fixed multicast updated tests

2026-07-25 16:46:25 +02:00
parent 3e0a481c13
commit 915a192b16
16 changed files with 542 additions and 75 deletions
@@ -39,7 +39,38 @@ cd Client/streamhub-qt && cmake -B build && cmake --build build

 End-to-end demo script (build + launch full stack, see header for ports/options): `./run_streamhub.sh`.

-**Streaming-chain E2E suite** (`Test/E2E/suite/`): `./run_e2e.sh [--skip-build] [--only <id>] [--cpp-coverage]` drives the full chain per scenario (`scenarios.py`) — generates typed/shaped input + both cfgs, runs MARTe2+StreamHub, records via the Go `chain-client` (live/zoom/window/trigger), and validates the recorded waveform against an analytic/fed oracle (`validate_waveform.py`: fidelity gates correctness, sine shape-fit is a gross-sanity gate + tracked metric pending Phase-A timestamp calibration). It then runs the unit suites + coverage (`collect.py`: C++ GTest, Go, Python; `--cpp-coverage` does an instrumented `--coverage` rebuild, captures with lcov restricted to `Source/*` (the `Test/` harness itself is excluded — it executes every line by construction and would just inflate the number), then restores the clean build), consolidates everything into `report_data.json` with per-field progression/regression vs the previous run and trend plots (`report_build.py`, history in `Build/x86-linux/E2E/chain/history.jsonl`), and compiles a Typst PDF (`E2E_Report.typ`). Python framework unit tests: `python3 -m unittest tests_py` (in `Test/E2E/suite/`).
+**Streaming-chain E2E suite** (`Test/E2E/suite/`):
+
+```bash
+./Test/E2E/suite/run_e2e.sh [flags]
+```
+
+Flags:
+
+| Flag | Effect |
+|---|---|
+| `--skip-build` | Skip C++ component rebuild |
+| `--only <id>` | Run a single scenario by ID |
+| `--pdf-only` | Just compile the Typst PDF report |
+| `--cpp-coverage` | Instrumented gcov rebuild + lcov capture (on by default) |
+| `--skip-coverage` | Disable the coverage pass |
+| `--skip-stress` | Skip the stress matrix |
+| `--skip-datasources` | Skip `direct` scenarios |
+| `--skip-recorder` | Skip `recorder` scenarios |
+| `--skip-debug` | Skip `debug` and `debug_pause_resume` scenarios |
+| `--skip-tcplogger` | Skip `tcplogger` scenarios |
+
+Scenario kinds (defined in `scenarios.py`):
+
+- **chain** — full streaming pipeline: MARTe2 → UDPStreamer → StreamHub → Go `chain-client` (live/zoom/window/trigger). Validates recorded waveform against analytic/fed oracle (`validate_waveform.py`: fidelity gates correctness, sine shape-fit is a gross-sanity gate + tracked metric).
+- **direct** — MARTe2 FileReader → FileWriter round-trip, validates binary output.
+- **recorder** — MARTe2 → StreamHub with history recorder, validates recorded `.bin` file.
+- **debug / debug_pause_resume** — DebugService scenarios via the Go `debugclient`.
+- **tcplogger** — TcpLogger scenarios via the Go `debugclient`.
+
+After scenarios, the suite runs unit tests + coverage (`collect.py`: C++ GTest, Go, Python; coverage uses lcov restricted to `Source/*` — the `Test/` harness is excluded), consolidates everything into `report_data.json` with per-field progression/regression vs the previous run and trend plots (`report_build.py`, history in `Build/x86-linux/E2E/chain/history.jsonl`), and compiles a Typst PDF (`E2E_Report.typ`). Artifacts go to `Build/x86-linux/E2E/chain/` (report, logs, PDF) and `/tmp/chain_e2e/` (scratch). Results are aggregated into `results.json` with XFAIL/XPASS handling for known issues.
+
+Python framework unit tests: `python3 -m unittest tests_py` (in `Test/E2E/suite/`).

 Build output goes to `Build/x86-linux/` (shared libs per component, `.ex` executables).

