To communicate with a resource, workspace, or artifact repository server in another zone, a "gateway" must be created.
A gateway object contains two resource (agent) machines. For example, GatewayResource1 and GatewayResource2 are each configured to communicate with the other. One gateway resource resides in the source zone and the other in the target zone.
A gateway is bidirectional and informs the CloudBees CD/RO server that each gateway machine is configured to communicate with its other gateway machine (in another zone).