Page 1432 - 5G Basics - Core Network Aspects

3 Signalling aspects

– Supporting the installation function for applications in the interface. The control layer enables the
application to program the data plane. The App layer determines the technology to be used and sets
the parameters for it;
– The Sn interface should distribute the up-called events to the appropriate App functions based on
the registered features of the App functions;
– Providing the management functions for the App functions to configure and manage the installed
modules in the controller.

The control layer provides a mechanism for new services/applications creation and existing
services/applications removal via the Sn interface. A specified transmission control protocol (TCP) port
number is provided for application registration, removal and coordination. When a new application is needed
in the unified IPv6 system, this new application will initiate a registration request to the control layer using
the specified TCP port number. Then the application and the control layer will coordinate an App ID and a
dedicated channel for this App. Then the new App will register its features (e.g., the appropriate packet
type(s) handled by the App) and/or install some function(s) to the control layer via the dedicated channel of
the App. Removal function is also achieved via the specified TCP port number.
8.2.1 Flow description

In this Recommendation, two parts of the flow table for IPv6 transition technology will be defined: Match
fields and Actions.

Match Fields Actions

The procedure to create the flow table is separated into two steps:

1. The Match field is defined as below:

Field Offset
Field length
2. The possible Actions of the Protocol-Unaware flow table are defined as: Action Type, e.g., set-field,
add-field and del-field.
Taking the set-field and add-field as examples:

Action Type Set-field
Set-field offset
Set-field length

Action Type Add-field
Add-field offset
Add-field length

8.2.2 IPv6 transition parameters in the flow table

The Sn interface enables the IPv6/IPv6 transition technology applications to manipulate traffic. The
parameters appearing in the flow table may be transmitted at this interface, which contains the following
information:
– tunnel_sip_v6: The source ipv6 address of tunnel (if any);
– tunnel_dip_v6: The destination ipv6 address of tunnel (if any);

– tunnel_sip_v4: The source ipv4 address of tunnel (if any);
– tunnel_dip_v4: The destination ipv4 address of tunnel (if any);

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