Distinct and Wildcarded Public Service Identity (PSI) Support
The Oracle Communications Core Session Manager supports the use of distinct Public Service Identity (PSI) and wildcarded PSIs, typically for specifying access to a service. There is no configuration required on the Oracle Communications Core Session Manager to enable this support.
Administrators use individual PSI entries and/or wildcarded PSIs as service identifiers on an HSS. These identifiers provide the information needed to direct applicable messages to applicable application servers. Distinct PSIs can reside within individual PSI entries; wildcarded PSI entries are managed within iFC lists. Wildcarded PSI support is typically implemented to reduce HSS resource requirements. By configuring a wildcarded PSI, administrators can use a single record within the iFC to manage multiple resources.
A wildcard is composed of an expression that, when used in a user part, provides for access to multiple service resources. The regular expressions themselves are in form of Perl Compatible Extended Regular Expressions (PCRE).
For example, consider the following two service resources:
- sip:chatroom-12@core.com
- sip:chatroom-64@core.com
These two service resources can be represented simultaneously at the HSS using the following syntax:
- sip:chatroom-!.*!@core.com
The Oracle Communications Core Session Manager caches filter criteria information that uses this wildcard syntax. This avoids the need for SAR/SAA exchanges between the Oracle Communications Core Session Manager and the HSS every time an entity requests the service. The Oracle Communications Core Session Manager is equally capable of caching distinct PSIs, which similarly offloads the need for SAR/SAA exchanges during service resource location processes.
For most call flows, the Oracle Communications Core Session Manager does not evaluate the expression for the purpose of finding a match. Instead, it keeps the syntax provided by the HSS in its cache and provides the wildcarded syntax in the applicable AVP.
To allow the feature, the Oracle Communications Core Session Manager supports:
- Wildcarded public user identity AVP in the LIA, SAR and SAA
- User Profile AVP in the SAA
- P-Profile-Key across the Mw interface, as defined in RFC 5002