16.6.1 Oracle Net Error Stacks

Log files provide information contained in an error stack. An error stack refers to the information that is produced by each layer in an Oracle communications stack as the result of a network error.

Table 16-9 Error Stack Components

Error Stack Component	Description
NI	Network Interface. This layer provides a generic interface for Oracle clients, servers, or external processes to access Oracle Net functions. The NI layer handles the "break" and "reset" requests for a connection.
NS	Network Session (main and secondary layers). These layers receive requests from NI, and settle all generic computer-level connectivity issues, such as: The location of the server or destination (open, close functions). Whether one or more protocols are involved in the connection (open, close functions). How to handle interrupts between client and server based on the capabilities of each (send, receive functions).
NA	Network Authentication. This layer negotiates authentication and encryption requirements.
NT	Network Transport (main, secondary, and operating system layers). These layers map Oracle Net foundation layer functionality to industry-standard protocols.