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
- Enable telnet server on VNF (gNB) and UE in docker-compose.yaml
- Add new test cases for PDU session management:
* Add PDU session via UE telnet
* Release PDU session via telnet
* Verify connectivity after PDU session release
- Integrate telnet commands into existing container_5g_rfsim_u0_25prb.xml pipeline
- Test cases added before undeploy step in proper execution order
1. Rename oai-flexric to nearRT-RIC. FlexRIC is a project combining nearRT-RIC, xApps, and E2 agent emulators.
2. Instead of undeploying all the containers at the same time, and not checking the logs for xApps and nearRT-RIC, do the following:
- Stop containers (docker compose stop) - one or subgroup of running containers in the following order:
a) xapp-kpm-moni
b) xapp-kpm-rc
c) xapp-gtp-mac-rlc-pdcp-moni
d) oai-nr-ue oai-nr-ue2
e) oai-gnb
f) nearRT-RIC
- Undeploy containers (docker compose down), collect and analyze all the logs.
- Add XML pipeline for N2 handover testing
- Add Docker compose for two monolithic gNBs
- Features:
* Two monolithic gNBs (gNB1, gNB2) with proper CU+DU parameters
* Gradual attenuation control using RC4DAT attenuator (5s duration)
* N2 handover sequence: gNB1 → gNB2 → gNB1
* Proper channel mapping: ch1-2 for gNB1, ch3-4 for gNB2
* Telnet server configuration for CI commands
* Handover-specific neighbor configuration
* Clean test state management with attenuator reset
Update based on !3645
Note: For some test configurations we still need to provide
ra_ResponseWindow, for more details, check commit message of
41d14b571c
CI: Upgrade Aerial setup to 25-2.1
The purpose of this MR is to upgrade the cuBB image in the Aerial setup to
release 25-2.1 and update the doc/Aerial_FAPI_Split_Tutorial.md accordingly.
Update cuBB image to cubb-build:25-2.1_srs-ul-heavy (release 25-2.1 with
changes in the L1 config to test heavy ul)
Co-authored-by: Reem Bahsoun <reem.bahsoun@openairinterface.org>
N2 handover
This MR introduces full support for N2 handover, covering handover
decision, preparation, execution, and notification between source and
target NG-RAN nodes.
Key features:
1. Handover Decision & Preparation:
- Implement N2 handover decision based on UE measurement reports.
- Generate the Handover Preparation Information message, including
RRCReconfiguration.
- Send Handover Required message from the source NG-RAN to the AMF.
2. Handover Execution:
- Decode and handle the Handover Request on the target NG-RAN.
- Process the Handover Command on the source gNB, triggering
RRCReconfiguration.
- Initiate Handover Notify after successful completion.
3 NGAP & RRC Enhancements:
- Implement NGAP encoding/decoding functions for Handover Required,
Handover Request, Handover Command, Handover Failure, and Handover
Notify (3GPP TS 38.413).
- Adds NG-RAN Status Transfer support (UL/DL) for PDCP COUNT
preservation during mobility:
- support for NGAP Uplink and Downlink RAN Status Transfer messages
(TS 38.413 §9.2.3.13-14) to enable proper PDCP COUNT value
transfer during handover or recovery: NGAP encoding/decoding for
RAN Status Transfer, PDCP helpers to extract and apply COUNT (HFN
+ SN) per DRB. This aligns with TS 38.300 §9.2.3.2.1 and TS 23.502
§4.9.1.3.3, ensuring PDCP status preservation in AM.
4. Testing:
- Introduce a Telnet command to manually trigger N2 handover using UE
ID and neighbor PCI.
- Add configuration file for testing N2 handover with a target gNB.
The pipeline is using the already existing conf files
for the source/target gNB CUs/DUs.
For the sake of simplicity, neighbour-config.conf has
been rewritten and simplified in this commit, then
adopted in this pipeline. The file was not used before.
CI: Creation of F1 Handover pipeline
In this MR we are modifying/adding all the required files (.xml, .conf,
.yml) in order to create a pipeline on Jenkins that allows us to test
OTA F1 handover.
RFSim test for 10 UEs/process
This MR adds a testcase and changes required to run 10 UEs in a single
process with RFSim
- Added deregistration for all connected UEs
- Refactored MAC/RRC instance handling
- made map_current_symbol thread safe
- made opeanir0_cfg thread safe and local
- Added 10UE/process testcase
Add SYS_NICE capability to enable setting thread priority and affinity
in rfsim5g tests. This improves execution speed in test cases with
heavier processing workloads.
RF simulator: Fix concurrency issues during new client connections
- Fix concurrency issues happening when a new client connects, sometimes
leading to a total softmodem deadlock.
- trace in 4G RAR processing to debug ci result
Speed up docker deployment in CI
- Using docker compose up --wait instead of a custom healthcheck script:
from: https://docs.docker.com/reference/cli/docker/compose/up/
--wait Wait for services to be running|healthy. Implies detached mode.
--wait-timeout Maximum duration in seconds to wait for the project to be running|healthy
- Speeding up the healthchecks by reducing the interval from 1-10s to
0.5s during start period
start_period creates a special period after the start of the container
where the healthcheck is executed every start_interval . During this
time the failures do not count towards the retries counter, but
successes change the status to healthy. This allows container to reach
healthy status much sooner.
- Using init: true to speed up docker compose down/stop
`init: true` initializes the docker container with tini or
alternative: tini is used to collect all the processes and correctly
pass the termination signal to them. This allows the docker container
to be stopped without waiting 10 seconds to kill the container
- Smallest example of this is:
services:
test-init:
image: ubuntu:jammy
command: sleep 10d
Fix concurrency issues happening when a new client connects, sometimes
leading to a total softmodem deadlock.
Key changes:
- Fix sample sending on new client connection: send the first
sample only to the newly connected client.
- Remove the --rfsimulator.hanging-workaround option
- Replace global nb_ue and Sockmutex with nb_cnx and Sockmutex
in rfsimulator_state_t for better concurrency and clarity.
This modification aims to improve health status detection by using PRACH IO as
an indicator of the gNB's status (container is marked as "healthy" when the
PRACH IO value in gNB nrL1_stats.log exceeds 0.0 dB.). The new condition accounts
for scenarios where the container may not exit or produce error codes (e.g.,
“sleep” logs or "error code overflow" messages).
- `init: true` initializes the docker container with tini or alternative - it is
used to collect all the processes and correctly pass the termination signal to
them, this allows the docker container to be stopped without waiting 10 seconds
to kill the container
- speeding up the healthchecks by reducing the interval from 1-10s to 0.5s during
start period
Co-authored-by: Bartosz Podrygajlo <bartosz.podrygajlo@openairinterface.org>
[E2 agent] E2AP README update and OAI-FlexRIC CI pipeline improvements
- E2AP README - add OSC nearRT-RIC section; update with proper FlexRIC
links, and explanations on prerequisites, as well as for xApps
- OAI-FlexRIC CI - use separate containers for xApps
- add reference files for CU-UP/CU-CP
- add logging for KPM NSSAI condition
Instead of running xApps from oai-flexric container,
create dedicated xApp containers.
In addition, modify the flexric.conf: DB_PATH doesn't exist;
DB_DIR is the correct name.
Robert Schmidt