Overview

Currently, control loops are VNF oriented, more specifically on VNF orchestration use cases. Here, we are examining how the control loop concept and implementation might be expanded so that it could be used to support PNF use cases.

Problem Statement

There are many PNF use cases that are inherently Control Loop "friendly" and can be described in terms of a Monitor→Analyse→Plan→Act autonomic (MAPE) control loop. Such loops are supported today in ONAP control loop for certain VNF orchestration use cases.

Some Proof of concepts have been implemented using PNFs in ONAP, but to date this has been achieved by "pretending" that the PNF is a VNF and adapting one of the existing Control Loop implementations such as the vCPE one to execute the logic of the PNF use case.

The problem statement is "to explicitly support PNFs, PNFs and PNF/VNF use cases in ONAP".

Business Requirement

There are a number of categories of  PNF related use cases that could be addressed by ONAP control loop support:

• Routine Management of PNF nodes, functions such as health checks and data collection
• Management of non real time aspects of the physical network itself
• Management of Network Slices (Could have PNF and VNF aspects)
• Management for specific domain problems
• Network monitoring condition update can be progressed on specific resource/NF instances instead of resource/NF specification

• Investigate further the boundaries between control loop/blueprint definition at design time and CLAMP capability to configure DCAE application in a control loop (control loop initiation tool)

• Allow update of control loops at runtime

  • add a selected node instance to a control loop

  • Create a new control loop extending an existing control loop behavior

Participating Companies

Ericsson, ......

Goals

To bring in direct support for PNFs into ONAP control loops.

• Definition and execution of PNF control loops
• Triggering of control loops at PNF instantiation
• Support for PNFs in control loop components and events
• Support in DCAE for PNF focussed microservices
• Storage of data for PNF domains (in microservice? in A&AI?)
• Allow update of control loops at runtime

Contributions

Impacts

The following projects could be impacted.

SDC

A&AI

Modelling

Policy

CLAMP

Controllers

DCAE

Open Questions

• DCAE ms blueprint relation with resource/service specification vs an agnostic DCAE ms...
• Explore and clarify, current limitation about use of CLAMP in case of other DCAE analytic applications instead of TCA

• Can I update an existing DCAE ms blueprint when a new Control loop is created ?

• Can I have multiple Control Loops using the same DCAE ms ?

Further questions:

• How is μs initial default configuration handled? Is it specified in SDC blueprint, then populated into Consul at μs instantiation time?
• How is μs default configuration changed? Do you update the service via SDC/Blueprint or do you update it in Consul at run time?
• How can we make node/VNF/PNF specific changes to μs config at run time? Store in A&AI entry for PNF/VNF?
• How can we make temporary changes to groups of PNF/VNF config at run time for troubleshooting in zones etc? Using configuration policies with CLAMP that push changes to Consul?
• What's the official view on GUIs/Clients on an individual μs for doing configuration of a μs?