Create external content type connect to sql server:timeout expired. the timeout period elapsed prior to completion of the operation ro the server is not responding

Hi Team,

i'm trying to create a external content type, that connect to my database in another server, i configure to Add Connection->Sql Server type, typein the sql server name and database name, after that the error just occurs that:

Cannot connect to the LobSystem (External System).

Timeout expired. the timeout period elapsed prior to completion of the operation or the server is not responding.