The following image presents a graphical overview of a call flow in a typical Avaya AES environment:

This configuration, with IVR behind the PBX/ACD, implies that the voice call will travel through the Public Phone Network (PSTN) into a PBX/ACD and be passed through to an IVR, which is connected to that PBX/ACD.

Call flow overview

For this scenario, a call moves through the system as shown in the diagram above. The relevant steps in the call flow are numbered and corresponded to the following steps. Some steps include events that occur simultaneously in different parts of the system. In the diagram, the steps for these events have the same number. For example, step 6 appears several times in the diagram. The call flow consists of the following steps:

1. The call comes into the PBX/ACD from the PSTN.
2. The call comes into the Avaya Communications Manager (ACM) PBX from the PSTN.
3. As soon as the call arrives at the PBX/ACD, it is routed to the IVR (also called a VRU).
4. As soon as the call arrives at the PBX, it is routed to the IVR (also called a VRU).
5. Caller identification, such as account number, is gathered in the IVR. The caller proceeds with automated IVR inquiries, such as account balance. This information is typically obtained from various back-end systems or databases.
6. When the caller chooses to speak with a CSR, the IVR passes information about the call in progress to the Avaya ACD. This is commonly known as attaching data to the call. Typically, the information sent by the IVR includes:
   • Caller identification such as Account Number.
   • Indication of what the caller was doing when he “opted out” (for example, a Balance Inquiry). This is commonly referred to as “last action.”
   • Verify flag indicating that the caller successfully provided security information, such as a PIN number, to the IVR
   • Any other information that the IVR has to use in a call routing decision. For example, if the IVR menu includes an alternate language selection, it would include the customer’s choice of language.
7. When the caller chooses to speak with a CSR, the IVR passes information about the call in progress to the Avaya ACM PBX and/or AACC. This is commonly known as attaching data to the call. Typically, the information sent by the IVR includes:
   • Caller identification such as Account Number.
   • Indication of what the caller was doing when he “opted out” (for example, a Balance Inquiry). This is commonly referred to as “last action.”
   • Verify flag indicating that the caller successfully provided security information, such as a PIN number, to the IVR
   • Any other information that the IVR has to use in a call routing decision. For example, if the IVR menu includes an alternate language selection, it would include the customer’s choice of language.
8. The call arrives at the ACD and is routed to a queue, where it waits for an available Customer Service Representative (CSR).
9. When a CSR becomes available, the PBX/ACD connects the call to the CSR. At the same time, the PBX/ACD sends a message through the Avaya AES Server to the Pega Call CTI Link Engine indicating that the call was connected. This message is forwarded for processing to Pega Call rules within Pega Platform. The message includes the PBX/ACD Call ID and the extension of the CSR where the call is being answered.
10. At the desktop, the CSR is logged into the Pega Call. When the appropriate message is received, the desktop works with Pega Platform to generate and display a screenpop with information about the call. The screen pop is displayed at the workstation as a separate window alerting the CSR to the new call. Clicking appropriate buttons in the screen-pop window allows the CSR to begin servicing the call.