Evolve Call Intercept Service¶
Evolve ® Call Intercept (CIN) service is an Advanced Intelligent Network (AIN) service for both residential and commercial customers that provides a simple solution for managing unwanted calls. CIN automatically intercepts and screens all incoming calls. With calls from restricted, blocked, or unknown numbers, the called party can request that the calling party identify themselves prior to answering the call. The caller’s identity is recorded and played back to the called party, and the called party can then use that identification information to decide whether they want to answer the call.
CIN includes highly customizable VIP (allowed) numbers and blocked numbers lists and allows for call treatment customization if the calling party does not match either of these lists. A customer can choose to have the caller identify themselves and determine the call route further or even stop all other calls.
VIP and Blocked Number Lists¶
CIN allows users to define a list of caller IDs to always allow and connect the call. Calls from caller IDs not matching this VIP number list or on the blocked number list will be blocked, sent to an announcement, and then either terminated or sent to voice mail.
These lists can be updated through the web-based user interface, API, or an interactive voice response (IVR) that the user can call into. Additionally, users can create an override PIN that can be used when calling in when CIN service is active to override the defined VIP number list and connect the call.
Separation of Roles¶
CIN is designed for multi-tenancy with three distinct roles. These roles are Platform Owners, Service Providers, and Subscribers. Each of these roles have their own responsibilities and functions.
Platform Owners
The Platform Owner is the entity that deploys the network which runs CIN. The Platform Owner is responsible for defining physical egress routes and other network specifics. Additionally, Platform Owners create and define Service Providers.
Service Providers
A Service Provider is the entity that offers CIN as a service to Subscribers. The Service Provider is responsible for defining the call treatment sequence, allocating numbers to Subscribers, and determining the amount of customization for Subscribers.
Subscribers
Subscribers are the individuals or business entities that subscribe to the CIN service. Subscribers’ calls are screened by the number lists defined by Service Providers. Subscribers may be given access to their own numbers and can edit number lists as well.
Signaling¶
CIN is deployed in the network and is designed to handle AIN Termination_Attempt and SIP INVITE signals to process call screening treatment prior to the call terminating.
The rest of this chapter details the specific call flow of various call treatments.
Note
Wireshark traces of a call flow can be viewed by clicking the link provided below the diagram.
AIN Queries and Responses¶
AIN Termination_Attempt
The following diagram shows the message exchange when Termination_Attempt is received from a number that is on the VIP Numbers list.
The following diagram shows the message exchange when Termination_Attempt is received from a number that is not on the Blocked Numbers list.
The following diagram shows the message exchange when Termination_Attempt is received from a number that is not a CIN subscriber.
The following diagram shows the message exchange when Termination_Attempt is received from an unknown number. CIN responds with a Forward_Call so the originating switch sends the call to a switch that is capable of SIP calls for continued routing.
SIP Call Treatments¶
The following SIP Call diagrams can be from any SIP call, including calls that were IN originating and received the Forward_Call response from CIN.
Note
When the called party does not answer and the call is forwarded to voice mail, there will be a delay and then the calling party will hear a recording that the called party is not available and the call will be ended.
The following diagram shows the message exchange when a SIP call is received from a number that is on the VIP Numbers list.
The following diagram shows the message exchange when a SIP call is received from a number that is on the Blocked Numbers list and the Reject with Media setting is turned off.
The following diagram shows the message exchange when a SIP call is received from a number that is on the Blocked Numbers list and the Reject with Media setting is turned on.
The following diagram shows the message exchange when a SIP call is made and the override PIN is entered.
The following diagram shows the message exchange when a SIP call is accepted by the called party.
The following diagram shows the message exchange when a SIP call is rejected by the called party.
The following diagram shows the message exchange when a SIP call is rejected by the called party and sent to voice mail.
The following diagram shows the message exchange when a SIP call is received from a number that is not a CIN subscriber.
