PEPPOL 4-corner model
Peppol enables trading partners to exchange standards-based electronic documents over the Peppol network based on a 4-corner model:
The Peppol framework mandates the use of access points to ensure the delivery of consistent data between suppliers and customers. This provides an interoperable and secure network - connecting all participants using the same electronic messaging protocol and formats, while applying digital signature technologies to secure message content.
Service Metadata Publisher:
All Peppol participating organisations publish their receiving capabilities using a separate service called a Service Metadata Publisher (SMP) – the purpose is similar to an address book / business registry of participants.
Service Metadata Locator:
In order to deliver electronic documents from a sender to the correct recipient, all Peppol Access Points need to know about each other and the participants they support. To do this OpenPEPPOL maintains a centralised service, called the Service Metadata Locator (SML) which identifies all PEPPOL trusted Access Points and SMP’s.