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10 E2E Network Slicing Use Case
11 ============================
15 The objective of this use case is to realize End-to-End 5G Network
16 Slicing using ONAP. An End-to-End Network Slice consists of RAN (Radio
17 Access Network), Transport Network (TN) and Core Network (CN) slice
18 sub-nets. This use case intends to demonstrate the modeling,
19 orchestration (life cycle and resources) and assurance of a network
20 slice which are implemented in alignment with relevant standards. The
21 key highlights of this use case include:
23 - Modular architecture providing building blocks and flexibility under
24 various deployment scenarios
26 - Functionality aligned with 3GPP and other relevant standards such as
29 - Interfaces and APIs aligned with relevant standards (3GPP, IETF,
30 ETSI, TM Forum, etc.) while enabling easy customization through use
31 of appropriate plug-ins. This would enable easier interoperability of
32 slice management functions realized within ONAP with 3\ :sup:`rd`
33 party slice management functions, as well as northbound and
36 - Taking a step-by-step approach to realizing different architectural
37 options in an extendable manner.
39 - Providing flexibility in network slice selection by providing an
40 option of manual intervention, as well as abstracting the network
43 - The use case implementation team is composed of service providers,
44 software and hardware vendors, solution providers and system
45 integrators thereby taking into consideration different perspectives
48 This use case is a multi-release effort in ONAP with the first steps
49 taken in Frankfurt release. It will continue to expand in scope both in
50 breadth and depth, and along the journey it shall also align with
51 updates to the relevant standards which are also currently evolving.
52 This use case shall also collaborate with other open initiatives such as
53 O-RAN to enable wider adoption and use.
55 Further details can be obtained from:
56 https://wiki.onap.org/display/DW/Use+Case+Description+and+Blueprint
62 +---------------+--------------------------------------------+
63 | Abbreviation | Meaning |
64 +===============+============================================+
65 | CSMF | Communication Service Management Function |
66 +---------------+--------------------------------------------+
67 | CSI | Communication Service Instance |
68 +---------------+--------------------------------------------+
69 | CST | Communication Service Template |
70 +---------------+--------------------------------------------+
71 | NSI | Network Slice Instance |
72 +---------------+--------------------------------------------+
73 | NSMF | Network Slice Management Function |
74 +---------------+--------------------------------------------+
75 | NSSI | Network Slice Sub-net Instance |
76 +---------------+--------------------------------------------+
77 | NSSMF | Network Slice Sub-net Management Function |
78 +---------------+--------------------------------------------+
79 | NST | Network Slice Template |
80 +---------------+--------------------------------------------+
81 | NSST | Network Slice Sub-net Template |
82 +---------------+--------------------------------------------+
85 Recap of Frankfurt functionality
86 --------------------------------
87 In Frankfurt release, CSMF and NSMF within ONAP was implemented, while connecting to an external Core NSSMF.
88 From the NSI Life Cycle perspective, the scope for Frankfurt included NSI design and pre-provision, NSI instantiation
89 and configuration, and NSI activation and deactivation. In particular:
91 - CSMF: Functions of slice service creation, slice service activation and deactivation were implemented.
93 - NSMF: Functions of NSI instantiation, NSI activation and deactivation were implemented. In addition, manual
94 intervention is also provided in NSMF slice task management portal to ensure the selected NSI/NSSI as well as
95 Service Profile and Slice Profile are OK or need adjustment.
97 - Design of CST, NST and onboarding NSST that are required to support the run-time orchestration functions
99 - To connect to the external (core) NSSMF, an adaptor was implemented to provide interface between ONAP and 3rd party
102 To support the above functions, code impacts in U-UI, SO, OOF and ExtAPI components, and schema change in A&AI
103 were implemented. For further details, see https://wiki.onap.org/display/DW/Proposed+Functions+for+R6+and+Impacted+Modules
105 As part of Frankfurt release work, we supported the minimum-scope installation of ONAP to reduce the resource requirements.
106 From the module perspective, 5G E2E Slicing use case involves SDC, SO, A&AI, UUI, EXT-API, OOF and Policy modules of ONAP.
107 So we will configure these required modules along with the mandatory common modules such as DMaaP. Further, for each module,
108 the use case also does not use all of the charts,so we removed the not needed Charts under those modules to optimize the
109 resources required for setting up the use case. This approach will help to install a minimum-scope version ONAP for the
110 E2E Slicing use case.
112 Further details of the installation steps are available at:
113 https://wiki.onap.org/display/DW/Install+Minimum+Scope+ONAP+for+5G+Network+Slicing
115 Scope of Guilin release
116 -----------------------
117 From the architecture point of view, in Guilin release, besides the continuation of NSMF which was implemented in
118 Frankfurt release, the RAN NSSMF, TN NSSMF, CORE NSSMF have been implemented within ONAP, apart from interacting with
119 ezternal RAN NSSMF and external CORE NSSMF.
