Evolve Custom Redirect Service¶
Evolve ® Custom Redirect service (CRS) is a one-step redirect solution that offers a reliable way to forward groups of numbers quickly and easily. Calls may be redirected at the customer’s request, at all times, or on a time of day basis.
CRS is a group-based call routing service which allows a subscriber to redirect incoming calls as needed without placing an order or redirecting each number individually. A subscriber can redirect as many numbers or groups as they need with CRS following the call plan to redirect that was last changed.
CRS includes a ready-to-use web-based user interface for easy access to modify number forwarding destinations and other functionality and different layouts for the various user roles to edit and prioritize the features of CRS.
The CRS API is also available to allow developers to programmatically integrate CRS with network elements and systems and gives additional flexibility with how CRS is offered to customers.
Groups and Supergroups¶
A unique feature of CRS is the creation of Groups and Supergroups. Customers can build groups, which are simply collections of routable numbers, and supergroups, which are collections of groups. Numbers can also belong to multiple groups and there is no limit on how many numbers can be redirected at once. Call plans are then created and associated with groups to determine how the calls within the group are routed.
Separation of Roles¶
CRS 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 CRS. 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 CRS as a service to Subscribers. The Service Provider is responsible for defining numbers and associated routing behavior, allocating numbers to Subscribers, and determining the amount of customization for Subscribers.
Subscribers
Subscribers are the individuals or business entities that subscribe to CRS. Subscribers’ calls are routed based on the numbers and routing behavior designated to them by Service Providers. Subscribers may be given access to edit the forwarding options for their numbers.
Call Processing¶
When CRS receives an incoming call, the database is checked to verify that the called number is associated with CRS. If the called number is not in the CRS database or CRS is not associated with it, the application responds with the configured No-Route Behavior.
If the called number is in the database, the application then steps through the routing engine. The called number will have one or more groups associated with it. If the number is not part of a group, the call will be forwarded to the default destination. If the number is part of one or more groups, the routing engine will see which group was last activated and follow the call plan associated with that group.
Signaling¶
CRS is deployed in the network and is designed to handle AIN and SIP signals to process call routing behavior.
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.
SIP Call Treatments¶
SIP REDIRECT Method
The following diagram shows the message exchange when the SIP 302 REDIRECT connection type is selected.
SIP Attended Transfer (REFER Method)
The following diagram shows the message exchange when the Attended Transfer connection type is selected.
SIP B2BUA
The following diagram shows the message exchange when the SIP B2BUA connection type is selected.
SIP Admin (IVR)
The following diagram shows the message exchange when calling the administrative IVR.
The following diagram shows the RTP exchange when calling the administrative IVR.
AIN Queries and Responses¶
AIN Info_Collected
The following diagram shows the message exchange when Info_Collected is received.
AIN Info_Analyzed
The following diagram shows the message exchange when Info_Analyzed is received.
