Google Cloud offers a variety of support packages to accommodate your support needs. All Google Cloud Support packages include support for Anthos Service Mesh for customers who have purchased Anthos licenses. If you have an existing Anthos license, you already have support for Anthos Service Mesh.
For existing generally-available products, such as GKE and GKE on-prem, Google Cloud Support offers first line support as usual. For more information, see the following support pages:
Version Support Policy
The objective of this Version Support Policy is to provide you the flexibility to schedule upgrades when it meets your business needs, while balancing the rapid evolution of Istio, Kubernetes, GKE on-prem, GKE, and Anthos Service Mesh.
Google supports the latest Anthos Service Mesh released version and one version prior to the latest version. For example, when Anthos Service Mesh v1.6 is released, the supported versions will be Anthos Service Mesh v1.6 and Anthos Service Mesh v1.5.
For a list of the supported versions of GKE and GKE on-prem, see Supported environments.