121 The following provides an overview of the enhancements done in Guilin release:
123 - **Enhancements in NSMF**: Service Profile decomposition into Slice Profiles for 3 domains, NSI selection enhancement,
124 E2E slice instance creation including RAN, TN and CN slice sub-net instance creation/reuse, activation/deactivation
125 of E2E slice, and deciding whether to terminate E2E slice or not.
127 - **RAN NSSMF, TN NSSMF, CN NSSMF within ONAP**: Basic logic for all 3 NSSMFs to support NSSI allocation, activation,
128 deactivation, deletion and modification (in case of reuse of NSSI).
130 - **Enable NSMF interaction with RAN NSSMF, TN NSSMF, CN NSSMF**: Implement generic NSSMF adaptor for three domain NSSMFs,
131 alignment with standard intefaces (3GPP, IETF), enable the connection to external RAN NSSMF.
133 - **Design of RAN NSST, TN NSST, CN NSST and Slice Profiles, TN information models**: Basic E2E Slicing model was provided
134 all the related templates designed from SDC, TN related information models.
136 - **TMF 641 support**: Extension of the TMF 641 based interface from NB of ExtAPI to support service activation,
137 deactivation and termination.
139 - **RAN and CN NFs set up and initial configurations**: CN NF simulators was developed: AMF, SMF, UPF and configure the
140 S-NSSAI on CN NFs; RAN NF Simulator was enhanced for PM data reporting, CU and Near-RT RIC configuration.
142 - **KPI monitoring**: Implementation to request details of a KPI via UUI to ONAP DCAE. Providing the requested data to UUI
143 by DCAE using a new microservice (Data Exposure Service - DES). Enhancements in PM-Mapper to do KPI computation is
144 in progress, and will be completed in Honolulu release.
146 - **Closed Loop**: First steps to realizing a simple Closed Loop in the RAN using PM data collected from the RAN was
147 implemented - update the allowed throughput for a S-NSSAI per Near-RT RIC coverage area based on DL/UL PRB for data
148 traffic that was reported from the RAN. The analysis of the PM data was done using a new Slice Analysis MS in DCAE,
149 and the Policy-based Control Loop framework was applied to trigger the updates in the RAN.
151 - **Intelligent Slicing**: First steps to realizing a simple ML-based Closed Loop action in the RAN using PM data collected
152 from the RAN was implemented - update the maxNumberofConns for a S-NSSAI in each cell based on PDU session related
153 PM data that was reported from the RAN (PDU sessions requested, successfully setup and failed to be set up). The
154 training was done offline, and the ML model is onboarded as a micro-service to ONAP for demo purpose alone (it is
155 not part of ONAP code/repos). The ML model provides updates to the Slice Analysis MS, which then uses the
156 Policy-based Control Loop framework to trigger the updates in the RAN.
158 - **Modeling enhancements**: Necessary modeling enhancements to support all the above functionalities.
160 The base use case page for Guilin release is https://wiki.onap.org/display/DW/E2E+Network+Slicing+Use+Case+in+R7+Guilin.
164 (a) 2 deployment scenarios for RAN NSSI are supported. In the first scenario, the RAN NSSI comprises also of
165 TN Fronthaul (FH) and TN Midhaul (FH) NSSIs, and RAN NSSMF shall trigger TN NSSMF for TN FH and MH NSSI
166 related actions. In the second scenario, the RAN NSSI comprises only of RAN NFs. TN NSSMF shall be triggered by
167 NSMF for TN FH and MH NSSI related actions. This part is not yet implemented in NSMF, and will be realized in
170 (b) The Guilin release scope focused on enhancing NSMF and implementing basic functionality of all 3 NSSMFs within
171 ONAP with the objective of realizing a simple E2E network slice using standard interfaces. So, further enhancements
172 and refinement will continue in Honolulu release and beyond.
