- Global ESB: All services share one namespace, and each service provider is visible to every service requester across a heterogeneous, centrally administered, geographically distributed environment. Used by departments or small enterprises where all the services are likely to be applicable throughout the organization.
- Directly connected ESB: A common service registry makes all of the services in several independent ESB installations visible. Used where services are provided and managed by a line of business but made available enterprise-wide.
- Brokered ESB: Bridge services that selectively expose requesters or providers to partners in other domains regulate sharing among multiple ESB installations that each manages its own namespace. Service interactions between ESBs are facilitated through a common broker that implements the bridge services. Used by departments that develop and manage their own services, but share a few of them, or selectively access services provided across the enterprise.
- Federated ESB: One master ESB to which several dependent ESBs are federated. Service consumers and providers connect to the master or to a dependent ESB to access services throughout the network. Used by organizations that want to federate a set of moderately autonomous departments under the umbrella of a supervising department.