@@ -0,0 +1,282 @@
+# E2E Test Suite
+
+The streaming-chain end-to-end suite (`Test/E2E/suite/`) validates the full data path from
+MARTe2 real-time application through the UDPS wire protocol to StreamHub and client consumers.
+It also covers the debug/trace path (DebugService, TCPLogger) and the direct
+UDPStreamer-to-UDPStreamerClient round-trip.
+
+## Overview
+
+The suite is driven by a single orchestrator script:
+
+```bash
+source env.sh
+./Test/E2E/suite/run_e2e.sh [flags]
+```
+
+For each scenario defined in `scenarios.py`, the orchestrator:
+
+1. **Generates input data** (`gen_data.py`) — deterministic typed/shaped binary in MARTe2
+   FileReader format, plus a ground-truth dict for the validator.
+2. **Generates configs** (`gen_cfg.py`) — MARTe2 app config (LinuxTimer + FileReader + IOGAM +
+   UDPStreamer) and StreamHub config, per scenario.
+3. **Launches the server stack** — MARTe2 app + StreamHub (for chain/recorder scenarios) or
+   MARTe2 app alone (for direct/debug scenarios).
+4. **Drives mock clients** — the Go `chain-client` (chain scenarios) or `debugclient`
+   (debug/tcplogger scenarios) connects, records data, and runs behavioural checks.
+5. **Validates** (`validate_waveform.py`) — compares the recorded stream against the analytic
+   ground truth and/or the fed-reference tap file.
+6. **Renders plots** (`plots.py`) — waveform, trigger, and zoom overlay PNGs per scenario.
+7. **Runs unit tests + coverage** (`collect.py`) — C++ GTest, Go, and Python suites with
+   optional lcov C++ line coverage.
+8. **Runs stress matrix** (`stress_run.py` / `stress.py`) — capacity sweeps (signal size,
+   count, fan-out, zoom rate) with survival/liveness/RSS/latency gates.
+9. **Builds the report** (`report_build.py`) — consolidates everything into
+   `report_data.json` with regression tracking against the previous run, trend plots, and a
+   Typst PDF (`E2E_Report.typ`).
+
+---
+
+## Flags
+
+| Flag                 | Effect                                                   |
+| -------------------- | -------------------------------------------------------- |
+| `--skip-build`       | Skip C++ component rebuild                               |
+| `--only <id>`        | Run a single scenario by ID                              |
+| `--pdf-only`         | Just compile the Typst PDF report (no tests)             |
+| `--cpp-coverage`     | Instrumented gcov rebuild + lcov capture (on by default) |
+| `--skip-coverage`    | Disable the coverage pass                                |
+| `--skip-stress`      | Skip the stress matrix                                   |
+| `--skip-datasources` | Skip `direct` scenarios                                  |
+| `--skip-recorder`    | Skip `recorder` scenarios                                |
+| `--skip-debug`       | Skip `debug` and `debug_pause_resume` scenarios          |
+| `--skip-tcplogger`   | Skip `tcplogger` scenarios                               |
+
+---
+
+## Scenario Kinds
+
+### chain
+
+Full streaming pipeline: MARTe2 (FileReader -> IOGAM -> UDPStreamer) -> StreamHub -> Go
+`chain-client`. The client records the live binary stream and runs behavioural checks
+(live, zoom, window, trigger). The validator compares the recording against the analytic
+ground truth (fidelity, sine shape fit, continuity) and optionally a fed-reference tap.
+
+### direct
+
+MARTe2 FileReader -> UDPStreamer -> UDPStreamerClient -> FileWriter round-trip. Validates that
+the written binary matches the input binary (bit-exact for each signal type).
+
+### recorder
+
+MARTe2 -> UDPStreamer -> StreamHub with BinaryRecorder enabled. Validates the `.bin` file
+written to disk by the recorder against the original input.
+
+### debug / debug_pause_resume
+
+DebugService scenarios exercising FORCE, TRACE, and BREAK commands over TCP (port 8080) with
+trace telemetry on UDP (port 8081). The Go `debugclient` scripts a fixed command sequence and
+verifies real acknowledgements. The `debug_pause_resume` variant additionally verifies that
+PAUSE halts the RT loop and RESUME restarts it via live VALUE polling.
+
+### tcplogger
+
+TCPLogger delivery: verifies that a triggered DebugService event produces a log line on the
+TCPLogger TCP port (8082/9090).
+
+---
+
+## Validation Oracles
+
+Each chain scenario specifies an `oracle` mode:
+
+- **analytic** — ground truth is reconstructed from `gen_data.py`'s deterministic formulas
+  (sine, ramp, counter, time_us, time_ns). No reference file needed.
+- **fed** — a second IOGAM branch in the MARTe config taps the same signals into a FileWriter
+  ("tap file"). The validator compares recordings against this tap.
+- **both** — both oracles are applied.
+
+Per-signal checks (`validate_waveform.py`):
+
+| Check             | Description                                                                                                                                                                        |
+| ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| **Fidelity**      | Every received value within tolerance of some ground-truth value. Tolerance is 0 for raw integers, float epsilon for raw floats, `quant_step/2 + 1e-6*range` for quantised floats. |
+| **Shape**         | Sine signals (>= 8 points): least-squares fit of `a*sin(wt)+b*cos(wt)+c`. Requires correlation >= 0.99 and low normalised RMSE (relaxed by quant step).                            |
+| **Fed reference** | When `--tap` is given, each received value must also match the tap.                                                                                                                |
+| **Continuity**    | Flags inter-sample gaps > 10x median spacing. Fails when summed gap duration exceeds 5% of capture span.                                                                           |
+
+---
+
+## Client Checks
+
+The Go `chain-client` (`Test/E2E/suite/client/`) performs behavioural checks specified per
+scenario in `client_checks`:
+
+| Check     | What it verifies                                                                                |
+| --------- | ----------------------------------------------------------------------------------------------- |
+| `live`    | WebSocket connection succeeds and live binary pushes arrive with monotonic timestamps.          |
+| `zoom`    | A `zoom` WS command returns a valid binary response covering the requested time range.          |
+| `window`  | A `window` WS command returns data within the specified time bounds.                            |
+| `trigger` | A `trigger` WS command on the specified signal fires and returns data around the trigger point. |
+
+---
+
+## Stress Matrix
+
+The stress module (`stress.py` + `stress_run.py`) exercises capacity by sweeping one load axis
+at a time:
+
+| Axis               | What is scaled                                               |
+| ------------------ | ------------------------------------------------------------ |
+| Signal size        | Bytes per packet (array element count)                       |
