diff --git a/src/tcp_proxy.c b/src/tcp_proxy.c
index 91c0aecd..32fe4437 100644
--- a/src/tcp_proxy.c
+++ b/src/tcp_proxy.c
@@ -53,6 +53,7 @@ static void etcp_transport_close(struct tcp_proxy_transport* t);
 static void etcp_transport_destroy(struct tcp_proxy_transport* t);
 static void sock_transport_connect(struct sock_transport* st);
 static void proxy_try_close(struct proxy_conn *pc);
+static void proxy_uip_retry_cb(void* arg);
 static struct sock_transport* sock_transport_create(struct proxy_conn* pc, struct UASYNC* ua);
 static struct etcp_transport* etcp_transport_create(struct proxy_conn* pc, struct UTUN_INSTANCE* inst, uint64_t remote_node_id);
 
@@ -200,6 +201,14 @@ static void transport_to_uip_cb(struct ll_queue* q, void* arg) {
 // ====================================================================
 static void proxy_feed_from_transport(struct proxy_conn *pc) {
     if (!pc->transport_to_uip || !pc->pcb) return;
+    if (pc->closing_tun || pc->closing_sent) {
+        struct ll_entry *e;
+        while ((e = queue_data_get(pc->transport_to_uip))) {
+            queue_dgram_free(e); queue_entry_free(e);
+            queue_resume_callback(pc->transport_to_uip);
+        }
+        return;
+    }
     int sent_any = 0;
     int entries_fed = 0;
     while (1) {
@@ -277,9 +286,6 @@ static err_t proxy_recv_cb(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t
         DEBUG_INFO(DEBUG_CATEGORY_SOCKET, "PROXY FIN stream=%016llx tun=1 active=%d", (unsigned long long)(pc->remote_stream_id ? pc->remote_stream_id : 0), pc->active);
         { uint16_t wnd_gap = TCP_WND_MAX(pcb) - pcb->rcv_wnd;
           if (wnd_gap > 0) tcp_recved(pcb, wnd_gap); }
-        if (pc->transport_to_uip) {
-            struct ll_entry* e; while ((e = queue_data_get(pc->transport_to_uip))) { queue_dgram_free(e); queue_entry_free(e); }
-        }
         pc->closing_tun = 1;
         return LERR_OK;
     }
@@ -297,9 +303,11 @@ static err_t proxy_recv_cb(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t
             pbuf_copy_partial(p, data, len, 0);
             int ret = pc->transport->ops->send(pc->transport, data, len);
             if (ret < 0) {
-                DEBUG_ERROR(DEBUG_CATEGORY_SOCKET, "PROXY send failed stream=%016llx ret=%d len=%u", (unsigned long long)pc->remote_stream_id, ret, len);
-                struct ll_entry *e = entry_from_data(pc->proxy->entry_pool, data, len);
+                DEBUG_INFO(DEBUG_CATEGORY_SOCKET, "PROXY send queued stream=%016llx ret=%d len=%u", (unsigned long long)pc->remote_stream_id, ret, len);
+                struct ll_entry *e = entry_from_data(pc->proxy->entry_pool, p->payload, p->tot_len);
                 if (e) queue_data_put(pc->uip_to_transport, e);
+                if (!pc->uip_retry_timer)
+                    pc->uip_retry_timer = uasync_set_timeout(pc->proxy->ua, 50, pc, proxy_uip_retry_cb, "uip_retry");
             }
             u_free(data);
         }
@@ -317,6 +325,21 @@ static err_t proxy_sent_cb(void *arg, struct tcp_pcb *pcb, uint16_t len) {
     return LERR_OK;
 }
 
