The cascade deployment model architecture includes two instances of the VMware Tunnel with separate roles. In cascade mode, the front-end server resides in the DMZ and communicates to the back-end server in your internal network.
Only the Per-App Tunnel component supports the cascade deployment model. Cascade mode supports a relay-endpoint service if you use the Per-app component and the proxy component in combination. If you use only the proxy component, you must use the Relay-Endpoint model. For more information, see Relay-Endpoint Deployment Mode.
Devices access the front-end server for cascade mode using a configured hostname over configured ports. The default port for accessing the front-end server is port 8443. The back-end server for cascade mode is installed in the internal network hosting your intranet sites and web applications. This deployment model separates the publicly available front-end server from the back-end server that connects directly to internal resources, providing an extra layer of security.
The front-end server facilitates authentication of devices by connecting to AWCM when requests are made to the VMware Tunnel. When a device makes a request to the VMware Tunnel, the front-end server determines if the device is authorized to access the service. Once authenticated, the request is forwarded securely using TLS over a single port to the back-end server.
The back-end server connects to the internal DNS or IP requested by the device.
Cascade mode communicates using TLS connection (or optional DTLS connection). You can host as many front-end and back-end servers as you like. Each front-end server acts independently when searching for an active back-end server to connect devices to the internal network. Each back-end server must share the same hostname. You can set up multiple DNS entries in a DNS lookup table to allow load balancing.
Both the front-end and back-end servers communicate with the AirWatch API server and AWCM. The API server delivers the VMware Tunnel configuration and the AWCM delivers device authentication, whitelisting, and traffic rules. The front-end and back-end server communicates with API/AWCM through direct TLS connections unless you enable outbound proxy calls. Use this connection if the front-end server cannot reach the API/AWCM servers. If enabled, front-end servers connect through the back-end server to the API/AWCM servers. This traffic, and the back-end traffic, route using server-side traffic rules.