+| Signal count       | Number of signals per source                                 |
+| Subscriber fan-out | Number of StreamHub instances subscribing to one UDPStreamer |
+| WS client count    | Parallel WebSocket clients on one StreamHub                  |
+| Zoom request rate  | Concurrent zoom queries per second per client                |
+
+Gates:
+
+- **Survival** (hard) — neither server crashed or hung.
+- **Liveness** (hard) — every client received monotonic, timestamped pushes.
+- **Peak RSS** (soft) — MARTe and StreamHub memory stayed under case ceilings.
+- **Zoom p95 latency** (soft) — round-trip zoom query latency under load.
+
+Results are written to `stress_results.json` with axis/level for scaling-curve plots.
+
+---
+
+## Artifacts
+
+| Path                                         | Content                                                             |
+| -------------------------------------------- | ------------------------------------------------------------------- |
+| `Build/x86-linux/E2E/chain/results.json`     | Per-scenario status (PASS/FAIL/SKIP/XFAIL/XPASS) + waveform metrics |
+| `Build/x86-linux/E2E/chain/report_data.json` | Full report data including regression diffs                         |
+| `Build/x86-linux/E2E/chain/history.jsonl`    | One-line-per-run headline metrics for trend tracking                |
+| `Build/x86-linux/E2E/chain/trend_*.png`      | Pass-rate / coverage / fidelity / memory trend plots                |
+| `Build/x86-linux/E2E/chain/E2E_Report.pdf`   | Compiled Typst PDF report                                           |
+| `Build/x86-linux/E2E/chain/unit_tests.json`  | Per-suite test results (GTest, Go, Python)                          |
+| `Build/x86-linux/E2E/chain/coverage.json`    | Per-language coverage percentages                                   |
+| `Build/x86-linux/E2E/chain/stress/`          | Stress matrix results                                               |
+| `Build/x86-linux/E2E/chain/hub_<id>.log`     | StreamHub stdout/stderr per scenario                                |
+| `Build/x86-linux/E2E/chain/marte_<id>.log`   | MARTe2 app stdout/stderr per scenario                               |
+| `Build/x86-linux/E2E/chain/client_<id>.log`  | Client stdout/stderr per scenario                                   |
+| `/tmp/chain_e2e/`                            | Scratch: input binaries, configs, recordings, metrics, plots        |
+
+---
+
+## XFAIL / XPASS Handling
+
+Scenarios may carry a `known_issue` marker (a human-readable string describing a documented,
+not-yet-fixed chain gap). When present:
+
+- A raw **FAIL** is reclassified as **XFAIL** (expected failure) — does not break the green
+  baseline.
+- A raw **PASS** becomes **XPASS** (unexpectedly fixed) — surfaced as a failure to prompt
+  removal of the stale marker.
+
+Overall status is PASS when there are no hard FAILs and no XPASSes.
+
+---
+
+## Framework Files
+
+| File                   | Role                                                            |
+| ---------------------- | --------------------------------------------------------------- |
+| `run_e2e.sh`           | Top-level orchestrator (build, run scenarios, coverage, report) |
+| `scenarios.py`         | Declarative scenario matrix + validation                        |
+| `gen_data.py`          | Deterministic input binary generator                            |
+| `gen_cfg.py`           | MARTe2 + StreamHub config generator                             |
+| `validate_waveform.py` | Waveform comparison (fidelity, shape, continuity)               |
+| `plots.py`             | Per-scenario PNG figure renderer                                |
+| `collect.py`           | Unit test runner + coverage collector (GTest, Go, Python, lcov) |
+| `report_build.py`      | Report data consolidator + trend plots + history                |
+| `stress.py`            | Declarative stress case matrix                                  |
+| `stress_run.py`        | Stress matrix orchestrator                                      |
+| `proc_perf.py`         | Live-process CPU/RSS snapshot from `/proc`                      |
+| `E2E_Report.typ`       | Typst template for the PDF report                               |
+| `tests_py.py`          | Python framework unit tests (`python3 -m unittest tests_py`)    |
+| `client/main.go`       | Go chain-client (live record + zoom/window/trigger checks)      |
+| `debugclient/main.go`  | Go debug/tcplogger client (command scripting + verification)    |
+
+---
+
+## Scenario Matrix
+
+| ID                            | Kind               | Description                                                                              |
+| ----------------------------- | ------------------ | ---------------------------------------------------------------------------------------- |
+| `s01_scalar_uint32`           | chain              | Single uint32 scalar counter, Strict unicast (type fidelity)                             |
+| `s02_array_float32_fullarray` | chain              | 100-elem float32 array, FullArray time mode, uint64 ns time array                        |
+| `s03_quant_uint16`            | chain              | float32 scalar quantised to uint16 over [-5,5], Strict unicast                           |
+| `s04_int8_scalar`             | chain              | int8 scalar counter, type fidelity                                                       |
+| `s05_uint8_scalar`            | chain              | uint8 scalar counter, type fidelity                                                      |
+| `s06_int16_scalar`            | chain              | int16 scalar ramp, type fidelity                                                         |
+| `s07_uint16_scalar`           | chain              | uint16 scalar ramp, type fidelity                                                        |
+| `s08_int32_scalar`            | chain              | int32 scalar counter, type fidelity                                                      |
+| `s09_int64_scalar`            | chain              | int64 scalar counter, type fidelity                                                      |
+| `s10_uint64_scalar`           | chain              | uint64 scalar counter, type fidelity                                                     |
+| `s11_float64_scalar`          | chain              | float64 scalar sine 5 Hz (double-precision path)                                         |
+| `s12_f32_arr8`                | chain              | float32 8-elem array sine 5 Hz                                                           |
+| `s13_f32_arr32`               | chain              | float32 32-elem array sine 10 Hz                                                         |
+| `s14_f64_arr64`               | chain              | float64 64-elem array ramp                                                               |
+| `s15_i16_arr16`               | chain              | int16 16-elem array counter                                                              |
