This chapter explains the functionality and limitations of VoLTE services that you create and manage on an Oracle Communications Evolved Communications Application Server (OCECAS) implementation.
You use the Session Design Center graphical user interface (GUI) to create the control flows that define the multimedia services that you sell to subscribes, and the change sets that you use to manage changes to your OCECAS implementation.
See ”Working with Session Design Center” in Evolved Communications Application Server System Administrator's Guide for details.
Enhanced Service centralization and continuity application server (SCC-AS) is an LTE functionality that allows you to transition a voice call from a packet-switched domain to a legacy circuit-switched domain. This functionality allows you to offer VoLTE capabilities while using networks that also includes circuit-switched coverage. OCECAS supports the SRVCC procedure for handover from packet-switched to circuit-switched networks. The handover requires access and transfer control function (ATCF) and access and transfer gateway (ATGW) functionality. This is specified in the 3GPP Release 10 specification for SRVCC, and most parts of the 3GPP Release 12 specification.
OCECAS provides this functionality in conjunction with Oracle Communications Session Border Controller (Session Border Controller). Session Border Controller acts as the ATCF and ATGW required for SRVCC. Session Border Controller is a different Oracle product that you purchase separately.
OCECAS itself acts as the service centralization and continuity application server (SCC-AS). It also provides home network anchoring, and terminating access domain selection (T-ADS).
OCECAS provides these tools in a drag-and-drop environment that you use to create VoLTE services:
Make control flow decisions based on:
Date and time
Geographic location
Data in data stores
SIP message headers
Session context or call state
Interact with other systems, including:
Media servers (JSR 309)
Charging systems (using Diameter Ro and Gy)
Messaging gateways (using SOAP or JSON)
Enterprise and Middleware (using SOAP, JSON, JMX, and SNMP traps)
Perform Actions, including:
Manipulating the session state (end session or participant, hold participant, forward session, or add participant)
Early media and pre-call, in-call, or post-call announcements
Call hunting, call forwarding, and call barring
Using location services
Using cross-session context look-up
Using a charging trigger function
Using custom operations, such as raising alarms and branching on statistics
Execute other session logic
Add responses to actions:
Manage call failure
Wait for and act on an event
Store information for later use
You create control flows in the Session Design Center UI to use these business logic features.
The supplementary services listed in the IR.92 IMS Profile for voice and SMS specification define the service capabilities required to continue a multimedia call that originated in a VoLTE network. Essentially, OCECAS becomes the SIP Back-to-back User Agent (B2BUA) for the call.
OCECAS supports these supplementary services:
Anonymous Communication Rejection (ACR) (3GPP 24.611)
Originating Identification Presentation (OIP) (3GPP TS 24.607)
Terminating Identification Presentation (TIP) (3GPP TS 24.608)
Originating Identification Restriction (OIR) (3GPP TS 24.607)
Terminating Identification Restriction (TIR) (3GPP TS 24.608)
Communication Forwarding Unconditional (CFU) (3GPP TS 24.604)
Communication Forwarding on not Logged in (CFNL) (3GPP TS 24.604)
Communication Forwarding on Busy (CFB) (3GPP TS 24.604)
Communication Forwarding on not Reachable (CFNLc) (3GPP TS 24.604)
Communication Forwarding on no Reply (3GPP TS 24.604)
Incoming Call Barring of (ICB) (3GPP TS 24.611)
Outgoing Call Barring (OCB) (3GPP TS 24.611)
Barring of Outgoing International Calls (BOIC) (3GPP TS 24.661)
Barring of International Calls - ex Home Country (BOIC-HC) (3GPP TS 24.611)
Barring of Incoming Calls - When Roaming (BIC-Roam) (3GPP TS 24.611)
Communication Hold (CH) (3GPP TS 24.610)
Ad-hoc Conferencing (3GPP TS 24.605)