Page 1010 - 5G Basics - Core Network Aspects

2 Transport aspects

End download: Signal the completion of a download image sequence, providing both CRC and version
information for final verification. This action is valid only for a software image instance that is currently
being downloaded (image 1 in state S2, image 0 in state S2' as shown in Figure S.3).
Activate image: Load/execute a software image. When this action is applied to a software image that is
currently inactive, execution of the current code image is suspended, the associated software image is
loaded from non-volatile memory, and execution of this new code image is initiated (that is, the associated
entity reboots on the previously inactive image). When this action is applied to a software image that is
already active, a soft restart is performed. The software image is not reloaded from non-volatile memory;
the current volatile code image is simply restarted. Set the is active attribute value to 1 for the target
software image instance and set the is active attribute value to 0 for the other software image. This action
is only valid for a valid software image.
Commit image: Set the is committed attribute value to 1 for the target software image instance and set the
is committed attribute value to 0 for the other software image. This causes the committed software image
to be loaded and executed by the boot code upon subsequent start-ups. This action is only applicable when
the target software image is valid.
NOTE – Software upgrade process using the above actions is exemplified in clause S.6.

S.4.2 Vendor-specific usage

In this application, the software image management is flexible, in keeping with the needs of particular
vendors and applications. The distinction between fundamental and vendor-specific usage is that the
managed software image instance shall not be a value that could be used in the fundamental usage
application. That is, this byte shall be neither 0016 nor 0116.

The NT automatically instantiates as many software image instances as it is prepared to support.
• In its vendor-specific usage, the support of attributes of the software image instances are optional.
• The actions are optional.

• Files might or might not exist in versioned pairs (previous revision, next revision).
S.4.2.1 File attributes for the vendor-specific usage

Each software image instance has the following manageable attributes:
Managed software image: This attribute distinguishes between software image instances, and in vendor-
specific usage is required to have neither the value 0016 nor the value 0116. It is suggested that the software
image be numbered consecutively beginning from 2 (mandatory) (1 byte).

Version: If this attribute is supported, its meaning is the same as that of the fundamental usage application
(optional) (14 bytes).

Is committed: This attribute indicates whether the associated file is committed (1) or uncommitted (0).
Vendor-specific instances might or might not exist in pairs, and might or might not support the concept of a
commit (optional) (1 byte).

Is active: This attribute indicates whether the associated file is active (1) or inactive (0). Vendor-specific
instances might or might not support the concept of an active state (optional) (1 byte).

Is valid: This attribute indicates whether the associated file is valid (1) or invalid (0). Vendor-specific
instances might or might not include a way to determine their validity (optional) (1 byte).

Product code: This attribute provides a way for a vendor to indicate product code information on a file. It is
a character string, padded with trailing nulls if it is shorter than 25 bytes (optional) (25 bytes).
Image hash: This attribute is an MD5 hash of the software image. It is computed at completion of the end
download action (optional) (16 bytes).

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