+| `s16_f32_arr256`              | chain              | float32 256-elem array sine 5 Hz (large frame)                                           |
+| `s17_lastsample`              | chain              | float32 8-elem LastSample, uint64 ns scalar anchor                                       |
+| `s18_firstsample`             | chain              | float32 8-elem FirstSample, uint32 us scalar anchor                                      |
+| `s19_fullarray_f64`           | chain              | float64 50-elem FullArray sine 5 Hz, uint64 ns time                                      |
+| `s20_quant_uint8`             | chain              | float32 scalar quant uint8 [-1,1] sine 5 Hz                                              |
+| `s21_quant_int8`              | chain              | float32 scalar quant int8 [-10,10] sine 5 Hz                                             |
+| `s22_quant_int16`             | chain              | float32 scalar quant int16 [-100,100] ramp                                               |
+| `s23_quant_f64_arr`           | chain              | float64 16-elem quant uint16 [-2,2] sine 5 Hz                                            |
+| `s24_accumulate`              | chain              | float32 scalar sine 5 Hz, Accumulate @50 Hz refresh                                      |
+| `s25_decimate4`               | chain              | float32 scalar sine 5 Hz, Decimate ratio 4                                               |
+| `s26_decimate10_arr`          | chain              | float32 8-elem counter, Decimate ratio 10                                                |
+| `s27_frag_f64_128`            | chain              | float64 128-elem ramp, MaxPayload 512 (fragmented)                                       |
+| `s28_frag_f32_100`            | chain              | float32 100-elem sine 5 Hz, MaxPayload 256 (fragmented)                                  |
+| `s29_mcast_scalar`            | chain              | multicast float32 scalar sine 5 Hz                                                       |
+| `s30_mcast_arr_fullarray`     | chain              | multicast float32 32-elem FullArray sine 5 Hz                                            |
+| `s31_two_src`                 | chain              | two unicast sources: float32 sine + uint32 counter                                       |
+| `s32_three_src`               | chain              | three unicast sources: int16 ramp / float64 sine / uint8 counter                         |
+| `s33_dec_arr_quant`           | chain              | Decimate 2 + 16-elem quant uint16 sine 5 Hz                                              |
+| `s34_acc_fullarray`           | chain              | Accumulate @100 Hz: accumulated scalar + 32-elem FullArray sine passenger                |
+| `s35_mcast_decimate`          | chain              | multicast + Decimate ratio 5, float32 scalar sine 5 Hz                                   |
+| `s36_big_frag_dec`            | chain              | float64 64-elem ramp, MaxPayload 256 + Decimate 4                                        |
+| `s37_trig_ramp_i32`           | chain              | trigger on int32 ramp scalar                                                             |
+| `s38_trig_f64_sine`           | chain              | trigger on float64 sine 5 Hz scalar                                                      |
+| `s39_uint8_arr32`             | chain              | uint8 32-elem array counter (wrap fidelity)                                              |
+| `s40_int8_arr16`              | chain              | int8 16-elem array counter (wrap fidelity)                                               |
+| `s41_f32_unit`                | chain              | float32 scalar ramp with Unit=V                                                          |
+| `s42_f64_counter`             | chain              | float64 scalar counter (large integer values)                                            |
+| `s43_fullarray_quant`         | chain              | float32 16-elem FullArray quant uint16 sine 5 Hz                                         |
+| `s44_window_check`            | chain              | float32 sine 5 Hz scalar, window time-range check                                        |
+| `s45_decimate_multisig`       | chain              | Decimate ratio 2 over a 2-signal source                                                  |
+| `s46_accumulate_arr`          | chain              | Accumulate @200 Hz: accumulated scalar sine + 16-elem array passenger                    |
+| `s47_mcast_multisrc`          | chain              | multicast, two sources (scalar each)                                                     |
+| `s48_f64_arr_big_payload`     | chain              | float64 100-elem ramp, MaxPayload 65490 (single frame)                                   |
+| `s49_mixed_quant_raw`         | chain              | one source: quant uint8 sine + raw float32 sine                                          |
+| `s50_trig_quant`              | chain              | trigger on quantised uint16 sine 10 Hz                                                   |
+| `s51_8x1msps_100hz`           | chain              | 8x float32 10k-elem arrays @1 MSps, FirstSample, 100 Hz packets (~32 MB/s)               |
+| `s52_direct_unicast`          | direct             | Direct UDPStreamer->UDPStreamerClient round-trip, unicast                                |
+| `s53_direct_multicast`        | direct             | Direct UDPStreamer->UDPStreamerClient round-trip, multicast                              |
+| `s54_recorder`                | recorder           | StreamHub BinaryRecorder disk-output round-trip                                          |
+| `s55_debug_force_trace_break` | debug              | DebugService FORCE/TRACE/BREAK over real TCP 8080 + UDP 8081                             |
+| `s56_tcplogger_delivery`      | tcplogger          | TCPLogger delivers a log line for a triggered DebugService event                         |
+| `s57_debug_pause_resume`      | debug_pause_resume | DebugService PAUSE/RESUME halts and resumes the RT loop, verified via live VALUE polling |
+
+---
+
+## Coverage Goals
+
+The chain scenario matrix is a curated covering set: every configurable UDPStreamer option
+value appears in at least one scenario:
+
+- **All 10 MARTe2 types**: int8, uint8, int16, uint16, int32, uint32, int64, uint64, float32, float64
+- **Scalar and array shapes**: elements 1, 8, 16, 32, 50, 64, 100, 128, 256, 1000, 10000
+- **All four TimeModes**: PacketTime, FullArray, FirstSample, LastSample
+- **All five QuantizedTypes**: none, uint8, int8, uint16, int16
+- **All three PublishingModes**: Strict, Accumulate, Decimate
+- **Both network modes**: unicast and multicast
+- **Fragmentation**: small MaxPayloadSize forcing multi-fragment datagrams
+- **Multi-source**: 1, 2, and 3 independent UDPStreamer feeds into one StreamHub
+- **High-risk interactions**: decimate+quant+array, accumulate+fullarray, multicast+decimate,
+  fragmentation+decimate, mixed quant+raw signals
@@ -8,7 +8,9 @@ thread.
 ## Key Features

