HTTP Client Operating Modes

The SBC supports STIR/SHAKEN deployments that follow either the 3rd Generation Partnership Project (3GPP) or the Alliance for Telecommunications Industry Solutions (ATIS) specification. The ATIS group is a North American standards development group that is one of several 3GPP Organizational Partners. The STIR/SHAKEN Client Operation section details both authentication and verification behavior when configured for STIR/SHAKEN. All of those behaviors apply when operating in ATIS mode. When operating in 3GPP mode, however the SBC uses some different behaviors, especially with regards to verification.

ATIS architecture supports verifying SHAKEN passports. 3GPP supports verifying DIV passports in addition to SHAKEN passports. The DIV category refers to passports generated for diverted calls. To prevent against intercepted calls, a SHAKEN passport includes both called and calling numbers, which can both be verified. But a diverted call includes a change to the calling number, which SHAKEN cannot support.

To alleviate this, the DIV passport can be used in addition to the SHAKEN passport. A DIV passport does not include an attestation level, with full attestation assumed. In addition to call diversion, the DIV standard also adds value to flows that need simultaneous ringing and emergency URN support. The SBC supports either architecture to provide you with flexibility within your deployments.

To define deployment type, the SBC provides the http-rest-type parameter under the sti-server element. You configure http-rest-type on a per-server basis to either ATIS (default) or 3GPP. This sets the operating mode of that server.