Robert Schmidt
1948858c35
PDU Session Release
This MR implements end-to-end PDU Session Release functionality
according to 3GPP TS 38.413 and TS 38.331 specifications.
Reason for Change Previous implementation had incomplete and wrongly
places tunnel cleanup during PDU session release. UP cleanup shall be
done at CUUP, RRCReconfiguration shall be sent after retrieval of
updated CellGroupConfig from the DU. This implies F1 and E1 exchanges
during PDU session release procedure.
Major Changes:
1. RRC PDU Session Release: DRBs and PDU session teardown in NGAP PDU
Session Release Response callback
- Helper Functions: Introduced rm_pduSession,
find_drb_by_pdusession_id and rm_drbs() helpers to locate and clean
up DRBs linked to a specific PDU session
- Targeted Cleanup: RRC PDU Session and per-session DRB removal in
rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE()
- Status Cleanup: Removed unused PDU_SESSION_STATUS_RELEASED status
2. RRC PDU Session Release: Refactor
rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND
- Any PDU session in the pdusession_release_params list that is
present in the RRC list can be set to release, regardless of its
status
- Function Signature Update: Updated function signature and other
minor changes
- Response Handling: rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE is
sent upon completion of RRCReconfiguration
3. RRC PDU Session Release: add missing procedures E1AP Integration:
- Populates E1AP Bearer Modification for each to be released session
- PDCP Enhancement: Added nr_pdcp_release_drbs() to remove all DRBs
linked to a given PDU session in CUUP
- GTP-U Cleanup: GTP tunnel teardown handled in CUUP
e1_bearer_context_modif() using correct F1 or N3 GTP instance
4. NR PDCP/GTP:
- Enhanced Tunnel Deletion Logic: Separate handling for N3 tunnels (1
per PDU session) and F1-U tunnels (1 per DRB)
- New PDCP API Function: Added nr_pdcp_get_drb_ids_for_pdusession()
function to retrieve all DRB IDs associated with a specific PDU
session
5. RRC PDU Session Release: F1AP-based UE Context Modification:
- Replaced direct RRC message transfer with F1AP UE Context
Modification Request for proper retrieval from DU
- Cell Group Configuration: handling of updated CellGroupConfig from
DU ensures DRB release at CU
6. Docs and testing:
- Added PDU session add/remove test cases to 25 PRB RFSIM pipeline
- Documentation: Added PDU Session Release sequence diagram
- Telnet Commands: Added ci command to trigger NGAP PDU Session
Release and ciUE command to trigger establishment of a new PDU
Session
7. Additional fixes:
- UE RLC Management: ensure release of RLC entities
- Unify NG delay control before calling the RRC NGAP handler, for both
Setup and Release
8. Code Cleanup: Cleaned up unused GTP teardown functions.
Closes #867
|
OpenAirInterface documentation overview |
This is the general overview page of the OpenAirInterface documentation.
This page groups links to general information, tutorials, design documents, radio integration, and special-purpose libraries.
IMPORTANT NOTE:
Before reading this documentation, we strongly advise you to keep your own repository rebased on develop
or at least to checkout the documentation on the version of the repository you are using.
Then the documentation will better reflect the features available in your repository so that you may avoid some errors.
Beware if you previously pulled the develop branch that your repository may be now behind develop.
[[TOC]]
General
- FEATURE_SET.md: lists supported features
- GET_SOURCES.md: how to download the sources
- BUILD.md: how to build the sources
- code-style-contrib.md: overall working practices, code style, and review process
- cross-compile.md: how to cross-compile OAI for ARM
- clang-format.md: how to format the code
- sanitizers.md: how to run with ASan/UBSan/MemSAN/TSan
- environment-variables.md: the environment variables used by OAI
- tuning_and_security.md: performance and security considerations
There is some general information in the OpenAirInterface Gitlab Wiki
Tutorials
- Step-by-step tutorials to set up 5G:
- RUNMODEM.md: Generic information on how to
- Run simulators
- Run with hardware
- Specific OAI modes (phy-test, do-ra, noS1)
- (5G) Using SDAP and custom DRBs
- IF setups and arbitrary frequencies
- MIMO
- How to run OAI with O-RAN 7.2 FHI
- How to run a 5G-NSA setup
- How to run a 4G setup using L1 simulator Note: we recommend the RFsimulator
- How to use the L2 simulator
- How to use the OAI channel simulator
- How to use multiple BWPs
- How to run OAI-VNF and OAI-PNF: how to run the FAPI/nFAPI split, including some general remarks on FAPI/nFAPI.
- How to use the positioning reference signal (PRS)
- How to use device-to-device communication (D2D, 4G)
- How to run with E2 agent
- How to run the physical simulators
- How to setup OAI with Nvidia Aerial and Foxconn
- How to setup OAI with LDPC accelerators (Xilinx T2/Intel ACCs)
- How to setup OAI with the XDMA FPGA LDPC accelerator
- How to do a handover
- How to setup gNB frequency
- How to use the RT data recording app
Legacy unmaintained files:
L2NFAPI_NOS1.md,L2NFAPI_S1.md: old L2simulator, not valid anymore
Designs
- General software architecture notes: SW_archi.md
- Information on E1
- Information on F1
- Information on how NR nFAPI works
- Flow graph of the L1 in gNB
- L1 threads in NR-UE
- Information on gNB MAC
- Information on gNB RRC
- Information on analog beamforming implementation
- Information on the UE 5G NAS implementation
- Information on UL-MIMO: UL-MIMO specific notes
Building and running from images
- How to build images
- How to run 5G with the RFsimulator from images
- How to run 4G with the RFsimulator from images
- How to run physical simulators in OpenShift
Libraries
General
- The T tracer: a generic tracing tool (VCD, Wireshark, GUI, to save for later, ...)
- OPT: how to trace to wireshark
- The configuration module
- The logging module
- The shared object loader
- The threadpool used in L1
- The LDPC implementation is a shared library
- The time management module
Radios
Some directories under radio contain READMEs:
The other SDRs (AW2S, LimeSDR, ...) have no READMEs.
Special-purpose libraries
- OAI has two scopes: one based on Xforms and one based on imgui, described in this README
- OAI comes with an integrated telnet server to monitor and control
- OAI comes with an integrated web server
Testing
- UnitTests.md explains the unit testing setup
- Component tests are under
tests/. Currently, there is a simple CU-UP tester, see the corresponding README.md. - TESTBenches.md lists the CI setup and links to pipelines
- The CI setup uses a custom framework to run end-to-end tests.
Developer tools
- formatting is a clang-format error detection tool
- iwyu is a tool to detect
#includeerrors - docker-dev-env is a ubuntu24 docker development environment