 - **Zero-copy RT path** — `Synchronise()` only locks, copies signal memory, and posts a semaphore.
- **Single-client model** — one client at a time; a new CONNECT replaces the previous session.
+- **Unicast and multicast** — unicast (default): single client at a time, new CONNECT replaces
+  the previous session. Multicast: multiple clients receive data simultaneously by joining
+  a multicast group; control traffic uses a TCP listener.
 - **Packet fragmentation** — large payloads are split into ≤ `MaxPayloadSize`-byte datagrams,
  each with a header carrying fragment index and total count so the client can reassemble them.
 - **Signal quantization** — `float32`/`float64` signals can be linearly quantized to
@@ -16,6 +18,8 @@ thread.
 - **Temporal arrays** — signals with `NumberOfElements > 1` can carry per-sample time
  metadata via `TimeMode` and `TimeSignal`, enabling high-frequency burst transmission
  (e.g. 1 000 samples per RT cycle at 1 MSps).
+- **Publishing modes** — `Strict` (one packet per RT cycle), `Accumulate` (batch N snapshots
+  then flush on size or time limit), `Decimate` (send every Nth cycle).

 ---

@@ -26,10 +30,22 @@ thread.
    Class           = UDPStreamer

    // Network
-    Port            = 44500        // UDP port the server listens on (default: 44500)
+    Port            = 44500        // UDP port (unicast) or TCP control port (multicast)
    MaxPayloadSize  = 1400         // Maximum bytes per UDP datagram (default: 1400)
                                   //   Must be > 17 (header size). Tune for MTU.

+    // Multicast (optional — omit for unicast mode)
+    MulticastGroup  = "239.0.0.1"  // IPv4 multicast address (224.0.0.0/4)
+    Interface       = "eth0"       // Multicast-bound interface (mandatory when MulticastGroup is set)
+    DataPort        = 44501        // UDP port for multicast DATA (default: Port+1)
+
+    // Publishing mode (optional)
+    PublishingMode  = "Strict"     // Strict | Accumulate | Decimate
+    // For Accumulate mode:
+    MinRefreshRate  = 120.0        // Flush frequency in Hz (required for Accumulate)
+    // For Decimate mode:
+    Ratio           = 10           // Send 1 packet every N RT cycles (required for Decimate)
+
    // Background thread (optional)
    CPUMask         = 0x2          // CPU affinity mask for the network thread
    StackSize       = 1048576      // Stack size in bytes (default: 1 MiB)
@@ -67,11 +83,17 @@ thread.
 ### Top-level Parameters

 | Parameter        | Type   | Default          | Description                                                                 |
-| ---------------- | ------ | --------- | ------------------------------------------- |
-| `Port`           | uint16 | 44500     | UDP server port                             |
+| ---------------- | ------ | ---------------- | --------------------------------------------------------------------------- |
+| `Port`           | uint16 | 44500            | UDP server port (unicast) or TCP control port (multicast). Values ≤ 1024 produce a warning. |
 | `MaxPayloadSize` | uint32 | 1400             | Max payload bytes per UDP datagram (min 18)                                 |
-| `CPUMask`        | uint32 | 0 (any)   | Background thread CPU affinity              |
-| `StackSize`      | uint32 | 1 048 576 | Background thread stack size in bytes       |
+| `MulticastGroup` | string | *(absent)*       | IPv4 multicast address (e.g. `"239.0.0.1"`). Must be in 224.0.0.0/4. Absent or empty = unicast mode. |
+| `Interface`      | string | *(absent)*       | Network interface for multicast binding (e.g. `"eth0"`). **Mandatory** when `MulticastGroup` is set. |
+| `DataPort`       | uint16 | Port+1           | UDP port for multicast DATA datagrams. Ignored in unicast mode.             |
+| `PublishingMode` | string | Strict           | `Strict`: send every RT cycle. `Accumulate`: batch until size/time limit. `Decimate`: send every Nth cycle. |
+| `MinRefreshRate` | float64| —                | Flush frequency in Hz. **Required** when `PublishingMode` = `Accumulate`.   |
+| `Ratio`          | uint32 | —                | Send 1 packet every `Ratio` RT cycles. **Required** when `PublishingMode` = `Decimate`. |
+| `CPUMask`        | uint32 | 0xFFFFFFFF (any) | Background thread CPU affinity bitmask                                      |
+| `StackSize`      | uint32 | MARTe2 default   | Background thread stack size in bytes                                       |

 ### Per-signal Parameters

@@ -113,6 +135,62 @@ wire_value = (uint16)(normalized × 65535)

