oracle链接问题

[hfcc999]

使用asp.net连接oracle数据库，打开数据库链接时出现异常，错误消息如下：
System.Data.OracleClient.OracleException: ORA-12535: TNS: 操作超时 at System.Data.OracleClient.DBObjectPool.GetObject(Object owningObject, Boolean& isInTransaction) at System.Data.OracleClient.OracleConnectionPoolManager.GetPooledConnection(String encryptedConnectionString, OracleConnectionString options, OracleConnection owningObject, Boolean& isInTransaction) at System.Data.OracleClient.OracleConnection.OpenInternal(OracleConnectionString parsedConnectionString, Object transact) at System.Data.OracleClient.OracleConnection.Open() .
有哪位高人知道解决办法。