lifecycle management.
This clause provides the flows of these operations for the VNF FG lifecycle management: • Create VNF Forwarding Graph;
• Update VNF Forwarding Graph; • Query VNF Forwarding Graph; and • Delete VNF Forwarding Graph.
The Network Service instance needs to be updated when any members (e.g. VNF or VL) composing this Network Service is changed. Therefore, the instantiation of a new VNF and modification of the information on VLR are needed for updating the Network Service. Each VNF FG is formed by multiple Connection Points and possibly a Network Forwarding Path (NFP) which indicates a traffic flow of the Network Service. The VNF FG needs to be updated when any VNF FG members (e.g. Connection Points or NFP) is changed. Therefore, the modification of VNF FG Record and update of NFP are needed for updating the VNF FG.
C.7.1 Create VNF Forwarding Graph
This flow refers to the process of creating a new VNF Forwarding Graph for an existing Network Service. Note that the corresponding Network Service has been instantiated already with the needed VNFs and VLs.
Figure C.14: VNFFG creation message flow The main steps for creating a VNF Forwarding Graph are:
1. The NFVO receives a request to create a new VNF Forwarding Graph for an existing Network Service using the operation Create VNFFG of the Network Service Lifecycle Management interface.
2. The NFVO validates the request including validation that the sender is authorized to issue this request and validation of the parameters passed for technical correctness and policy conformance.
3. The NFVO requests the allocation of the necessary network resources to set up the VNF Forwarding Graph using the operation Allocation Resource of the Virtualised Resources Management interface.
4. The VIM assigns the needed network resources for the VNF Forwarding Graph. 5. The VIM returns result of resource allocation back to the NFVO.
C.7.2 Update VNF Forwarding Graph
This flow refers to the process of updating an existing VNF Forwarding Graph for a Network Service. For this, the information of VNF Forwarding Graph Record and NFP associated to the VNF Forwarding Graph are updated. Note that this update process assumes that a new VNF or new VNFs might already be instantiated to be incorporated into an existing VNF Forwarding Graph.
Figure C.15: VNFFG update message flow The main steps for updating a VNF Forwarding Graph are:
1. The NFVO receives a request to update a VNF Forwarding Graph for an existing Network Service using the operation Update VNFFG of the Network Service lifecycle management interface.
2. The NFVO validates the request including validation that the sender is authorized to issue this request and validation of the parameters passed for technical correctness and policy conformance.
3. The NFVO requests to allocate necessary resources and network connectivity to update the VNF Forwarding Graph using the operation Allocation Resource of the Virtualised Resources Management interface.
4. The VIM assigns the needed network resources for the VNF Forwarding Graph. 5. The VIM returns result of resource allocation back to the NFVO.
6. The NFVO requests to the VIM to update NFP using the operation Update Network Forwarding Path of the Network Forwarding Path rule management interface.
7. The VIM processes the NFP update and performs the required configuration. 8. The VIM acknowledges the NFVO the NFP update.
9. The NFVO updates the VNF Forwarding Graph Record to reflect the information of new VNFs. 10. The NFVO returns result of VNF Forwarding Graph update back to the Sender.
C.7.3 Query VNF Forwarding Graph
This flow refers to the process of retrieving the information of an existing VNF Forwarding Graph for a Network Service.
Figure C.16: VNFFG query message flow The main steps for querying a VNF Forwarding Graph are:
1. The NFVO receives a request to query a VNF Forwarding Graph for an existing Network Service using the operation Query VNFFG of the Network Service Lifecycle Management interface.
2. The NFVO validates the request including validation that the sender is authorized to issue this request and validation of the parameters passed for technical correctness and policy conformance.
3. The NFVO returns the detailed information of VNF Forwarding Graph from the Network Service/ VNF Forwarding Graph repository to the Sender.
C.7.4 Delete VNF Forwarding Graph
This flow refers to the process of deleting an existing VNF Forwarding Graph which belongs to an existing Network Service.
The main steps for deleting a VNF Forwarding Graph are:
1. The NFVO receives a request to delete a VNF Forwarding Graph for an existing Network Service using the operation Delete VNFFG of the Network Service Lifecycle Management interface.
2. The NFVO validates the request including validation that the sender is authorized to issue this request and validation of the parameters passed for technical correctness and policy conformance.
3. The NFVO requests the release of the network resources assigned to this VNF Forwarding Graph using the operation Release Resource of the Virtualised Resources Management interface.
4. The VIM de-allocates the network resources used by the VNF Forwarding Graph. 5. The VIM returns result of resource de- allocation back to the NFVO.
Annex D (informative):
Orchestration flows
D.1 Introduction
This annex represents a collection (non-exhaustive) of Orchestration flows that should be possible to implement by means of the interfaces described in the main part of the present document.