Three Components of Network I/O Statistics on a LM Server (112020)

SUMMARY

The LAN Manager server displays various workstation and server statistics in the Net Admin screen. The workstation statistics include three categories of Network I/O: redirector, server and application. This article explains these categories.

You can obtain Net Admin screen statistics with the NetStatisticsGet2() API call explained in the "LAN Manager Programmer's Reference Manual," version 2.2, page 562.

In general:

Server I/O tracks commands or activities performed on a client and involving connecting to a server or getting the server to answer.
Redirector I/O tracks activities you perform on the server to use the workstation service (such as making "net use" to other servers) or that are initiated by the workstation service to maintain connections to remote servers.
Applications I/O tracks activities performed by other services and by NetBIOS applications.

MORE INFORMATION

Network I/O has three components: Redirector I/O, Server I/O and Application I/O.

Redirector I/O

The redirector issues NCBs to maintain connections between remote servers and the workstation service itself, to interact with the remote servers to establish connections, or to complete any activity initiated by the workstation service.

Workstation Service <---> Server Service
                       Workstation service <-->Server Service

Client                      Server                  Server

Server I/O

The server service does "housekeeping" to maintain client connections and to help clients connect to resources:

Server Service<-->(Redirector)<-->(Redirector)<-->Workstation Service

[S E R V E R]                                     [C L I E N T]

Application I/O

Application I/O is, essentially, what is left over after the above two categories are compiled: any other issuance by an application or service of NCBs to perform network functions. For example:

Messenger service issuing a Net Send command increments Application I/O by 5 or however many NCBs it issues to send a message.
Net View uses four NCBs, so it increments Application I/O by four.

Any application can issue an NCB by means of an NCB Submit command.