The requirements described in the previous clauses entail the following interfaces:
• between the DPI-FE and remote network entities (see clause 8.1), and
• between DPI-FE internal components (see clause 8.2).
Figure 8-1 depicts the external interfaces of the DPI-FE:
Figure 8-1 – External DPI-FE interfaces
8.1.1 Inspected traffic (p1)
The DPI-FE exchanges packets with remote packet nodes via p1. The packet path topology is point-to-point for a DPI-FE acting in the In-Path DPI mode. Multipoint topologies are not supported. Interface p1 covers bidirectional packet paths.
The packet path topology for a DPI-FE acting in the Out-of-Path DPI mode is related to an endpoint.
8.1.2 Control/management of traffic inspection (e1)
The DPI policy decision functional entity (DPI-PDFE) aims to control or manage the DPI-FE. The information exchanged via e1 thus concerns the commands for controlling/configuring the packet handling behaviour of the DPI-FE. Such commands could be described in a DPI policy.
Interface e1 could also support reporting and notification from DPI-FE to DPI-PDFE.
8.1.3 Reporting to other network entities (e2)
Interface e2 encompasses all possible communication interfaces with remote network entities other than the DPI-PDFE. This interface primarily supports reporting.
Figure 8-2 shows the possible internal interfaces based on the DPI requirements:
Figure 8-2 – Internal DPI-FE interfaces
There might be further DPI-FE internal functional components and internal interfaces. The internal interfaces are for further study.
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