# Package net.corda.node.services.network

- Interface Summary
  Interface | Description
  --- | ---
  NetworkMapService | A network map contains lists of nodes on the network along with information about their identity keys, services they provide and host names or IP addresses where they can be connected to. This information is cached locally within nodes, by the `interface NetworkMapCache`. Currently very basic consensus controls are applied, using signed changes which replace each other based on a serial number present in the change.

- Class Summary
  Class | Description
  --- | ---
  AbstractNetworkMapService | Abstracted out core functionality as the basis for a persistent implementation, as well as existing in-memory implementation.
  InMemoryNetworkMapCache | Extremely simple in-memory cache of the network map.
  InMemoryNetworkMapService |
  LastAcknowledgeInfo |
  NodeRegistration | A node registration state in the network map.
  NodeRegistrationInfo |
  PersistentNetworkMapService | A network map service backed by a database to survive restarts of the node hosting it.
  WireNodeRegistration | A node registration and its signature as a pair.

- Exception Summary
  Exception | Description
  --- | ---
  NodeMapError |