1. Essentials Guide
  2. Oracle USM Supporting the IMS Core
  3. Tel-URI Resolution
  4. Actions Based on Lookup Results

Actions Based on Lookup Results

The Oracle Communications Unified Session Manager forwards to the resultant SIP-URI under the following conditions:

  • The SIP-URI is in the Oracle Communications Unified Session Manager cache, in which case the Oracle Communications Unified Session Manager performs terminating services.
  • The SIP-URI is not in the Oracle Communications Unified Session Manager cache, and the Oracle Communications Unified Session Manager is configured to service the returned domain. 
In this case, the Oracle Communications Unified Session Manager performs the following:
    1. The Oracle Communications Unified Session Manager issues an LIR for the SIP-URI.
    2. The Oracle Communications Unified Session Manager forwards the message to the correct S-CSCF.
  • The SIP-URI is not in the Oracle Communications Unified Session Manager cache, and the Oracle Communications Unified Session Manager is not configured to service the returned domain. 
In this case, the Oracle Communications Unified Session Manager performs refers to local policy to forward the message via local policy.

PSTN Breakout Routing

The Oracle Communications Unified Session Manager complies with RFC 4694 for operation with request-URIs that include carrier identification code/route number/number portability database dip indicator (cic/rn/npdi) information and routes those requests according to the rn information. The routing process includes utilization of local policy configured to break the request out of the home network via gateways such as a BGCF.

The Oracle Communications Unified Session Manager does not validate any rn or cic information. Instead, it simply routes the request. Note that the Oracle Communications Unified Session Manager uses cic information instead of rn if both are present in the request. RFC 4694 compliant circumstances under which the Oracle Communications Unified Session Manager does not use rn, cic and npdi information include:

  • Invalid routing information, including rn present, but npdi missing.
  • Invalid routing information, including npdi present, but rn missing.
  • Request uses a sip-URI presented without user=phone.

If the request includes originating services as well as cic/rn/npdi information, the Oracle Communications Unified Session Manager performs those services rather than break out. If, after completing originating services, the request still includes cic/rn/npdi information, the system performs this breakout.