diff --git a/src/etcp_connections.c b/src/etcp_connections.c
index 53e1afa..81b1d56 100644
--- a/src/etcp_connections.c
+++ b/src/etcp_connections.c
@@ -29,6 +29,17 @@ static void etcp_link_init_timer_cbk(void* arg);
 static void etcp_link_send_keepalive(struct ETCP_LINK* link);
 static void keepalive_timer_cb(void* arg);
 
+void etcp_link_update_inflight_lim(struct ETCP_LINK* link, uint32_t new_lim) {
+    if (!link) return;
+    uint32_t old = link->inflight_lim_bytes;
+    link->inflight_lim_bytes = new_lim;
+    if (old != new_lim && link->inflight_bytes < new_lim && link->send_blocked_inflight) {
+        link->send_blocked_inflight = 0;
+        loadbalancer_link_ready(link);
+        DEBUG_DEBUG(DEBUG_CATEGORY_ETCP, "etcp_link_update_inflight_lim: unblocked link (lim %u->%u)", old, new_lim);
+    }
+}
+
 #define INIT_TIMEOUT_INITIAL 500
 #define INIT_TIMEOUT_MAX 50000
 
@@ -552,6 +563,7 @@ struct ETCP_LINK* etcp_link_new(struct ETCP_CONN* etcp, struct ETCP_SOCKET* conn
     if (link->keepalive_interval < 10) link->keepalive_interval = 10;
     link->keepalive_sent_count = 0;
     link->keepalive_recv_count = 0;
+    link->inflight_lim_bytes = 30000;
 
     // Выделяем свободный local_link_id
     int free_id = etcp_find_free_local_link_id(etcp);
diff --git a/src/etcp_connections.h b/src/etcp_connections.h
index ded8939..d39ea09 100644
--- a/src/etcp_connections.h
+++ b/src/etcp_connections.h
@@ -92,6 +92,14 @@ struct ETCP_LINK {
 
     uint32_t inflight_bytes;
     uint32_t inflight_packets;
+    uint32_t inflight_lim_bytes;
+
+    /* Биты блокировки отправки по причине (для корректного resume) */
+    unsigned send_blocked_input_queue : 1;
+    unsigned send_blocked_sack_full   : 1;
+    unsigned send_blocked_bandwidth   : 1;
+    unsigned send_blocked_inflight    : 1;
+    unsigned send_blocked_other       : 4;
 
     size_t encrypt_errors;
     size_t decrypt_errors;
@@ -147,6 +155,9 @@ int etcp_encrypt_send(struct ETCP_DGRAM* dgram);// зашифровывает и
 // find link by address
 struct ETCP_LINK* etcp_link_find_by_addr(struct ETCP_SOCKET* e_sock, struct sockaddr_storage* addr);
 
+// обновляет лимит inflight_bytes для линка и корректно снимает блокировку если нужно
+void etcp_link_update_inflight_lim(struct ETCP_LINK* link, uint32_t new_lim);
+
 // find free local_link_id for connection
 // scans all links in connection, marks used ids in bit array
 // returns first free id (0-255) or -1 if all occupied
diff --git a/src/etcp_loadbalancer.c b/src/etcp_loadbalancer.c
index 6a298f5..1588e4d 100644
--- a/src/etcp_loadbalancer.c
+++ b/src/etcp_loadbalancer.c
@@ -45,7 +45,11 @@ struct ETCP_LINK* etcp_loadbalancer_select_link(struct ETCP_CONN* etcp) {
 //                    link_index, link, link->initialized, link->shaper_timer==NULL?1:0,
 //                    (unsigned long long)link->shaper_load_time_tb, (unsigned long long)link->shaper_sub_nanotime);
         
-        if (!link->initialized || link->shaper_timer || link->link_status != 1) {// если установлен таймер - значит надо ждать. не рассматриваем этот линк
+        if (!link->initialized || link->link_status != 1) {
+            link = link->next;
+            continue;
+        }
+        if (loadbalancer_link_can_send(link) == 0) {
             link = link->next;
             continue;
         }
@@ -144,22 +148,38 @@ void etcp_loadbalancer_send(struct ETCP_DGRAM* dgram) {
     memory_pool_free(etcp->instance->pkt_pool, dgram);
 }
 
-// New: Notify when link is ready (called from timer or external)
+int loadbalancer_link_can_send(struct ETCP_LINK* link) {
+    if (!link) return 0;
+    int can = 1;
+    if (link->inflight_bytes >= link->inflight_lim_bytes) {
+        link->send_blocked_inflight = 1;
+        can = 0;
+    } else {
+        link->send_blocked_inflight = 0;
+    }
+    if (link->shaper_timer) {
+        link->send_blocked_bandwidth = 1;
+        can = 0;
+    } else {
+        link->send_blocked_bandwidth = 0;
+    }
+    return can;
+}
+
 void loadbalancer_link_ready(struct ETCP_LINK* link) {
     if (!link || !link->etcp) {
         DEBUG_WARN(DEBUG_CATEGORY_ETCP, "loadbalancer_link_ready: invalid link (%p)", link);
         return;
     }
-
+    if (loadbalancer_link_can_send(link) == 0) {
+        DEBUG_DEBUG(DEBUG_CATEGORY_ETCP, "loadbalancer_link_ready: link still blocked");
+        return;
+    }
     DEBUG_INFO(DEBUG_CATEGORY_ETCP, "loadbalancer_link_ready: link=%p now ready, notifying ETCP_CONN", link);
-
-    // Call ETCP_CONN resume (assumes link_ready_for_send_fn in ETCP_CONN; add to etcp.h: void (*link_ready_for_send_fn)(struct ETCP_CONN*);)
     if (link->etcp->link_ready_for_send_fn) {
         link->etcp->link_ready_for_send_fn(link->etcp);
     } else {
-        // Fallback: request next packet (implement etcp_request_pkt in etcp.c if needed)
-        // etcp_request_pkt(link->etcp);
-        DEBUG_WARN(DEBUG_CATEGORY_ETCP, "loadbalancer_link_ready: no link_ready_for_send_fn set, skipping notify");
+        DEBUG_WARN(DEBUG_CATEGORY_ETCP, "loadbalancer_link_ready: no link_ready_for_send_fn set");
     }
 }
 
diff --git a/src/etcp_loadbalancer.h b/src/etcp_loadbalancer.h
index 594484c..47c578e 100644
--- a/src/etcp_loadbalancer.h
+++ b/src/etcp_loadbalancer.h
@@ -23,9 +23,12 @@ struct ETCP_LINK* etcp_loadbalancer_select_link(struct ETCP_CONN* etcp);
 //void etcp_loadbalancer_update_after_send(struct ETCP_LINK* link, size_t pkt_size); - это надо заменить на:
 void etcp_loadbalancer_send(struct ETCP_DGRAM* dgram);
 
-// сообщаем в loadbalancer о готовности линка
+// сообщаем в loadbalancer о готовности линка (вызывается из таймера, ACK, изменения лимита)
 void loadbalancer_link_ready(struct ETCP_LINK* link);
 
+// проверяет все условия блокировки отправки (включая inflight_bytes)
+int loadbalancer_link_can_send(struct ETCP_LINK* link);
+
 // Получить состояние связи ETCP: 1 - есть живой линк, 0 - все недоступны
 int etcp_loadbalancer_get_link_status(struct ETCP_CONN* etcp);