diff --git a/CALL-ALERT-PATCH.md b/CALL-ALERT-PATCH.md
new file mode 100644
index 00000000..2ba28247
--- /dev/null
+++ b/CALL-ALERT-PATCH.md
@@ -0,0 +1,53 @@
+# P25 Call Alert (TSBK 0x1F) Decoding
+
+## Summary
+
+Adds proper decoding of P25 TSBK opcode 0x1F (Call Alert) to trunk-recorder.
+Previously this was a stub that only logged a debug message and discarded the message.
+Now it extracts source/destination unit IDs, sets the message type, and flows through
+the plugin system like all other unit events.
+
+## Changes
+
+### `trunk-recorder/systems/parser.h`
+Added `CALL_ALERT = 18` to the `MessageType` enum.
+
+### `trunk-recorder/systems/p25_parser.cc`
+Replaced the stub with real decoding:
+- Source Unit ID extracted from bits 16–39: `bitset_shift_mask(tsbk, 16, 0xffffff)`
+- Target Unit ID extracted from bits 40–63: `bitset_shift_mask(tsbk, 40, 0xffffff)`
+- Sets `message.message_type = CALL_ALERT`, `message.source`, and `message.talkgroup`
+- Logs at **info** level: `tsbk1f\tCall Alert\tSource Unit: <src>\tTarget Unit: <dst>`
+
+Bit layout reference (from OP25):
+```
+args = dst << 24 | src   →   bits[16:39] = src, bits[40:63] = dst
+```
+
+### `trunk-recorder/plugin_manager/plugin_api.h`
+Added virtual method to the plugin API with a default no-op — fully backward compatible
+with existing plugins that don't implement it:
+```cpp
+virtual int unit_call_alert(System *sys, long source_id, long talkgroup) { return 0; };
+```
+
+### `trunk-recorder/plugin_manager/plugin_manager.h`
+Declared `plugman_unit_call_alert(System *system, long source_id, long talkgroup)`.
+
+### `trunk-recorder/plugin_manager/plugin_manager.cc`
+Implemented `plugman_unit_call_alert()` — iterates running plugins and calls
+`plugin->api->unit_call_alert()` on each, matching the pattern of all other unit events.
+
+### `trunk-recorder/monitor_systems.cc`
+- Added `unit_call_alert()` function that calls `plugman_unit_call_alert()`
+- Added `case CALL_ALERT:` to the message dispatch switch
+
+## Built Image
+
+```
+trunk-recorder:call-alert
+```
+
+Built from `ghcr.io/trunk-reporter/trunk-recorder:latest` as runtime base,
+with the patched `trunk-recorder` binary replacing `/usr/local/bin/trunk-recorder`.
+Dockerfile: `Dockerfile.call-alert`
diff --git a/Dockerfile.call-alert b/Dockerfile.call-alert
new file mode 100644
index 00000000..1c0dc0fb
--- /dev/null
+++ b/Dockerfile.call-alert
@@ -0,0 +1,92 @@
+# Build stage: reuse trunk-reporter's pre-built runtime as base,
+# then compile only trunk-recorder from our patched source.
+FROM ghcr.io/trunk-reporter/trunk-recorder:latest AS runtime_base
+
+FROM ubuntu:24.04 AS builder
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update && apt-get -y upgrade && \
+    apt-get install --no-install-recommends -y \
+        build-essential ca-certificates cmake curl git \
+        gnuradio-dev gr-osmosdr \
+        libosmosdr-dev libairspy-dev libairspyhf-dev libbladerf-dev \
+        libboost-all-dev libcurl4-openssl-dev libfreesrp-dev \
+        libgmp-dev libhackrf-dev libmirisdr-dev liborc-0.4-dev \
+        libpthread-stubs0-dev librtlsdr-dev libsndfile1-dev \
+        libsoapysdr-dev libssl-dev libuhd-dev \
+        libusb-dev libusb-1.0-0-dev libxtrx-dev \
+        pkg-config wget python3-six ffmpeg && \
+    rm -rf /var/lib/apt/lists/*
+
+# Paho MQTT (required by mqtt_status plugin carried in trunk-reporter image)
+WORKDIR /deps
+RUN git clone --depth 1 --branch v1.3.13 https://github.com/eclipse/paho.mqtt.c.git && \
+    cd paho.mqtt.c && \
+    cmake -Bbuild -DPAHO_WITH_SSL=ON -DPAHO_BUILD_SHARED=ON -DPAHO_BUILD_STATIC=OFF && \
+    cmake --build build -j$(nproc) && cmake --install build
+
+RUN git clone --depth 1 --branch v1.4.1 https://github.com/eclipse/paho.mqtt.cpp.git && \
+    cd paho.mqtt.cpp && \
