                                                                   |
|  Prompt 2: "Please describe the equipment issue and room number."                 |
|  [ System Records Caller Response ] -> Inter-question tone                        |
|                                                                                   |
|  Prompt 3: "Provide a callback telephone number."                                 |
|  [ System Records Caller Response ] -> Caller hangs up or presses '#'             |
+-----------------------------------------------------------------------------------+
           |
           v
All responses stitched into a SINGLE audio voice message
           |
           v
Delivered to: [ IT-Helpdesk-Mailbox ] or Distribution List

Key Interview Handler Mechanics

• Sequential Questions: CUC plays Question 1, records the response (up to a configured maximum duration), plays a confirmation tone, and proceeds to Question 2 (supports up to 20 questions per handler).
• Response Compilation: Unlike multiple disjointed voice messages, CUC concatenates all recorded answers into a single, unified voice message.
• Dispatch Recipient: The compiled message is automatically deposited into a designated subscriber mailbox or System Distribution List (e.g., Job-Applicants-Mailbox or Facilities-Work-Orders).