With the rapid advancement of generative artificial intelligence (AI) and large language model (LLM) technologies, AI agents are gradually becoming the core service units in networks, and their communication mode is evolving from local collaboration to wide-area interconnection. The construction of the Internet of Agents (IoA) faces multiple challenges, such as identity management, dynamic networking, and semantic routing, which urgently requires the design of a network protocol system that adapts to its new traffic characteristics and collaboration needs. Based on the application scenarios of agent communication, this paper systematically analyzes the management, control, and routing requirements that multi-agent collaboration imposes on IP networks, proposes a three-layer functional architecture for the IoA, and designs a protocol suite covering management, control, and routing around key issues such as agent registration and identification, service discovery, capability sensing, and cross-domain traffic assurance. By extending existing Internet protocols and introducing a semantically aware routing mechanism, this paper provides a scalable, efficient, and secure approach to implementing a protocol for end-to-end agent collaboration, thereby contributing to the construction of an open, large-scale agent collaboration ecosystem.