diff --git a/tunnels/client/http2/http2_client.c b/tunnels/client/http2/http2_client.c
index 3abe4632..6fd0941d 100644
--- a/tunnels/client/http2/http2_client.c
+++ b/tunnels/client/http2/http2_client.c
@@ -188,20 +188,25 @@ static int onHeaderCallback(nghttp2_session *session, const nghttp2_frame *frame
     //         // req->headers["Host"] = value;
     //     }
     // }
-    http2_client_child_con_state_t *stream = nghttp2_session_get_stream_user_data(session, frame->hd.stream_id);
-    if (stream)
+
+    if (strcmp((const char *) name, "grpc-ack") == 0)
     {
-        if (strcmp((const char *) name, "grpc-ack") == 0)
+        http2_client_child_con_state_t *stream = nghttp2_session_get_stream_user_data(session, frame->hd.stream_id);
+        if (stream)
         {
             const int consumed = atoi((const char *) value);
-            if (stream->bytes_sent_nack > kMaxSendBeforeAck)
+            if (stream->bytes_sent_nack >= kMaxSendBeforeAck)
             {
                 stream->bytes_sent_nack -= consumed;
-                if (stream->bytes_sent_nack < kMaxSendBeforeAck / 2)
+                if (stream->bytes_sent_nack < kMaxSendBeforeAck)
                 {
                     resumeLineDownSide(stream->line);
                 }
             }
+            else
+            {
+                stream->bytes_sent_nack -= consumed;
+            }
         }
     }
 
@@ -253,14 +258,14 @@ static int onDataChunkRecvCallback(nghttp2_session *session, uint8_t flags, int3
                 stream_data->payload      = gdata_buf;
 
                 stream->bytes_received_nack += bufLen(gdata_buf);
-                if (stream->bytes_sent_nack >= kMaxRecvBeforeAck)
+                if (stream->bytes_received_nack >= kMaxRecvBeforeAck)
                 {
                     nghttp2_nv nvs[1];
                     char       stri[32];
-                    sprintf(stri, "%d", (int) stream->bytes_sent_nack);
+                    sprintf(stri, "%d", (int) stream->bytes_received_nack);
                     nvs[0] = makeNV("grpc-ack", stri);
                     nghttp2_submit_headers(con->session, NGHTTP2_FLAG_END_HEADERS, stream_id, NULL, &nvs[0], 1, NULL);
-                    stream->bytes_sent_nack = 0;
+                    stream->bytes_received_nack = 0;
                 }
 
                 stream->tunnel->dw->downStream(stream->tunnel->dw, stream_data);
@@ -282,14 +287,14 @@ static int onDataChunkRecvCallback(nghttp2_session *session, uint8_t flags, int3
         stream_data->payload   = buf;
 
         stream->bytes_received_nack += bufLen(buf);
-        if (stream->bytes_sent_nack >= kMaxRecvBeforeAck)
+        if (stream->bytes_received_nack >= kMaxRecvBeforeAck)
         {
             nghttp2_nv nvs[1];
             char       stri[32];
-            sprintf(stri, "%d", (int) stream->bytes_sent_nack);
+            sprintf(stri, "%d", (int) stream->bytes_received_nack);
             nvs[0] = makeNV("grpc-ack", stri);
             nghttp2_submit_headers(con->session, NGHTTP2_FLAG_END_HEADERS, stream_id, NULL, &nvs[0], 1, NULL);
-            stream->bytes_sent_nack = 0;
+            stream->bytes_received_nack = 0;
         }
 
         stream->tunnel->dw->downStream(stream->tunnel->dw, stream_data);
diff --git a/tunnels/server/http2/helpers.h b/tunnels/server/http2/helpers.h
index 3cb61d7b..6ff04cce 100644
--- a/tunnels/server/http2/helpers.h
+++ b/tunnels/server/http2/helpers.h
@@ -58,22 +58,22 @@ static void onH2LinePaused(void *arg)
 {
     http2_server_con_state_t *con = (http2_server_con_state_t *) arg;
 
-    ++(con->pause_counter);
-    if (con->pause_counter > 4)
-    {
+    // ++(con->pause_counter);
+    // if (con->pause_counter > 4)
+    // {
         http2_server_child_con_state_t *stream_i;
         for (stream_i = con->root.next; stream_i;)
         {
             pauseLineUpSide(stream_i->line);
             stream_i = stream_i->next;
         }
-    }
+    // }
 }
 
