diff --git a/src/Makefile.am b/src/Makefile.am
index e2f14968..ecacd801 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -183,6 +183,8 @@ utun_CORE_SOURCES = \
 	dm/dm_mailbox_media.c \
 	dm/dm_mailbox_media.h \
 	call/call.c \
+	call/call_video_rate.c \
+	call/call_video_rate.h \
 	call/call_headless.c \
 	radio/radio.c \
 	radio/radio_headless.c \
@@ -334,6 +336,8 @@ libutun_a_SOURCES = \
 	dm/dm_mailbox_media.c \
 	dm/dm_mailbox_media.h \
 	call/call.c \
+	call/call_video_rate.c \
+	call/call_video_rate.h \
 	call/call_headless.c \
 	radio/radio.c \
 	radio/radio_headless.c \
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 5e96ee75..40906eee 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -10,6 +10,7 @@ EXTRA_DIST = fixtures/reality_openssl_hello.hex data/silero_speech.pcm data/sile
 # Быстрые проверки (до 100мс).
 check_PROGRAMS = \
     test_route_tx_stats \
+    test_call_video_rate \
     test_memory_pool_and_config \
     test_serialize \
     test_reed_solomon \
@@ -676,6 +677,9 @@ test_dm_worker_LDADD = $(LIBUTUN) $(CRYPTO_LIBS) $(COMMON_LIBS)
 test_call_SOURCES = test_call.c
 test_route_tx_stats_SOURCES = test_route_tx_stats.c
 test_route_tx_stats_LDADD = $(LIBUTUN) $(COMMON_LIBS)
+
+test_call_video_rate_SOURCES = test_call_video_rate.c
+test_call_video_rate_LDADD = $(LIBUTUN) $(COMMON_LIBS)
 test_call_CFLAGS = -I$(top_srcdir)/src -I$(top_srcdir)/src/chat -I$(top_srcdir)/src/dm -I$(top_srcdir)/src/call -I$(top_srcdir)/src/routing_layer -I$(top_srcdir)/src/transport_layer -I$(top_srcdir)/lib
 test_call_LDADD = $(LIBUTUN) $(CRYPTO_LIBS) $(COMMON_LIBS)
 
diff --git a/tests/test_call_video_rate.c b/tests/test_call_video_rate.c
new file mode 100644
index 00000000..96c0f295
--- /dev/null
+++ b/tests/test_call_video_rate.c
@@ -0,0 +1,102 @@
+/* Замкнутая модель источника/узкого канала/ACK с управляемым временем. */
+#include <stdlib.h>
+#include <string.h>
+#include "../src/call/call_video_rate.h"
+#include "../lib/debug_config.h"
+
+#define CHECK(x) do { if (!(x)) { DEBUG_ERROR(DEBUG_CATEGORY_CALL, "rate test line=%d: %s", __LINE__, #x); exit(1); } } while (0)
+
+static struct call_video_rate_sample sample(uint64_t now) {
+    struct call_video_rate_sample s = {.now_us = now, .window_end_us = now / 50000 * 50000,
+        .applied_bps = 2000000, .minimum_bps = 100000, .maximum_bps = 4000000,
+        .baseline_rtt_us = 100000, .rtt_us = 100000, .frame_interval_us = 33333,
+        .debt_limit_bytes = 500000, .valid = 1, .ready = 1};
+    return s;
+}
+
+static void test_gates(void) {
+    struct call_video_rate rate;
+    struct call_video_rate_result out;
+    struct call_video_rate_sample s = sample(1000000);
+    call_video_rate_init(&rate, s.now_us);
+    CHECK(call_video_rate_step(&rate, &s, &out) == 0 && out.target_bps == s.applied_bps);
+    s.now_us = s.window_end_us = 2000000;
+    s.maximum_bps = 1000000; s.command_pending = 1;
+    CHECK(call_video_rate_step(&rate, &s, &out) == 0 && out.target_bps == s.applied_bps);
+    s.command_pending = 0;
+    CHECK(call_video_rate_step(&rate, &s, &out) == 0 && out.target_bps == 1000000 && out.reason == CALL_VIDEO_RATE_LIMIT);
+    s.maximum_bps = 4000000; s.debt_bytes = s.debt_limit_bytes;
+    s.no_route = 1;
+    CHECK(call_video_rate_step(&rate, &s, &out) == 0 && !out.admit && out.reason == CALL_VIDEO_RATE_BLOCKED);
+    s.no_route = 0; s.valid = 0;
+    CHECK(call_video_rate_step(&rate, &s, &out) == 0 && !out.admit && out.target_bps == s.applied_bps);
+    s.valid = 1; s.probing = 1; s.now_us = s.window_end_us = 3000000;