 ---

+## Network Modes
+
+### Unicast (default)
+
+The server opens a single UDP socket on `Port`. The client initiates the session by sending a
+CONNECT packet to that port. The server replies with a CONFIG packet on the same socket and
+subsequently sends DATA packets directly to the client's address. One client at a time; a new
+CONNECT evicts the previous client.
+
+### Multicast
+
+Enabled by setting `MulticastGroup` to a valid IPv4 multicast address (224.0.0.0/4).
+The `Interface` parameter is **mandatory** and specifies the network interface to bind.
+
+The server opens a TCP listener on `Port` for control traffic and a UDP socket aimed at
+`MulticastGroup:DataPort` for data traffic. The client:
+
+1. Connects to `Port` via TCP and sends a CONNECT packet.
+2. Receives the CONFIG packet over TCP.
+3. Joins the multicast group (`MulticastGroup:DataPort`) to receive DATA packets.
+
+Multiple clients may receive data simultaneously by joining the same group.
+
+---
+
+## Publishing Modes
+
+### Strict (default)
+
+Sends one DATA packet for every `Synchronise()` call (every RT cycle). Simplest and lowest
+latency.
+
+### Accumulate
+
+Batches multiple RT-cycle snapshots into a single DATA packet. All signals (scalars and arrays)
+are accumulated: one full snapshot per RT cycle. The batch is flushed when either:
+
+- **Size condition**: adding one more sample would exceed `MaxPayloadSize`.
+- **Time condition**: `1/MinRefreshRate` seconds have elapsed since the last flush.
+
+The maximum batch count is computed automatically from `MaxPayloadSize` and the total wire size
+of all signals. Scalar signals with `Unit="us"` or `"ns"` are auto-promoted as the per-sample
+FullArray time reference for all other scalars.
+
+Requires `MinRefreshRate` (Hz) to be set.
+
+### Decimate
+
+Sends one DATA packet every `Ratio` RT cycles, dropping intermediate cycles. Only the most
+recent snapshot at the Nth cycle is sent.
+
+Requires `Ratio` (≥ 1) to be set. `Ratio = 1` is equivalent to `Strict` mode (a warning is
+logged).
+
+---
+
 ## Broker

 UDPStreamer uses `MemoryMapSynchronisedOutputBroker` for output signals. This broker is
@@ -151,7 +229,7 @@ PrepareNextState()          ← opens UDP server socket, starts background threa

 ---

-## Example: minimal scalar streaming
+## Example: minimal scalar streaming (unicast)

 ```
 +Data = {
@@ -168,6 +246,26 @@ PrepareNextState()          ← opens UDP server socket, starts background threa
 }
 ```

