About ZNS Clustering
A Zentera Network Switch Cluster is made up of multiple ZNS nodes, and is used to switch inter-domain (CoIP WAN) traffic between endpoints. ZNS clusters are typically deployed at each site, to ensure low latency remote access to Applications in the site.
zCenter load balances CoIP WAN sessions across the nodes in a cluster, and continually monitors their health. If a node in a ZNS cluster fails, it is removed from service, and its active connections are automatically re-provisioned to other healthy nodes in the cluster.
ZNS clustering provides two major benefits: redundancy to protect against hardware/software failure, and load balancing. Arbitrary aggregate bandwidth can be achieved by adding more ZNS nodes to a cluster.
Each zCenter node contains a small ZNS node (“default ZNS”) to provide connectivity even if an entire cluster is unreachable. This can also be used for smaller, non-critical deployments.
ZNS Cluster Selection
There are several levels of hierarchy used to select the ZNS for a CoIP WAN connection.
A ZNS cluster specified at the Application level is used
If an Application ZNS cluster assignment is not specified or not available, the cluster specified for the App Profile is used
If the App Profile ZNS cluster assignment is not specified or not available, the cluster specified at the service level is used (common to all tenants)
If the service level ZNS cluster assignment is not specified or not available, the zCenter default cluster is used