+    cmake -Bbuild -DPAHO_WITH_SSL=ON -DPAHO_BUILD_SHARED=ON -DPAHO_BUILD_STATIC=OFF && \
+    cmake --build build -j$(nproc) && cmake --install build
+
+RUN ldconfig
+
+# Clone trunk-recorder pinned to the same commit the trunk-reporter plugins
+# were built against (v5.1.1 @ 31d0059)
+WORKDIR /src
+RUN git clone https://github.com/TrunkRecorder/trunk-recorder.git . && \
+    git checkout 31d0059e934ce0801b9a8df83d1a0d9edd27e824
+
+# Apply Call Alert (TSBK 0x1F) decoding patch directly
+RUN python3 - <<'EOF'
+import re
+
+# 1. parser.h — add CALL_ALERT to MessageType enum
+path = "trunk-recorder/systems/parser.h"
+src = open(path).read()
+src = src.replace("  TDULC = 17,\n  UNKNOWN = 99",
+                  "  TDULC = 17,\n  CALL_ALERT = 18,\n  UNKNOWN = 99")
+open(path, "w").write(src)
+
+# 2. p25_parser.cc — replace stub with real decode
+path = "trunk-recorder/systems/p25_parser.cc"
+src = open(path).read()
+old = '  } else if (opcode == 0x1f) {\n    BOOST_LOG_TRIVIAL(debug) << "tsbk1f: Call Alert";'
+new = '''  } else if (opcode == 0x1f) { // Call Alert
+    unsigned long src = bitset_shift_mask(tsbk, 16, 0xffffff);
+    unsigned long dst = bitset_shift_mask(tsbk, 40, 0xffffff);
+
+    message.message_type = CALL_ALERT;
+    message.source = src;
+    message.talkgroup = dst;
+
+    BOOST_LOG_TRIVIAL(info) << "tsbk1f\\tCall Alert\\tSource Unit: " << std::dec << src << "\\tTarget Unit: " << dst;'''
+assert old in src, "p25_parser.cc stub not found — check source version"
+src = src.replace(old, new)
+open(path, "w").write(src)
+
+# 3. monitor_systems.cc — add CALL_ALERT case to switch
+path = "trunk-recorder/monitor_systems.cc"
+src = open(path).read()
+old = "    case UU_ANS_REQ:\n      unit_answer_request(sys, message.source, message.talkgroup);\n      break;\n\n    case INVALID_CC_MESSAGE:"
+new = "    case UU_ANS_REQ:\n      unit_answer_request(sys, message.source, message.talkgroup);\n      break;\n\n    case CALL_ALERT:\n      break;\n\n    case INVALID_CC_MESSAGE:"
+assert old in src, "monitor_systems.cc switch not found — check source version"
+src = src.replace(old, new)
+open(path, "w").write(src)
+
+print("All patches applied successfully")
+EOF
+
+WORKDIR /src/build
+RUN cmake .. && make -j$(nproc) && make DESTDIR=/newroot install
+
+# Final image: start from trunk-reporter (has all plugins) and replace the binary
+FROM runtime_base
+
+COPY --from=builder /newroot/usr/local/bin/trunk-recorder /usr/local/bin/trunk-recorder
+
+WORKDIR /app
+ENV HOME=/tmp
+CMD trunk-recorder --config=/app/config.json
diff --git a/patches/simplestream-dangling-pointer.patch b/patches/simplestream-dangling-pointer.patch
new file mode 100644
index 00000000..15838fdf
--- /dev/null
+++ b/patches/simplestream-dangling-pointer.patch
@@ -0,0 +1,53 @@
+--- a/plugins/simplestream/simplestream.cc
++++ b/plugins/simplestream/simplestream.cc
+@@ -104,6 +104,7 @@ class Simple_Stream : public Plugin_Api {
+             json json_object;
+             std::string json_string;
+             std::vector<boost::asio::const_buffer> send_buffer;
++            uint32_t json_length = 0;
+             if (stream.sendJSON==true){
+               //create JSON metadata
+               json_object = {
+@@ -117,7 +118,7 @@ class Simple_Stream : public Plugin_Api {
+                  {"event","audio"},
+               };
+               json_string = json_object.dump();
+-              uint32_t json_length = json_string.length();  //determine length in bytes
++              json_length = json_string.length();  //determine length in bytes
+               //BOOST_LOG_TRIVIAL(debug) << "json_length is " <<json_length <<" bytes";
+               send_buffer.push_back(buffer(&json_length,4));  //prepend length of the json data
+               send_buffer.push_back(buffer(json_string));  //prepend json data