+static void proxy_uip_retry_cb(void* arg) {
+    struct proxy_conn* pc = (struct proxy_conn*)arg;
+    pc->uip_retry_timer = NULL;
+    struct ll_entry* e = queue_data_get(pc->uip_to_transport);
+    if (!e) { queue_resume_callback(pc->uip_to_transport); return; }
+    int ret = pc->transport ? pc->transport->ops->send(pc->transport, e->dgram, e->len) : -1;
+    if (ret < 0) {
+        queue_data_put_first(pc->uip_to_transport, e);
+        pc->uip_retry_timer = uasync_set_timeout(pc->proxy->ua, 50, pc, proxy_uip_retry_cb, "uip_retry");
+    } else {
+        queue_dgram_free(e); queue_entry_free(e);
+    }
+    queue_resume_callback(pc->uip_to_transport);
+}
+
 static void proxy_err_cb(void *arg, err_t err) {
     struct proxy_conn *pc = (struct proxy_conn *)arg;
     if (!pc) { DEBUG_ERROR(DEBUG_CATEGORY_SOCKET, "PROXY proxy_err_cb: pc=NULL err=%d", err); return; }
@@ -358,6 +381,7 @@ static err_t proxy_poll_cb(void *arg, struct tcp_pcb *pcb) {
         struct proxy_conn **prev = &proxy->conns;
         while (*prev) { if (*prev == pc) { *prev = pc->next; proxy->conn_count--; break; } prev = &(*prev)->next; }
         if (pc->transport) { pc->transport->ops->destroy(pc->transport); pc->transport = NULL; }
+        if (pc->uip_retry_timer) { uasync_cancel_timeout(pc->proxy->ua, pc->uip_retry_timer); pc->uip_retry_timer = NULL; }
         if (pc->eim_mapping) { pc->eim_mapping->delete_at_tb = get_time_tb() + proxy->eim_timeout_tb; pc->eim_mapping = NULL; }
         if (pc->uip_to_transport) { struct ll_entry *e2; while ((e2 = queue_data_get(pc->uip_to_transport))) { queue_dgram_free(e2); queue_entry_free(e2); } queue_free(pc->uip_to_transport); }
         if (pc->transport_to_uip) { struct ll_entry *e2; while ((e2 = queue_data_get(pc->transport_to_uip))) { queue_dgram_free(e2); queue_entry_free(e2); } queue_free(pc->transport_to_uip); }
@@ -613,7 +637,7 @@ static void sock_transport_error_callback(socket_t sock, void* arg) {
 // ====================================================================
 static int etcp_transport_send(struct tcp_proxy_transport* t, const uint8_t* data, size_t len) {
     struct etcp_transport* et = (struct etcp_transport*)t;
-    if (!et->connected) { DEBUG_INFO(DEBUG_CATEGORY_SOCKET, "PROXY send not connected stream=%016llx len=%zu", (unsigned long long)et->stream_id, len); return -1; }
+    if (!et->connected) return -1;
     struct ll_entry* e = queue_entry_new(0);
     if (!e) { DEBUG_ERROR(DEBUG_CATEGORY_SOCKET, "PROXY send alloc entry fail stream=%016llx", (unsigned long long)et->stream_id); return -1; }
     e->dgram = u_malloc(TCP_PROXY_HDR_SIZE + len);
@@ -878,6 +902,7 @@ void tcp_proxy_destroy(struct tcp_proxy* p) {
     struct proxy_conn* pc = p->conns;
     while (pc) { struct proxy_conn* next = pc->next;
         if (pc->transport) pc->transport->ops->destroy(pc->transport);
+        if (pc->uip_retry_timer) { uasync_cancel_timeout(p->ua, pc->uip_retry_timer); pc->uip_retry_timer = NULL; }
         if (pc->uip_to_transport) { struct ll_entry* e; while ((e = queue_data_get(pc->uip_to_transport))) { queue_dgram_free(e); queue_entry_free(e); } queue_free(pc->uip_to_transport); }
         if (pc->transport_to_uip) { struct ll_entry* e; while ((e = queue_data_get(pc->transport_to_uip))) { queue_dgram_free(e); queue_entry_free(e); } queue_free(pc->transport_to_uip); }
         u_free(pc); pc = next; }
diff --git a/src/tcp_proxy.h b/src/tcp_proxy.h
index 4aa10eba..558be2d1 100644
--- a/src/tcp_proxy.h
+++ b/src/tcp_proxy.h
@@ -63,6 +63,7 @@ struct proxy_conn {
     int                active;             // 1 = outgoing connection
     struct tcp_proxy_mapping* eim_mapping;
     uint64_t           remote_stream_id;   // stream ID for remote proxy (0=local)
+    void*              uip_retry_timer;    // timer for backpressure retry
 };
 
 // Main TCP proxy module