diff --git a/gnpy/tools/cli_examples.py b/gnpy/tools/cli_examples.py
index 155d0042..0dd64710 100644
--- a/gnpy/tools/cli_examples.py
+++ b/gnpy/tools/cli_examples.py
@@ -410,7 +410,8 @@ def path_requests_run(args=None):
                         f'-', f'{rqs[i].blocking_reason}']
         except AttributeError:
             line = [f'{rqs[i].request_id}', f' {rqs[i].source} to {rqs[i].destination} : ', psnrb,
-                    psnr, f'{rqs[i].OSNR}', f'{rqs[i].tsp_mode}', f'{round(rqs[i].path_bandwidth * 1e-9,2)}',
+                    psnr, f'{rqs[i].OSNR + equipment["SI"]["default"].sys_margins}',
+                    f'{rqs[i].tsp_mode}', f'{round(rqs[i].path_bandwidth * 1e-9,2)}',
                     f'{ceil(rqs[i].path_bandwidth / rqs[i].bit_rate) }', f'({rqs[i].N},{rqs[i].M})']
         data.append(line)
 
diff --git a/gnpy/tools/json_io.py b/gnpy/tools/json_io.py
index 70bf6c1a..016d66dd 100644
--- a/gnpy/tools/json_io.py
+++ b/gnpy/tools/json_io.py
@@ -230,14 +230,6 @@ def load_equipment(filename):
     return _equipment_from_json(json_data, filename)
 
 
-def _update_trx_osnr(equipment):
-    """add sys_margins to all Transceivers OSNR values"""
-    for trx in equipment['Transceiver'].values():
-        for m in trx.mode:
-            m['OSNR'] = m['OSNR'] + equipment['SI']['default'].sys_margins
-    return equipment
-
-
 def _update_dual_stage(equipment):
     edfa_dict = equipment['Edfa']
     for edfa in edfa_dict.values():
@@ -298,7 +290,6 @@ def _equipment_from_json(json_data, filename):
                 equipment[key][subkey] = RamanFiber(**entry)
             else:
                 raise EquipmentConfigError(f'Unrecognized network element type "{key}"')
-    equipment = _update_trx_osnr(equipment)
     equipment = _update_dual_stage(equipment)
     _roadm_restrictions_sanity_check(equipment)
     return equipment
diff --git a/gnpy/topology/request.py b/gnpy/topology/request.py
index 28a88eb5..0e41572c 100644
--- a/gnpy/topology/request.py
+++ b/gnpy/topology/request.py
@@ -375,7 +375,8 @@ def propagate_and_optimize_mode(path, req, equipment):
                         path[-1].update_snr(this_mode['tx_osnr'], equipment['Roadm']['default'].add_drop_osnr)
                     else:
                         path[-1].update_snr(this_mode['tx_osnr'])
-                    if round(min(path[-1].snr + lin2db(this_br / (12.5e9))), 2) > this_mode['OSNR']:
+                    if round(min(path[-1].snr + lin2db(this_br / (12.5e9))), 2) \
+                            > this_mode['OSNR'] + equipment['SI']['default'].sys_margins:
                         return path, this_mode
                     else:
                         last_explored_mode = this_mode
@@ -1092,11 +1093,11 @@ def compute_path_with_disjunction(network, equipment, pathreqlist, pathlist):
                 # baud_rate was defined
                 propagate(total_path, pathreq, equipment)
                 temp_snr01nm = round(mean(total_path[-1].snr+lin2db(pathreq.baud_rate/(12.5e9))), 2)
-                if temp_snr01nm < pathreq.OSNR:
+                if temp_snr01nm < pathreq.OSNR + equipment['SI']['default'].sys_margins:
                     msg = f'\tWarning! Request {pathreq.request_id} computed path from' +\
                           f' {pathreq.source} to {pathreq.destination} does not pass with' +\
                           f' {pathreq.tsp_mode}\n\tcomputedSNR in 0.1nm = {temp_snr01nm} ' +\
-                          f'- required osnr {pathreq.OSNR}'
+                          f'- required osnr {pathreq.OSNR} + {equipment["SI"]["default"].sys_margins} margin'
                     print(msg)
                     LOGGER.warning(msg)
                     pathreq.blocking_reason = 'MODE_NOT_FEASIBLE'
@@ -1139,11 +1140,12 @@ def compute_path_with_disjunction(network, equipment, pathreqlist, pathlist):
                 propagated_reversed_path = rev_p
                 temp_snr01nm = round(mean(propagated_reversed_path[-1].snr +\
                                           lin2db(pathreq.baud_rate/(12.5e9))), 2)
-                if temp_snr01nm < pathreq.OSNR:
+                if temp_snr01nm < pathreq.OSNR + equipment['SI']['default'].sys_margins:
                     msg = f'\tWarning! Request {pathreq.request_id} computed path from' +\
                           f' {pathreq.source} to {pathreq.destination} does not pass with' +\
                           f' {pathreq.tsp_mode}\n' +\
-                          f'\tcomputedSNR in 0.1nm = {temp_snr01nm} - required osnr {pathreq.OSNR}'
+                          f'\tcomputedSNR in 0.1nm = {temp_snr01nm} -' \
+                          f' required osnr {pathreq.OSNR} + {equipment["SI"]["default"].sys_margins} margin'
                     print(msg)
                     LOGGER.warning(msg)
                     # TODO selection of mode should also be on reversed direction !!