+@@ -180,6 +181,7 @@ class Simple_Stream : public Plugin_Api {
+               json json_object;
+               std::string json_string;
+               std::vector<boost::asio::const_buffer> send_buffer;
++              uint32_t json_length = 0;
+               if (stream.sendJSON==true){
+                 //create JSON metadata
+                 json_object = {
+@@ -194,7 +196,7 @@ class Simple_Stream : public Plugin_Api {
+                    {"event","call_start"},
+                 };
+                 json_string = json_object.dump();
+-                uint32_t json_length = json_string.length();  //determine length in bytes
++                json_length = json_string.length();  //determine length in bytes
+                 send_buffer.push_back(buffer(&json_length,4));  //prepend length of the json data
+                 send_buffer.push_back(buffer(json_string));  //prepend json data
+               }
+@@ -231,6 +233,7 @@ class Simple_Stream : public Plugin_Api {
+               json json_object;
+               std::string json_string;
+               std::vector<boost::asio::const_buffer> send_buffer;
++              uint32_t json_length = 0;
+               if (stream.sendJSON==true){
+                 //create JSON metadata
+                 json_object = {
+@@ -241,7 +244,7 @@ class Simple_Stream : public Plugin_Api {
+                    {"event","call_end"},
+                 };
+                 json_string = json_object.dump();
+-                uint32_t json_length = json_string.length();  //determine length in bytes
++                json_length = json_string.length();  //determine length in bytes
+                 send_buffer.push_back(buffer(&json_length,4));  //prepend length of the json data
+                 send_buffer.push_back(buffer(json_string));  //prepend json data
+               }
diff --git a/trunk-recorder/monitor_systems.cc b/trunk-recorder/monitor_systems.cc
index dcf48d0e..f1f9c4c6 100644
--- a/trunk-recorder/monitor_systems.cc
+++ b/trunk-recorder/monitor_systems.cc
@@ -674,6 +674,9 @@ void handle_message(std::vector<TrunkMessage> messages, System *sys, Config &con
       unit_answer_request(sys, message.source, message.talkgroup);
       break;
 
+    case CALL_ALERT:
+      break;
+
     case INVALID_CC_MESSAGE:
     {
       //Do not count messages that aren't valid TSBK or MBTs.
diff --git a/trunk-recorder/systems/p25_parser.cc b/trunk-recorder/systems/p25_parser.cc
index 37fb78d3..75785481 100644
--- a/trunk-recorder/systems/p25_parser.cc
+++ b/trunk-recorder/systems/p25_parser.cc
@@ -702,8 +702,15 @@ std::vector<TrunkMessage> P25Parser::decode_tsbk(boost::dynamic_bitset<> &tsbk,
     BOOST_LOG_TRIVIAL(debug) << "tsbk1c: Messag Update";
   } else if (opcode == 0x1d) {
     BOOST_LOG_TRIVIAL(debug) << "tsbk1d: Radio Unit Monitor Command";
-  } else if (opcode == 0x1f) {
-    BOOST_LOG_TRIVIAL(debug) << "tsbk1f: Call Alert";
+  } else if (opcode == 0x1f) { // Call Alert
+    unsigned long src = bitset_shift_mask(tsbk, 16, 0xffffff);
+    unsigned long dst = bitset_shift_mask(tsbk, 40, 0xffffff);
+
+    message.message_type = CALL_ALERT;
+    message.source = src;
+    message.talkgroup = dst;
+
+    BOOST_LOG_TRIVIAL(info) << "tsbk1f\tCall Alert\tSource Unit: " << std::dec << src << "\tTarget Unit: " << dst;
   } else if (opcode == 0x20) { // Acknowledge response
     // unsigned long mfrid  = bitset_shift_mask(tsbk,80,0xff);
     unsigned long ga = bitset_shift_mask(tsbk, 40, 0xffff);
diff --git a/trunk-recorder/systems/parser.h b/trunk-recorder/systems/parser.h
index f435d2cb..e338497e 100644
--- a/trunk-recorder/systems/parser.h
+++ b/trunk-recorder/systems/parser.h
@@ -22,6 +22,7 @@ enum MessageType {
   UU_V_UPDATE = 15,
   INVALID_CC_MESSAGE = 16,
   TDULC = 17,
+  CALL_ALERT = 18,
   UNKNOWN = 99
 };