From 4f4cb4757c244157e21d21c87fa178e0b5ccb09e Mon Sep 17 00:00:00 2001 From: Guido Casati Date: Fri, 12 Jan 2024 16:32:34 +0100 Subject: [PATCH] Extended E1 design documentation - provided insights on the messages flow with requests towards northbound --- doc/E1-design.md | 36 +++++++++++++++++++++++++++++++----- 1 file changed, 31 insertions(+), 5 deletions(-) diff --git a/doc/E1-design.md b/doc/E1-design.md index 334ddeea52..e80c431029 100644 --- a/doc/E1-design.md +++ b/doc/E1-design.md @@ -45,11 +45,37 @@ sequenceDiagram Note over c: Execute rrc_gNB_process_e1_bearer_context_release_cplt() ``` -The files that implement the callback towards these handlers are in -- `cucp_cuup_direct.c`: integrated CU (for CP=>UP messages) -- `cucp_cuup_e1ap.c`: E1 split mode (for CP=>UP messages) -- `cuup_cucp_direct.c`: integrated CU (for UP=>CP messages) -- `cuup_cucp_e1ap.c`: E1 split mode (for UP=>CP messages) +The implementation of callbacks towards these handlers is distributed across the following file, depending on the operating mode: + +| Mode | CP=>UP messages |UP=>CP messages | +| --------------| --------------------|--------------------| +| Integrated CU | `cucp_cuup_direct.c`|`cuup_cucp_direct.c`| +| E1 Split | `cucp_cuup_e1ap.c` |`cuup_cucp_e1ap.c` | + +As long as concerns E1 Interface Management Procedures, the code flow of request messages towards northbound looks like this: + +```mermaid +sequenceDiagram + participant r as RRC + participant c as CUCP + participant u as CUUP + + Note over u: E1AP_CUUP_task (SCTP Handler) + Note over u: ASN1 encoder + u->>c: e.g. E1 Setup Request (SCTP) + Note over c: E1AP_CUCP_task (SCTP Handler) + Note over c: ASN1 decoder + c->>r: E1AP_SETUP_REQ (ITTI) + Note over r: TASK_RRC_GNB (RRC Handler) + r->>c: E1AP_SETUP_RESP (ITTI) + Note over c: E1AP_CUCP_task (E1AP Callback) + Note over c: ASN1 encoder + + c->>u: e.g. E1 Setup Response/Failure + Note over u: E1AP_CUUP_task (SCTP Handler) + Note over u: ASN1 decoder +``` + # 2. Running the E1 Split