Wildcard Public User Identity (PUI)
The Oracle Communications Session Border Controller supports wildcard Public User Identies (PUI). This capability is most often used to streamline processing of REGISTER and INVITE messages between a PBX and an IMS core.
The HSS (Home Subscriber Server, an IMS network-wide database) is pre-provisioned with the extension numbers associated with the PBX’s base telephone number. When the PBX registers its own base telephone number with the S-CSCF, that server downloads a wildcarded PUI -- a regular expression that describes all extension numbers associated with the registering PBX
The S-CSCF returns the wildcarded PUI in the 200 OK response to the REGISTER message. Upon receiving the 200 OK, the SBC (acing in the P-CSCF role) uses the wildcarded PUI to construct a registration cache entry to implicitly treat subsequent INVITEs from PBXs extensions that match the wildcard as registered endpoints.
A wildcarded PUI consists of a delimited regular expression located either in the user info portion of the SIP URI or in the telephone-subscriber portion of the Tel URI. The regular expression takes the form of an Extended Regular Expressions (ERE) as defined in chapter 9 of The Single UNIX Specification (IEEE 1003.1-2004 Part 1). The exclamation mark (!) serves as the delimiter.
For example, the following PUIs will match to the wildcard ERE "sip:chatlist!.*!@example.com".
sip:chatlist1@example.com sip:chatlist2@example.com sip:chatlist42@example.com sip:chatlistAbC@example.com sip:chatlist!1@example.com
In addition to the ability of the P-CSCF to recognize and parse a wildcarded PUI, The P-CSCF must also support the PATH and P-Profile-Key SIP headers.