+## Example: multicast with accumulation
+
+```
+Streamer = {
+    Class            = UDPStreamer
+    Port             = 44500           // TCP control port
+    MulticastGroup   = "239.0.0.1"     // Enables multicast mode
+    Interface        = "eth0"          // Mandatory for multicast
+    DataPort         = 44501           // UDP data port (default: Port+1)
+    MaxPayloadSize   = 1400
+    PublishingMode   = "Accumulate"
+    MinRefreshRate   = 60.0            // Flush at least 60 times/s
+
+    Signals = {
+        Time    = { Type = uint32; Unit = "us" }
+        Voltage = { Type = float32; Unit = "V"; RangeMin = -10.0; RangeMax = 10.0; QuantizedType = uint16 }
+    }
+}
+```
+
 ## Example: high-frequency burst

 ```
@@ -198,3 +296,19 @@ With `MaxPayloadSize = 1400`, a single 1000-element float32 signal produces:
 payload = 8 B (HRT timestamp) + 4 B (T0/uint32) + 4000 B (float32×1000) = 4012 B
 fragments = ceil(4012 / 1383) = 3
 ```
+
+## Example: decimated output
+
+```
+Streamer = {
+    Class          = UDPStreamer
+    Port           = 44500
+    PublishingMode = "Decimate"
+    Ratio          = 10                // Send 1 packet every 10 RT cycles
+
+    Signals = {
+        Time     = { Type = uint32; Unit = "us" }
+        Position = { Type = float64; Unit = "mm" }
+    }
+}
+```
@@ -1,48 +1,48 @@
 ../../../..//Build/x86-linux/Components/DataSources/UDPStreamer/UDPStreamer.o: UDPStreamer.cpp \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/AdvancedErrorManagement.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassProperties.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GeneralDefinitions.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TypeCharacteristics.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/ErrorType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/CompilerTypes.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/Architecture/x86_gcc/CompilerTypes.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/GeneralDefinitions.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/FractionalInteger.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TypeCharacteristics.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitBoolean.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TemplateParametersVerificator.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/CompilerTypes.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitRange.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TypeCharacteristics.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamString.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GeneralDefinitions.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TypeCharacteristics.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/GeneralDefinitions.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HeapManager.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HeapI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/ErrorManagement.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/ErrorInformation.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/ErrorType.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitBoolean.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitRange.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GeneralDefinitions.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StreamI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/TimeoutType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HighResolutionTimer.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/TimeStamp.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Architecture/x86_gcc/HighResolutionTimerA.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/CompilerTypes.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/HighResolutionTimer.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../HighResolutionTimer.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/HighResolutionTimerCalibrator.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../GeneralDefinitions.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/TimeStamp.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamMemoryReference.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/CharBuffer.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitBoolean.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/ErrorManagement.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/BufferedStreamI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/TimeoutType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/AnyType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassProperties.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/FractionalInteger.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassRegistryDatabase.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GlobalObjectsDatabase.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GlobalObjectI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/StandardHeap.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../HeapI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../ErrorManagement.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../GeneralDefinitions.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../Generic/StandardHeap_Generic.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/FastPollingMutexSem.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Atomic.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Architecture/x86_gcc/AtomicA.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/ErrorManagement.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Sleep.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassRegistryItem.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/CString.h \
@@ -53,7 +53,6 @@
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BasicType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/FractionalInteger.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitRange.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitBoolean.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/ZeroTerminatedArray.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/LinkedListable.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/LinkedListHolderT.h \
@@ -70,17 +69,18 @@
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StaticListHolder.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/Matrix.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/Vector.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HeapManager.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HeapI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/MemoryOperationsHelper.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/FormatDescriptor.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/IOBuffer.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/CharBuffer.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StreamI.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StringHelper.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamStringIOBuffer.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/AdvancedErrorManagement.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassProperties.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamMemoryReference.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L4Configuration/ConfigurationDatabase.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L4Configuration/AnyObject.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/Object.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StringHelper.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/StructuredDataI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/AnyType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/CLASSREGISTER.h \
@@ -104,8 +104,6 @@
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/StructuredDataI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L4Configuration/TypeConversion.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/Vector.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamString.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamStringIOBuffer.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedThreadI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedServiceMethodBinderI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/ExecutionInfo.h \
@@ -116,18 +114,12 @@
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitSet.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedServiceMethodBinderT.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HighResolutionTimer.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/MemoryMapSynchronisedOutputBroker.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/MemoryMapOutputBroker.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/MemoryMapBroker.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/BrokerI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/DataSourceI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/StatefulI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/ExecutableI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Sleep.h \
 UDPStreamer.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedServiceMethodBinderI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L1Portability/EventSem.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/MemoryDataSourceI.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/DataSourceI.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/StatefulI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/SingleThreadService.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedServiceI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedThreadI.h \
@@ -141,5 +133,6 @@
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HandleI.h \
 /home/martino/workspace/MARTe2/Source/Core/FileSystem/L1Portability/Environment/Linux/SocketCore.h \
 /home/martino/workspace/MARTe2/Source/Core/FileSystem/L1Portability/BasicUDPSocket.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Sleep.h \
 /home/martino/workspace/MARTe2/Source/Core/FileSystem/L1Portability/InternetHost.h \
 ../../../..//Common/UDP/UDPSProtocol.h
@@ -1,48 +1,48 @@
 UDPStreamer.o: UDPStreamer.cpp \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/AdvancedErrorManagement.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassProperties.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GeneralDefinitions.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TypeCharacteristics.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/ErrorType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/CompilerTypes.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/Architecture/x86_gcc/CompilerTypes.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/GeneralDefinitions.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/FractionalInteger.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TypeCharacteristics.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitBoolean.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TemplateParametersVerificator.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/CompilerTypes.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitRange.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TypeCharacteristics.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamString.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GeneralDefinitions.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/TypeCharacteristics.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/GeneralDefinitions.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HeapManager.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HeapI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/ErrorManagement.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/ErrorInformation.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/ErrorType.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitBoolean.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitRange.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GeneralDefinitions.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StreamI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/TimeoutType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HighResolutionTimer.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/TimeStamp.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Architecture/x86_gcc/HighResolutionTimerA.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/CompilerTypes.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/HighResolutionTimer.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../HighResolutionTimer.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/HighResolutionTimerCalibrator.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../GeneralDefinitions.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/TimeStamp.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamMemoryReference.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/CharBuffer.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitBoolean.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/ErrorManagement.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/BufferedStreamI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/TimeoutType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/AnyType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassProperties.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/FractionalInteger.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassRegistryDatabase.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GlobalObjectsDatabase.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/GlobalObjectI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/StandardHeap.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../HeapI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../ErrorManagement.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../../GeneralDefinitions.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Environment/Linux/../Generic/StandardHeap_Generic.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/FastPollingMutexSem.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Atomic.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Architecture/x86_gcc/AtomicA.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/ErrorManagement.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Sleep.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassRegistryItem.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/CString.h \
@@ -53,7 +53,6 @@ UDPStreamer.o: UDPStreamer.cpp \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BasicType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/FractionalInteger.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitRange.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitBoolean.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/ZeroTerminatedArray.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/LinkedListable.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/LinkedListHolderT.h \
@@ -70,17 +69,18 @@ UDPStreamer.o: UDPStreamer.cpp \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StaticListHolder.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/Matrix.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/Vector.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HeapManager.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HeapI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/MemoryOperationsHelper.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/FormatDescriptor.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/IOBuffer.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/CharBuffer.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StreamI.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StringHelper.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamStringIOBuffer.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/AdvancedErrorManagement.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/ClassProperties.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamMemoryReference.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L4Configuration/ConfigurationDatabase.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L4Configuration/AnyObject.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/Object.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/StringHelper.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/StructuredDataI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/AnyType.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/CLASSREGISTER.h \
@@ -104,8 +104,6 @@ UDPStreamer.o: UDPStreamer.cpp \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L2Objects/StructuredDataI.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L4Configuration/TypeConversion.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/Vector.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamString.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L3Streams/StreamStringIOBuffer.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedThreadI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedServiceMethodBinderI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/ExecutionInfo.h \
@@ -116,18 +114,12 @@ UDPStreamer.o: UDPStreamer.cpp \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L0Types/BitSet.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedServiceMethodBinderT.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HighResolutionTimer.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/MemoryMapSynchronisedOutputBroker.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/MemoryMapOutputBroker.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/MemoryMapBroker.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/BrokerI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/DataSourceI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/StatefulI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/ExecutableI.h \
- /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Sleep.h \
 UDPStreamer.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedServiceMethodBinderI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L1Portability/EventSem.h \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/MemoryDataSourceI.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/DataSourceI.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L5GAMs/StatefulI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/SingleThreadService.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedServiceI.h \
 /home/martino/workspace/MARTe2/Source/Core/Scheduler/L3Services/EmbeddedThreadI.h \
@@ -141,5 +133,6 @@ UDPStreamer.o: UDPStreamer.cpp \
 /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/HandleI.h \
 /home/martino/workspace/MARTe2/Source/Core/FileSystem/L1Portability/Environment/Linux/SocketCore.h \
 /home/martino/workspace/MARTe2/Source/Core/FileSystem/L1Portability/BasicUDPSocket.h \
+ /home/martino/workspace/MARTe2/Source/Core/BareMetal/L1Portability/Sleep.h \
 /home/martino/workspace/MARTe2/Source/Core/FileSystem/L1Portability/InternetHost.h \
 ../../../..//Common/UDP/UDPSProtocol.h
@@ -111,6 +111,7 @@ public:
     *  - ServerAddr      (char*)  Server IPv4 address. Required.
     *  - Port            (uint16) Server UDP port (unicast) or TCP listen port (multicast). Required.
     *  - MulticastGroup  (char*)  IPv4 multicast address; presence enables multicast mode.
+     *  - Interface       (char*)  Network interface for multicast join (e.g. "lo"). Required when MulticastGroup is set.
     *  - DataPort        (uint16) UDP multicast data port (defaults to Port+1).
     *  - SilenceTimeout  (uint32) Seconds of no data before reconnect. Default 5.
     *  - ReconnectDelay  (uint32) Seconds to wait between reconnect attempts. Default 2.
@@ -11,8 +11,10 @@
 #include "MemoryOperationsHelper.h"
 #include "StreamString.h"

