In all versions of 4D, the old/legacy network layer does not support sleep mode which means that whenever a client computer enter energy saving or sleep mode, 4D immediately treats this client machine as if the computer has crashed, and the user will remain on the server based on the server timeout settings or dropped in the server admin window. When the client machine awakens, a network error will occur and prompt the user to reconnect to the server.

However, the new network layer (starting in v17) fully supports sleeping clients with the "Sleeping" status in the server admin window and continues to keep the client connected. If the client happens to crash or move into a new location of a different IP address, the previous is removed in place of a new session. Likewise, the client can also be manually dropped via server admin window.