diff --git a/src/class/net/ncm.h b/src/class/net/ncm.h
index c768192a5..cf4daf96c 100644
--- a/src/class/net/ncm.h
+++ b/src/class/net/ncm.h
@@ -2,6 +2,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2021, Ha Thach (tinyusb.org)
+ * Copyright (c) 2024, Hardy Griech
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,42 +30,47 @@
 #define _TUSB_NCM_H_
 
 #include "common/tusb_common.h"
-
+#include "lwipopts.h"
 
 #ifndef CFG_TUD_NCM_IN_NTB_MAX_SIZE
-    /// must be >> MTU
-    #define CFG_TUD_NCM_IN_NTB_MAX_SIZE        3200
+    #define CFG_TUD_NCM_IN_NTB_MAX_SIZE             (2 * TCP_MSS + 100)
 #endif
 #ifndef CFG_TUD_NCM_OUT_NTB_MAX_SIZE
-    /// must be >> MTU
-    #define CFG_TUD_NCM_OUT_NTB_MAX_SIZE       3200
+    #define CFG_TUD_NCM_OUT_NTB_MAX_SIZE            (2 * TCP_MSS + 100)
 #endif
 
 #ifndef CFG_TUD_NCM_OUT_NTB_N
-    /// number of ntb buffers for reception side
-    /// 1  - good performance
-    /// 2  - up to 30% more performance with iperf with small packets
-    /// >2 - no performance gain
-    #define CFG_TUD_NCM_OUT_NTB_N              2
+    /// number of NTB buffers for reception side
+    ///    1  - good performance
+    ///    2  - up to 30% more performance with iperf with small packets
+    ///    >2 - no performance gain
+    /// -> for performance optimizations this parameter could be increased with the cost of additional RAM requirements
+    #define CFG_TUD_NCM_OUT_NTB_N                   1
 #endif
 
 #ifndef CFG_TUD_NCM_IN_NTB_N
-    /// number of ntb buffers for transmission side
-    /// 1 - good performance but SystemView shows lost events (on load test)
-    /// 2 - up to 50% more performance with iperf with small packets, "tud_network_can_xmit: request blocked"
-    ///     happens from time to time with SystemView
-    /// 3 - "tud_network_can_xmit: request blocked" never happens
-    /// >2 - no performance gain
-    #define CFG_TUD_NCM_IN_NTB_N               3
+    /// number of NTB buffers for transmission side
+    ///    1 - good performance but SystemView shows lost events (on load test)
+    ///    2 - up to 50% more performance with iperf with small packets, "tud_network_can_xmit: request blocked"
+    ///        happens from time to time with SystemView
+    ///    3 - "tud_network_can_xmit: request blocked" never happens
+    ///    >2 - no performance gain
+    /// -> for performance optimizations this parameter could be increased with the cost of additional RAM requirements
+    #define CFG_TUD_NCM_IN_NTB_N                    1
 #endif
 
-#ifndef CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB
-    /// this is for the transmission size for allocation of \a ndp16_datagram_t
-    #define CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB  8
+#ifndef CFG_TUD_NCM_IN_MAX_DATAGRAMS_PER_NTB
+    /// this is for the transmission side for allocation of \a ndp16_datagram_t
+    #define CFG_TUD_NCM_IN_MAX_DATAGRAMS_PER_NTB    8
+#endif
+
+#ifndef CFG_TUD_NCM_OUT_MAX_DATAGRAMS_PER_NTB
+    /// this tells the host how many datagrams it is allowed to put into an NTB
+    #define CFG_TUD_NCM_OUT_MAX_DATAGRAMS_PER_NTB   6
 #endif
 
 #ifndef CFG_TUD_NCM_ALIGNMENT
-    #define CFG_TUD_NCM_ALIGNMENT              4
+    #define CFG_TUD_NCM_ALIGNMENT                   4
 #endif
 #if (CFG_TUD_NCM_ALIGNMENT != 4)
     #error "CFG_TUD_NCM_ALIGNMENT must be 4, otherwise the headers and start of datagrams have to be aligned (which they are currently not)"
@@ -136,7 +142,7 @@ typedef union TU_ATTR_PACKED {
     struct {
         nth16_t          nth;
         ndp16_t          ndp;
-        ndp16_datagram_t ndp_datagram[CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB + 1];
+        ndp16_datagram_t ndp_datagram[CFG_TUD_NCM_IN_MAX_DATAGRAMS_PER_NTB + 1];
     };
     uint8_t data[CFG_TUD_NCM_IN_NTB_MAX_SIZE];
 } xmit_ntb_t;
diff --git a/src/class/net/ncm_device.c b/src/class/net/ncm_device.c
index 829161865..40f70dc3f 100644
--- a/src/class/net/ncm_device.c
+++ b/src/class/net/ncm_device.c
@@ -1,8 +1,8 @@
 /*
  * The MIT License (MIT)
  *
- * Copyright (c) 2023 Hardy Griech
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ * Copyright (c) 2024 Hardy Griech
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -126,7 +126,7 @@ CFG_TUSB_MEM_SECTION CFG_TUSB_MEM_ALIGN tu_static const ntb_parameters_t ntb_par
         .wNdbOutDivisor          = 4,
         .wNdbOutPayloadRemainder = 0,
         .wNdbOutAlignment        = CFG_TUD_NCM_ALIGNMENT,
-        .wNtbOutMaxDatagrams     = 6                                     // 0=no limit
+        .wNtbOutMaxDatagrams     = CFG_TUD_NCM_OUT_MAX_DATAGRAMS_PER_NTB,
 };
 
 //-----------------------------------------------------------------------------
@@ -371,7 +371,7 @@ static bool xmit_requested_datagram_fits_into_current_ntb(uint16_t datagram_size
     if (ncm_interface.xmit_glue_ntb == NULL) {
         return false;
     }
-    if (ncm_interface.xmit_glue_ntb_datagram_ndx >= CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB) {
+    if (ncm_interface.xmit_glue_ntb_datagram_ndx >= CFG_TUD_NCM_IN_MAX_DATAGRAMS_PER_NTB) {
         return false;
     }
     if (ncm_interface.xmit_glue_ntb->nth.wBlockLength + datagram_size + XMIT_ALIGN_OFFSET(datagram_size) > CFG_TUD_NCM_OUT_NTB_MAX_SIZE) {