+#include <arpa/inet.h>
 #include <poll.h>
 #include <sys/select.h>
+#include <sys/socket.h>

 namespace MARTe {

@@ -125,9 +127,17 @@ bool UDPSServer::Start() {
    if (ok) {
      tcpListener.SetBlocking(false);
    }
-    // UDP data socket connected to multicast group
+    // UDP data socket connected to multicast group.
+    // Set IP_MULTICAST_IF so outgoing datagrams leave on the specified
+    // interface rather than whichever the kernel routing table picks.
    ok &= dataSocket.Open();
-    ok &= dataSocket.Join(multicastGroup.Buffer(), interface.Buffer());
+    if (ok) {
+      struct in_addr localIf;
+      localIf.s_addr = inet_addr(interface.Buffer());
+      int fd = static_cast<int>(dataSocket.GetWriteHandle());
+      ok = (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
+                       &localIf, static_cast<socklen_t>(sizeof(localIf))) == 0);
+    }
    ok &= dataSocket.Connect(multicastGroup.Buffer(), dataPort);
    if (!ok) {
      REPORT_ERROR_STATIC(
@@ -424,6 +424,7 @@ $TestApp = {
            Port = 44500
            MulticastGroup = "239.0.0.1"
            DataPort = 44503
+            Interface = "127.0.0.1"
            MaxPayloadSize = 1400
            PublishingMode = "Accumulate"
            MinRefreshRate = 100
@@ -279,6 +279,7 @@ $App = {
            Port = 44500
            MulticastGroup = "239.0.0.1"
            DataPort = 44503
+            Interface = "127.0.0.1"
            MaxPayloadSize = 1400
            PublishingMode = "Accumulate"
            MinRefreshRate = 100
@@ -411,6 +411,7 @@ $App = {
      Port = 44500
      MulticastGroup = "239.0.0.1"
      DataPort = 44503
+      Interface = "127.0.0.1"
      MaxPayloadSize = 1400
      PublishingMode = "Accumulate"
      MinRefreshRate = 100
@@ -64,6 +64,7 @@ $E2EMulticastTest = {
            Port = 44600
            MulticastGroup = "239.0.0.1"
            DataPort = 44610
+            Interface = "127.0.0.1"
            MaxPayloadSize = 65507
            PublishingMode = "Strict"
            Signals = {
@@ -17,6 +17,8 @@ expected, not an error.
 """
 import argparse
 import os
+import re
+import subprocess
 import sys

 sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
@@ -25,6 +27,41 @@ import scenarios as S  # noqa: E402
 PRODUCER_HZ = 1000      # LinuxTimer frequency (Hz)


+def _iface_to_ip(name):
+    """Resolve a network interface name (e.g. ``"wlan0"``) to its first IPv4
+    address via ``ip -4 addr show <name>``.  Returns ``"127.0.0.1"`` on failure."""
+    try:
+        out = subprocess.check_output(
+            ["ip", "-4", "addr", "show", name],
+            stderr=subprocess.DEVNULL, text=True)
+        m = re.search(r"inet\s+(\d+\.\d+\.\d+\.\d+)", out)
+        if m:
+            return m.group(1)
+    except (subprocess.CalledProcessError, FileNotFoundError, OSError):
+        pass
+    return "127.0.0.1"
+
+
+def _mcast_interface_ip(group):
+    """Return the IPv4 address of the OS-selected interface for a multicast
+    group.  MARTe2's ``BasicUDPSocket::Join`` expects an IP address (passed to
+    ``inet_addr``), not an interface name.
+
+    Uses ``ip route get <group>`` to find the outgoing device, then resolves
+    its IP.  Falls back to ``"127.0.0.1"`` if the route or device lookup fails.
+    """
+    try:
+        out = subprocess.check_output(
+            ["ip", "route", "get", group],
+            stderr=subprocess.DEVNULL, text=True)
+        m = re.search(r"dev\s+(\S+)", out)
+        if m:
+            return _iface_to_ip(m.group(1))
+    except (subprocess.CalledProcessError, FileNotFoundError, OSError):
+        pass
+    return "127.0.0.1"
+
+
 def _ndims(elements):
    return 0 if elements == 1 else 1

@@ -78,6 +115,8 @@ def _streamer_block(src, scenario):
    if scenario["network"] == "multicast":
        parts.append(f'MulticastGroup = "{src["multicast_group"]}"')
        parts.append(f"DataPort = {src['data_port']}")
+        iface = src.get("interface") or _mcast_interface_ip(src["multicast_group"])
+        parts.append(f'Interface = "{iface}"')
    sigs = " ".join(_streamer_sig(sig) for sig in s)
    return (f"        +Streamer_{src['id']} = {{ Class = UDPStreamer "
            f"{' '.join(parts)} Signals = {{ {sigs} }} }}")