Open Settlement Protocol

The European Telecommunications Standards Institute (ETSI) Project TIPHON (Telecommunications and Internet Protocol Harmonization Over Networks) Open Settlement Protocol (OSP) provides a way for VoIP service providers to use services provided by OSP clearinghouses. This client/server protocol is used to exchange accounting, authorization, and usage information. The purpose of OSP is to manage access control, accounting, and interdomain routing. You can use this protocol between H.323 GWs, H.323 GKs, softswitches, and SIP proxies. Public Key Infrastructure (PKI) is used to provide secure services. The server creates a secure link for the transfer of information. When the link is established, a secure token-based signature is used to certify that the call is authorized. Clearinghouses provide best route and least cost path selections based on subscriber requirements.