Federated Agent Metadata Synchronization Protocol (FAMS-P)

Abstract

This document specifies the Federated Agent Metadata Synchronization Protocol (FAMS-P), a normative protocol realization of the "BGP-like structured peering" federation mode (Mode B) defined in the two-layer DAWN discovery architecture (draft-zhang-dawn-agent-discovery-framework). FAMS-P is a peer-to-peer unicast protocol for synchronizing agent discovery metadata between Federation Gateways (FGWs) across administrative domains, in deployments where the preferred DNS delegation model does not meet operational requirements, such as closed trusted federations of approximately 2 to 200 sites. FAMS-P runs over mutually-authenticated TLS 1.3 sessions between peering gateways. It supports initial full metadata synchronization and incremental updates for agent online, offline, and change events. Each gateway maintains a local Federated Agent Directory (FAD). The protocol synchronizes only lightweight Federation Metadata Records (FMRs) — a concrete binding of the DAWN Minimum Discoverable Information (MDI) — and thus transfers only the minimum public discovery information permitted by the DAWN charter; richer capability retrieval is out of scope. The protocol defines complete message formats, a session state machine with connection collision resolution, timestamp-and-replay- protected conflict resolution, mandatory FMR origin signatures, time-to-live aging with bounded refresh jitter, and fine-grained per-peer export policy enforcement.