diff --git a/src/transport_layer/etcp.h b/src/transport_layer/etcp.h
index a4e9dd2a..032bda23 100644
--- a/src/transport_layer/etcp.h
+++ b/src/transport_layer/etcp.h
@@ -163,6 +163,7 @@ struct ETCP_CONN {
     // IDs and state
     uint32_t next_tx_id;           // ID для добавления в очередь отправки (с этим id будет добавлен следующий пакет)
     uint64_t next_attempt_id;      // Не переиспользуется при reset/пересоздании линков; исчерпание закрывает соединение
+    uint32_t active_attempts;      // Все физические записи, включая резерв send; максимум 2*MAX_INFLIGHT_SIZE
     uint32_t last_rx_id;           // Last received ID
     uint32_t last_delivered_id;    // Last delivered to output_queue
 
diff --git a/src/transport_layer/etcp_tx.c b/src/transport_layer/etcp_tx.c
index ff6f5438..975f7291 100644
--- a/src/transport_layer/etcp_tx.c
+++ b/src/transport_layer/etcp_tx.c
@@ -51,13 +51,14 @@ static void retransmit_arm(struct ETCP_LINK* link) {
 static void attempt_retire(struct ETCP_LINK* link, struct ETCP_TX_ATTEMPT* attempt, int loss, int retry) {
     struct ETCP_CONN* conn = link->etcp;
     struct INFLIGHT_PACKET* packet = logical_find(conn, attempt->seq);
-    if (link->inflight_bytes < attempt->ll.len || !link->inflight_packets || (packet && !packet->active_attempts)) {
+    if (!conn->active_attempts || link->inflight_bytes < attempt->ll.len || !link->inflight_packets ||
+        (packet && !packet->active_attempts)) {
         DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "[%s] attempt accounting mismatch link=%u id=%llu seq=%u flight=%u/%u len=%u logical=%u",
             conn->log_name, link->local_link_id, (unsigned long long)attempt->attempt_id, attempt->seq,
             link->inflight_bytes, link->inflight_packets, attempt->ll.len, packet ? packet->active_attempts : 0);
         abort();
     }
-    link->inflight_bytes -= attempt->ll.len; link->inflight_packets--;
+    link->inflight_bytes -= attempt->ll.len; link->inflight_packets--; conn->active_attempts--;
     if (packet) packet->active_attempts--;
     if (loss && link->bbr) {
         uint64_t lost = (uint64_t)link->bbr_loss_since_ack + attempt->ll.len;
@@ -101,7 +102,11 @@ static void retransmit_cb(void* arg) {
 int etcp_tx_link_init(struct ETCP_LINK* link) {
     link->attempts = queue_new(link->etcp->instance->ua, 128, 0, 8, "ETCP attempts");
     link->ack_q = queue_new(link->etcp->instance->ua, 128, 0, 8, "ETCP path ACK");
-    if (link->attempts && link->ack_q) return 0;
+    if (link->attempts && link->ack_q) {
+        queue_set_size_limit(link->attempts, MAX_INFLIGHT_SIZE);
+        queue_set_size_limit(link->ack_q, MAX_INFLIGHT_SIZE);
+        return 0;
+    }
     DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "[%s] cannot initialize link attempt/ACK queues", link->etcp->log_name);
     if (link->attempts) queue_free(link->attempts);
     if (link->ack_q) queue_free(link->ack_q);
@@ -142,6 +147,11 @@ void etcp_tx_link_destroy(struct ETCP_LINK* link) {
 
 struct ETCP_TX_ATTEMPT* etcp_tx_prepare(struct ETCP_LINK* link, struct INFLIGHT_PACKET* packet) {
     struct ETCP_CONN* conn = link->etcp;
+    if (conn->active_attempts >= 2 * MAX_INFLIGHT_SIZE || link->attempts->count >= MAX_INFLIGHT_SIZE) {
+        DEBUG_WARN(DEBUG_CATEGORY_ETCP, "[%s] transmission attempt budget exhausted: total=%u path=%u count=%d",
+            conn->log_name, conn->active_attempts, link->local_link_id, link->attempts->count);
+        return NULL;
+    }
     if (!conn->next_attempt_id || conn->next_attempt_id == UINT64_MAX) {
         DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "[%s] transmission attempt ID exhausted", conn->log_name);
         conn->callbacks_running++; etcp_connection_close(conn); conn->callbacks_running--; return NULL;
@@ -152,7 +162,7 @@ struct ETCP_TX_ATTEMPT* etcp_tx_prepare(struct ETCP_LINK* link, struct INFLIGHT_
     if (queue_data_put_with_index(link->attempts, &attempt->ll) < 0) {
         DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "[%s] cannot index transmission attempt", conn->log_name); return NULL;
     }
-    link->inflight_bytes += packet->ll.len; link->inflight_packets++; packet->active_attempts++;
+    link->inflight_bytes += packet->ll.len; link->inflight_packets++; packet->active_attempts++; conn->active_attempts++;
     return attempt;
 }