What is a Service Metadata Publisher (SMP) in the Peppol network?
A Service Metadata Publisher (SMP) is a directory server in the Peppol network that stores routing information for Peppol participants. When a sender wants to deliver a document to a Peppol participant, they query the SML (Service Metadata Locator) to find which SMP holds the recipient's routing information, then query the SMP to get the recipient's access point address and supported document types. This discovery mechanism allows any Peppol participant to find any other without pre-configured connections.
How do SMP and SML work together in the Peppol network?
Peppol discovery architecture: (1) SML (Service Metadata Locator) is a central DNS-based directory that maps participant IDs to their SMP address; (2) SMPs are distributed servers operated by access point providers containing the actual routing information (document types, endpoint URLs) for their registered participants; (3) When sending a document, the sender queries the SML first to find the SMP, then queries the SMP for routing details; (4) The sender's access point connects directly to the receiver's access point using the endpoint URL from the SMP.
Frequently Asked Questions
- Can a business manage its own SMP registration directly?
- Most businesses manage their SMP registration through their access point provider, who registers the business's participant ID in the SMP and maintains the routing entries. Technical SMP administration requires knowledge of the OASIS BDX specifications. Some large organizations and ERP vendors operate their own SMP for their own participant IDs. OpenPeppol provides the SMP specifications and the SML central infrastructure that all SMPs register with.
- What happens if a participant's SMP entry is incorrect?
- An incorrect SMP entry (wrong endpoint URL, missing document type, expired certificate) results in document delivery failure. The sending access point discovers the incorrect routing information and cannot deliver the invoice. Diagnostic tools can query the Peppol directory to check SMP entries. When an issue is identified, the participant's access point provider corrects the SMP entry; corrections typically propagate within minutes to hours. Senders should implement retry logic to handle transient SMP issues.