Enhanced Call Forwarding¶
As the ultimate forwarding application, Evolve ® Enhanced Call Forwarding (ECF) service takes any called number and forwards it to any destination.
ECF 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 ECF.
The ECF API is also available to allow developers to programmatically integrate ECF with network elements and systems and gives additional flexibility with how ECF is offered to customers.
Call Forwarding¶
Call forwarding has been a feature for a long time that many subscribers have come to depend on. Today, many subscribers have multiple places and devices where they can receive calls, and sending calls to voice mail is not always a convenient or available option. Therefore, there is value in having all calls or only certain calls reach subscribers at home, at work, and on the go.
One of the major problems with call forwarding is usability and how easy, dynamic, and flexible call forwarding features are to define. ECF is a solution to this problem that will allow subscribers to take full advantage of the idea of never missing a single call.
As a service, ECF simply redirects a phone call to another destination where, ideally, the called party is actually available to answer, completing the forwarded call. ECF offers this basic call forwarding behavior, both with and without an expiration date.
ECF starts with a list of subscribers who have enabled the feature, and the entire feature set is implemented by adding one or more routing rules to each number that is forwarded.
It is common to supplement basic call forwarding by applying certain conditions to these routing rules. For example, an applied condition may create a time-of-day routing rule that automatically forwards calls made to a subscriber’s office phone number to their cell phone number outside of normal office hours. This condition can be customized even further to only forward calls made from specific numbers.
Speed Call Numbers¶
A unique feature of ECF is the list of default speed call numbers that can be set up for easy call forwarding. These speed call numbers can be selected via the IVR or web UI for customers to quickly begin forwarding to their most commonly used numbers.
Call Screening¶
There may be some callers that the subscriber will want to always forward regardless of the current conditions applied to their routing rules. In this case, ECF allows subscribers to create a Caller Acceptance List, which is a list of phone numbers that will always be automatically forwarded to a subscriber’s phone.
Separation of Roles¶
ECF 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 ECF. 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 ECF as a service to Subscribers. The Service Provider is responsible for defining numbers and associated forwarding behavior, allocating numbers to Subscribers, and determining the amount of customization for Subscribers.
Subscribers
Subscribers are the individuals or business entities that subscribe to ECF. Subscribers’ calls are forwarded 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 ECF receives an incoming call, the database is checked to verify that the called number is associated with ECF. If the called number is not in the ECF database or ECF 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 forward numbers associated with it. If the forward number is active, the appropriate destination is provided in the response message and the call will be forwarded to the destination. If there is no active forward number, the application responds with the configured No-Route Behavior.
Signaling¶
ECF 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.
