Cisco Cisco Cisco Cisco Agentic AI systems require messaging infrastructure that supports real-time collaboration, high-volume streaming, and dynamic group coordination across distributed networks. Traditional protocols like AMQP [AMQP], MQTT [MQTT], and NATS [NATS] address some requirements but fall short on security, particularly regarding post-compromise protection and forward secrecy essential for autonomous agents handling sensitive data. This document analyzes six messaging protocols—AMQP, MQTT, NATS, AMQP over WebSockets, Kafka, and AGNTCY SLIM—across dimensions critical for GenAI agent systems: streaming performance, delivery guarantees, security models, and operational complexity. We examine how each protocol's design decisions impact agentic AI deployments, from lightweight edge computing scenarios to large-scale multi- organizational collaborations. This document also describes Agent Mesh [AgentMesh], an overlay for agent service discovery, policy enforcement, and cross-network connectivity. It operates at the service-network layer, alongside messaging systems that provide message delivery and session semantics.