A Layered Protocol Architecture for the Internet of Agents

Large Language Models (LLMs) can learn domain-specific languages such as APIs and tool interfaces, enabling agents that act through standardized protocols like MCP. But LLM context windows cannot grow indefinitely, so scaling beyond individual capacity requires agent collaboration -- the "Internet of Agents" (IoA). Current network stacks (OSI, TCP/IP) were designed for data delivery, not semantic coordination, so we propose two new layers: an Agent Communication Layer (L8)} that standardizes message envelopes, speech-act performatives, and interaction patterns; and an Agent Semantic Layer (L9) that negotiates a shared context, grounds and disambiguates content against it, and provides consensus primitives for population-scale coordination. On two real datasets and two LLMs, L9's schema-grounded disambiguation improves accuracy on ambiguous requests by 13--72 percentage points over blind guessing, at no added cost when disambiguation is not needed; an ablation shows this gain is schema-specific for open-domain QA but not for structured slot-filling, where the protocol's round-trip structure alone already suffices.