# Software Revision MIB representation

The Software Revision MIB represents all NMS software packages installed in a system. Each file in each installed software revision is tracked in the MIB. The Software Revision agent keeps the MIB up-to-date as packages are installed or removed. However, the agent cannot track revisions of NMS files manually copied to or deleted from a system (that is, without use of NMS installation software).

To keep the MIB up to date, the Software Revision agent relies on information from the module identification signature files (.sgn files) installed with Natural Access. These files are stored in the \nms\bin directory (/opt/nms/bin under UNIX). When the Natural Access Server (ctdaemon) is restarted, the Software Revision agent modifies the MIB to match the current set of signature files.

Note: Certain NMS patches do not install their .sgn files in the \nms\bin or /opt/nms/bin directory. If the .sgn file is not installed in one of these directories, locate the file and manually copy it to the correct directory. The MIB cannot track a patch unless its .sgn file is in the correct directory.

Once you have installed NMS packages, service packs, or patches, the values in the Software Revision MIB are updated automatically when you restart the Natural Access Server (ctdaemon).

## Software Revision MIB structure

The Software Revision MIB represents a system as a single managed node that contains all packages installed within it. There are three major tables within the Software Revision MIB:

Table | Description
--- | ---
Package | Lists each package name and base version.
File | Lists each file in a package and the file version.
Patch | Lists patches or service packs applied to each package.

The following illustration shows the relationship between the tables in the Software Revision MIB:

As the illustration shows, each package is identified by a unique package index pkgIndex, which is assigned to it in the Package table. In the File table, files are listed by package index and each file is assigned a unique file index fileIndex. The file version of each file is also given here. In the illustration, agtrace.exe and ctdaemon.exe are part of the Natural Access 4.13 package (pkgIndex #1). Since the package was installed, Patch #2112 has modified agtrace.exe and Patch #3671 has modified ctdaemon.exe.

In the Patch Table, each installed service pack and patch is listed by the pkgIndex of the package it modified. Each patch is assigned a unique patch index patchIndex.

The following illustration shows the sequence of objects in the Software Revision MIB: