Traffic Director works similarly to the typical service mesh model, but it’s different in a few, very crucial ways. Traffic Director provides:

• A fully managed and highly available control plane. You don’t install it, it doesn’t run in your cluster, and you don’t need to maintain it. Google Cloud manages all this for you with production-level service-level objectives (SLOs).
• Global load balancing with capacity and health awareness and failovers.
• Integrated security features to enable a zero-trust security posture.
• Rich control plane and data plane observability features.
• Support for multi-environment service meshes spanning across multicluster Kubernetes, hybrid cloud, VMs, gRPC services, and more.

Traffic Director is the control plane and the services in the Kubernetes cluster, each with sidecar proxies, connect to Traffic Director. Traffic Director provides the information that the proxies need to route requests. For example, application code on a Pod that belongs to Service A sends a request. The sidecar proxy running alongside this Pod handles the request and routes it to a Pod that belongs to Service B.