174 (c) Details of the assumptions in Guilin release are documented at:
175 https://wiki.onap.org/display/DW/Assumptions+for+Guilin+release
177 (d) Sequence/flow diagrams related to this use case are available at:
178 https://wiki.onap.org/display/DW/Use+case+flows
180 (e) Details of the Modeling aspects are available at:
181 https://wiki.onap.org/display/DW/Modeling+enhancements?src=contextnavpagetreemode
184 Impacted Modules for Guilin
185 ---------------------------
186 The code-impacted modules of E2E Network Slicing in Guilin release are:
188 - **SO**: Enhancements in NSMF explained above, NSSMF adaptor, workflows for RAN, Core and TN NSSMFs, Closed Loop
191 - **OOF**: Enhancements for NSI selection, NSSI selection, Slice Profile generation, and NSI/NSSI termination
194 - **DCAE**: 2 new MS were introduced:
195 (a) **Data Exposure Service (DES)** for querying database/datalake for PM/KPI data by any entity
196 (b) **Slice Analysis MS** for analyzing slice related PM/KPI data and determining necessary closed loop actions
198 - **AAI**: Updates for Slice Profile, NSST, Service Profile, TN slice models
200 - **SDN-C**: TN NSSMF related functionality (allocation, activation/deactivation and termination of TN NSSI/S-NSSAI)
202 - **CCSDK/SDN-R**: RAN NSSMF related functionality related to allocation, activation/deactivation and termination of RAN
203 NSSI/S-NSSAI, mainly the configuration of CUs, DUs and Near-RT RICs over O1 interface to the RAN NFs. In addition,
204 configuration updates related to Closed Loop and Intelligent Slicing shall also be sent over O1 interface.
206 - **U-UI**: Enhancements related to configuration/selection of end-points.
208 - **ExtAPI**: Enhancements to support service activation/deactivation and termination using TMF 641 APIs
210 - **Policy**: Minor updates to support the new Control Loop for Network Slicing.
212 Apart from the above, the following modules had test-only impact:
214 - **SDC**: Test of the supported functionality through creation of NST, NSST for all 3 domains, templates for Service
215 Profile and Slice Profile.
217 - **CDS**: Support for configuration of S-NSSAI in the Core NFs.
221 - **Config DB** is enhanced to support storing and retrieval of RAN-related configuration data. This is not an official
222 ONAP component, and its functionality is expected to be performed by the Configuration Persistence Service in
225 - **Core NF simulators** have been developed for instantiating as part of Core NSSI creation/configuration, and also
228 - **RAN-Sim** has been enhanced to include CU and Near-RT RIC functionality, apart from enhancements to DU functionality.
230 Details of the impacts/APIs of some of the modules listed above are available in the child pages of:
231 https://wiki.onap.org/display/DW/Impacted+Modules--Design+Details
234 Functional Test Cases
235 ---------------------
236 The functional testing of this use case shall cover creation and activation of a service with an E2E Network Slice
237 Instance which contains RAN, Transport and Core Slice Sub-net instances. It also addresses the termination of an
238 E2E Network Slice Instance. We classify the test cases into 7 tracks: CSMF, NSMF, Common NSMMF/RAN NSSMF/TN NSSMF/
239 Core NSSMF/KPI Monitoring/Close loop/Intelligent Slicing. Details of the test cases can be found at:
240 https://wiki.onap.org/display/DW/Track-wise+test+cases
245 The Guilin release setup details for the E2E Network Slicing use case will be available at the following page and its
247 https://wiki.onap.org/display/DW/Demo+setup+steps+for+Guilin
250 Known Issues and Resolutions
251 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
252 (a) A limited testing of the supported scenarios is being carried out in Guilin. For example, for NSI allocation, only
253 a sub-set of combinations of NSI reuse, creation using existing or new NSSIs (RAN, Core, TN) is being tested. However,
254 since the remaining functionality will be activated only when triggered with the appropriate inputs, this limitation
255 shall not affect the stability of the components or other existing functionality.
257 (b) The configuration updates for Closed Loop and Intelligent Slicing to the RAN is sent over O1 interface to Near-RT RIC.
258 It should be sent over A1 interface - this will be taken up in Honolulu release.
260 (c) Coverage area to TA list is not performed. Based on the coverage area provided as input, a set of cells are assumed to
263 (d) NST selection requires a file to be stored corresponding to the templates created in SDC. In Honolulu release, OOF
264 functionality will be enhanced to fetch the NSTs from SDC.
266 (e) RAN/Core NSSI endpoint determination, configuration and use is limited in Guilin release.
268 (f) Only creation of new TN NSSI is supported, reuse of existing TN NSSI is not yet supported.
270 (g) KPI computation functionality enhancements in PM-Mapper in DCAE is not part of Guilin release, though the functionality
271 is implemented and available.