The document provides an overview of the Microservice Bus (MSB) which provides a communication infrastructure to support microservice architecture. Key components of MSB include service registration using a registry like Consul, client-side and server-side service discovery, and API gateways. MSB also includes tools like the Kube2MSB registrator to automatically register services deployed on Kubernetes. Examples are provided for running MSB without and within the ONAP Operations Manager (OOM). The future vision is presented of integrating service mesh technologies into the ONAP Microservice Architecture (OMSA) for carrier-grade microservices.