+    CHECK(call_video_rate_step(&rate, &s, &out) == 0 && out.target_bps == s.applied_bps);
+    s.probing = 0; s.locally_held = 1;
+    CHECK(call_video_rate_step(&rate, &s, &out) == 0 && out.target_bps == s.applied_bps);
+    struct call_video_rate saved = rate;
+    s.now_us--;
+    CHECK(call_video_rate_step(&rate, &s, &out) < 0 && !memcmp(&saved, &rate, sizeof(rate)));
+    DEBUG_INFO(DEBUG_CATEGORY_CALL, "PASS rate: cap, pending, no route, queue bound, warmup, probe and local hold");
+}
+
+/* Нормальный inflight на длинном RTT не должен выглядеть как перегрузка. */
+static void test_long_rtt(void) {
+    struct call_video_rate rate;
+    struct call_video_rate_result out;
+    struct call_video_rate_sample s = sample(0);
+    s.applied_bps = s.maximum_bps = 1600000;
+    s.rtt_us = s.baseline_rtt_us = 600000;
+    s.produced_bytes = s.delivered_bytes = 100000;
+    s.debt_bytes = 120000;
+    call_video_rate_init(&rate, 0);
+    for (unsigned i = 0; i < 200; i++) {
+        s.now_us = s.window_end_us = (uint64_t)i * 50000;
+        CHECK(call_video_rate_step(&rate, &s, &out) == 0);
+        CHECK(out.target_bps == s.applied_bps && out.admit && !out.excess_bytes);
+    }
+    DEBUG_INFO(DEBUG_CATEGORY_CALL, "PASS rate: 600ms RTT inflight is not congestion");
+}
+
+/* Объём каждого шага сохраняется до ACK; delivered задержан на два шага (100мс RTT). */
+static void test_channel(int static_scene) {
+    struct call_video_rate rate;
+    struct call_video_rate_sample s = sample(0);
+    struct call_video_rate_result out = {.admit = 1};
+    uint64_t produced[10] = {0}, delivered[10] = {0}, flight[2] = {0};
+    uint64_t queue = 0, debt = 0, max_debt = 0;
+    uint32_t before_increase = 0;
+    unsigned cuts = 0, probes = 0;
+    call_video_rate_init(&rate, 0);
+    for (unsigned i = 0; i < 2400; i++) {
+        uint64_t generated = out.admit ? s.applied_bps / (static_scene ? 16000 : 160) : 0;
+        queue += generated; debt += generated;
+        uint64_t acked = flight[i % 2]; debt -= acked;
+        uint64_t capacity = (i < 1200 ? 1500000 : 3000000) / 160;
+        uint64_t sent = queue < capacity ? queue : capacity;
+        queue -= sent; flight[i % 2] = sent;
+        produced[i % 10] = generated; delivered[i % 10] = acked;
+        s.produced_bytes = s.delivered_bytes = 0;
+        for (unsigned j = 0; j < 10; j++) { s.produced_bytes += produced[j]; s.delivered_bytes += delivered[j]; }
+        s.now_us = s.window_end_us = (uint64_t)(i + 1) * 50000;
+        s.valid = i >= 9; s.debt_bytes = debt;
+        CHECK(call_video_rate_step(&rate, &s, &out) == 0);
+        if (out.reason == CALL_VIDEO_RATE_DRAIN) cuts++;
+        if (out.reason == CALL_VIDEO_RATE_PROBE) probes++;
+        s.applied_bps = out.target_bps;
+        CHECK(s.applied_bps >= s.minimum_bps && s.applied_bps <= s.maximum_bps);
+        if (debt > max_debt) max_debt = debt;
+        if (i == 1199) before_increase = s.applied_bps;
+    }
+    DEBUG_INFO(DEBUG_CATEGORY_CALL, "rate model static=%d max_debt=%llu cuts=%u probes=%u before=%u final=%u",
+               static_scene, (unsigned long long)max_debt, cuts, probes, before_increase, s.applied_bps);
+    CHECK(max_debt < 250000 && probes > 10);
+    if (static_scene) CHECK(cuts == 0 && s.applied_bps == s.maximum_bps);
+    else CHECK(cuts > 0 && before_increase < 1800000 && s.applied_bps > 2000000 && s.applied_bps < 3400000);
+}
+
+int main(void) {
+    debug_config_init(); debug_set_level(DEBUG_LEVEL_INFO);
+    test_gates(); test_long_rtt(); test_channel(0); test_channel(1);
+    return 0;
+}