 static void onH2LineResumed(void *arg)
 {
     http2_server_con_state_t *con = (http2_server_con_state_t *) arg;
-    con->pause_counter            = con->pause_counter > 0 ? (con->pause_counter - 1) : con->pause_counter;
+    // con->pause_counter            = con->pause_counter > 0 ? (con->pause_counter - 1) : con->pause_counter;
     http2_server_child_con_state_t *stream_i;
     for (stream_i = con->root.next; stream_i;)
     {
diff --git a/tunnels/server/http2/http2_server.c b/tunnels/server/http2/http2_server.c
index 0f0011f7..8c188ac3 100644
--- a/tunnels/server/http2/http2_server.c
+++ b/tunnels/server/http2/http2_server.c
@@ -54,6 +54,26 @@ static int onHeaderCallback(nghttp2_session *session, const nghttp2_frame *frame
         {
             con->content_type = httpContentTypeEnum(value);
         }
+        else if (strcmp(name, "grpc-ack") == 0)
+        {
+            http2_server_child_con_state_t *stream = nghttp2_session_get_stream_user_data(session, frame->hd.stream_id);
+            if (stream)
+            {
+                const int consumed = atoi(value);
+                if (stream->bytes_sent_nack >= kMaxSendBeforeAck)
+                {
+                    stream->bytes_sent_nack -= consumed;
+                    if (stream->bytes_sent_nack < kMaxSendBeforeAck)
+                    {
+                        resumeLineUpSide(stream->line);
+                    }
+                }
+                else
+                {
+                    stream->bytes_sent_nack -= consumed;
+                }
+            }
+        }
     }
 
     return 0;
@@ -109,6 +129,17 @@ static int onDataChunkRecvCallback(nghttp2_session *session, uint8_t flags, int3
                     stream->first_sent = true;
                     stream_data->first = true;
                 }
+                stream->bytes_received_nack += bufLen(buf);
+                if (stream->bytes_received_nack >= kMaxRecvBeforeAck)
+                {
+                    nghttp2_nv nvs[1];
+                    char       stri[32];
+                    sprintf(stri, "%d", (int) stream->bytes_received_nack);
+                    nvs[0] = makeNV("grpc-ack", stri);
+                    nghttp2_submit_headers(con->session, NGHTTP2_FLAG_END_HEADERS, stream_id, NULL, &nvs[0], 1, NULL);
+                    stream->bytes_received_nack = 0;
+                }
+
                 stream->tunnel->up->upStream(stream->tunnel->up, stream_data);
 
                 if (nghttp2_session_get_stream_user_data(session, stream_id))
@@ -132,6 +163,17 @@ static int onDataChunkRecvCallback(nghttp2_session *session, uint8_t flags, int3
             stream->first_sent = true;
             stream_data->first = true;
         }
+        stream->bytes_received_nack += bufLen(buf);
+        if (stream->bytes_received_nack >= kMaxRecvBeforeAck)
+        {
+            nghttp2_nv nvs[1];
+            char       stri[32];
+            sprintf(stri, "%d", (int) stream->bytes_received_nack);
+            nvs[0] = makeNV("grpc-ack", stri);
+            nghttp2_submit_headers(con->session, NGHTTP2_FLAG_END_HEADERS, stream_id, NULL, &nvs[0], 1, NULL);
+            stream->bytes_received_nack = 0;
+        }
+
         stream->tunnel->up->upStream(stream->tunnel->up, stream_data);
     }
 
@@ -260,6 +302,12 @@ static bool trySendResponse(tunnel_t *self, http2_server_con_state_t *con, size_
         // HTTP2 DATA framehd
         con->state = kH2SendData;
 
+        http2_server_child_con_state_t *stream = nghttp2_session_get_stream_user_data(con->session, stream_id);
+        stream->bytes_sent_nack += bufLen(buf);
+        if (stream->bytes_sent_nack > kMaxSendBeforeAck)
+        {
+            pauseLineUpSide(stream->line);
+        }
         // LOGD("HTTP2 SEND_DATA_FRAME_HD...\n");
         if (con->content_type == kApplicationGrpc)
         {
@@ -478,7 +526,7 @@ api_result_t apiHttp2Server(tunnel_t *self, const char *msg)
 {
     (void) (self);
     (void) (msg);
-    return (api_result_t){0};
+    return (api_result_t) {0};
 }
 
 tunnel_t *destroyHttp2Server(tunnel_t *self)
@@ -490,5 +538,5 @@ tunnel_t *destroyHttp2Server(tunnel_t *self)
 
 tunnel_metadata_t getMetadataHttp2Server(void)
 {
-    return (tunnel_metadata_t){.version = 0001, .flags = 0x0};
+    return (tunnel_metadata_t) {.version = 0001, .flags = 0x0};
 }
diff --git a/tunnels/server/http2/types.h b/tunnels/server/http2/types.h
index bf134039..2144037c 100644
--- a/tunnels/server/http2/types.h
+++ b/tunnels/server/http2/types.h
@@ -24,6 +24,13 @@ typedef enum
     kH2RecvData,
 } http2_session_state;
 
+enum
+{
+
+    kMaxRecvBeforeAck = (1 << 16),
+    kMaxSendBeforeAck = (1 << 20)
+};
+
 typedef struct http2_server_child_con_state_s
 {
     struct http2_server_child_con_state_s *prev, *next;
@@ -35,6 +42,8 @@ typedef struct http2_server_child_con_state_s
     line_t                                *parent;
     line_t                                *line;
     tunnel_t                              *tunnel;
+    size_t                                 bytes_sent_nack;
+    size_t                                 bytes_received_nack;
 } http2_server_child_con_state_t;
 
 typedef struct http2_server_con_state_s