Update path tracing logic (WIP)

netbox/dcim/models/cables.py

@@ -21,7 +21,7 @@ from utilities.fields import ColorField, GenericArrayForeignKey
 from utilities.querysets import RestrictedQuerySet
 from utilities.serialization import deserialize_object, serialize_object
 from wireless.models import WirelessLink
-from .device_components import FrontPort, PathEndpoint, RearPort
+from .device_components import FrontPort, PathEndpoint, RearPort, PortAssignment
 
 __all__ = (
     'Cable',
@@ -775,58 +775,83 @@ class CablePath(models.Model):
 
             if isinstance(remote_terminations[0], FrontPort):
                 # Follow FrontPorts to their corresponding RearPorts
-                rear_ports = RearPort.objects.filter(
-                    pk__in=[t.rear_port_id for t in remote_terminations]
-                )
-                if len(rear_ports) > 1 or rear_ports[0].positions > 1:
-                    position_stack.append([fp.rear_port_position for fp in remote_terminations])
-
-                terminations = rear_ports
-
-            elif isinstance(remote_terminations[0], RearPort):
-                if len(remote_terminations) == 1 and remote_terminations[0].positions == 1:
-                    front_ports = FrontPort.objects.filter(
-                        rear_port_id__in=[rp.pk for rp in remote_terminations],
-                        rear_port_position=1
-                    )
-                # Obtain the individual front ports based on the termination and all positions
-                elif len(remote_terminations) > 1 and position_stack:
+                if position_stack:
                     positions = position_stack.pop()
-
-                    # Ensure we have a number of positions equal to the amount of remote terminations
-                    if len(remote_terminations) != len(positions):
-                        raise UnsupportedCablePath(
-                            _("All positions counts within the path on opposite ends of links must match")
-                        )
-
-                    # Get our front ports
                     q_filter = Q()
                     for rt in remote_terminations:
                         position = positions.pop()
-                        q_filter |= Q(rear_port_id=rt.pk, rear_port_position=position)
-                    if q_filter is Q():
-                        raise UnsupportedCablePath(_("Remote termination position filter is missing"))
-                    front_ports = FrontPort.objects.filter(q_filter)
-                # Obtain the individual front ports based on the termination and position
-                elif position_stack:
-                    front_ports = FrontPort.objects.filter(
-                        rear_port_id=remote_terminations[0].pk,
-                        rear_port_position__in=position_stack.pop()
-                    )
-                # If all rear ports have a single position, we can just get the front ports
-                elif all([rp.positions == 1 for rp in remote_terminations]):
-                    front_ports = FrontPort.objects.filter(rear_port_id__in=[rp.pk for rp in remote_terminations])
-
-                    if len(front_ports) != len(remote_terminations):
-                        # Some rear ports does not have a front port
-                        is_split = True
-                        break
+                        q_filter |= Q(front_port=rt, front_port_position=position)
+                    port_assignments = PortAssignment.objects.filter(q_filter)
                 else:
-                    # No position indicated: path has split, so we stop at the RearPorts
-                    is_split = True
-                    break
+                    port_assignments = PortAssignment.objects.filter(front_port__in=remote_terminations)
 
-                terminations = front_ports
+                if not port_assignments:
+                    print('No front-to-rear port assignments found')
+                    break
+                position_stack.append([assignment.rear_port_position for assignment in port_assignments])
+                terminations = [assignment.rear_port for assignment in port_assignments]
+
+            elif isinstance(remote_terminations[0], RearPort):
+                # Follow RearPorts to their corresponding FrontPorts
+                if position_stack:
+                    positions = position_stack.pop()
+                    q_filter = Q()
+                    for rt in remote_terminations:
+                        position = positions.pop()
+                        q_filter |= Q(rear_port=rt, rear_port_position=position)
+                    port_assignments = PortAssignment.objects.filter(q_filter)
+                else:
+                    port_assignments = PortAssignment.objects.filter(rear_port__in=remote_terminations)
+
+                if not port_assignments:
+                    print('No rear-to-front port assignments found')
+                    break
+                position_stack.append([assignment.front_port_position for assignment in port_assignments])
+                terminations = [assignment.front_port for assignment in port_assignments]
+
+                # if len(remote_terminations) == 1 and remote_terminations[0].positions == 1:
+                #     front_ports = FrontPort.objects.filter(
+                #         rear_port_id__in=[rp.pk for rp in remote_terminations],
+                #         rear_port_position=1
+                #     )
+                # # Obtain the individual front ports based on the termination and all positions
+                # elif len(remote_terminations) > 1 and position_stack:
+                #     positions = position_stack.pop()
+                #
+                #     # Ensure we have a number of positions equal to the amount of remote terminations
+                #     if len(remote_terminations) != len(positions):
+                #         raise UnsupportedCablePath(
+                #             _("All positions counts within the path on opposite ends of links must match")
+                #         )
+                #
+                #     # Get our front ports
+                #     q_filter = Q()
+                #     for rt in remote_terminations:
+                #         position = positions.pop()
+                #         q_filter |= Q(rear_port_id=rt.pk, rear_port_position=position)
+                #     if q_filter is Q():
+                #         raise UnsupportedCablePath(_("Remote termination position filter is missing"))
+                #     front_ports = FrontPort.objects.filter(q_filter)
+                # # Obtain the individual front ports based on the termination and position
+                # elif position_stack:
+                #     front_ports = FrontPort.objects.filter(
+                #         rear_port_id=remote_terminations[0].pk,
+                #         rear_port_position__in=position_stack.pop()
+                #     )
+                # # If all rear ports have a single position, we can just get the front ports
+                # elif all([rp.positions == 1 for rp in remote_terminations]):
+                #     front_ports = FrontPort.objects.filter(rear_port_id__in=[rp.pk for rp in remote_terminations])
+                #
+                #     if len(front_ports) != len(remote_terminations):
+                #         # Some rear ports does not have a front port
+                #         is_split = True
+                #         break
+                # else:
+                #     # No position indicated: path has split, so we stop at the RearPorts
+                #     is_split = True
+                #     break
+                #
+                # terminations = front_ports
 
             elif isinstance(remote_terminations[0], CircuitTermination):
                 # Follow a CircuitTermination to its corresponding CircuitTermination (A to Z or vice versa)

netbox/dcim/tests/test_cablepaths.py

@@ -281,9 +281,13 @@ class LegacyCablePathTests(CablePathTestCase):
         """
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        PortAssignment.objects.create(
+            front_port=frontport1,
+            front_port_position=1,
+            rear_port=rearport1,
+            rear_port_position=1
         )
 
         # Create cable 1
@@ -340,9 +344,13 @@ class LegacyCablePathTests(CablePathTestCase):
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
         interface3 = Interface.objects.create(device=self.device, name='Interface 3')
         interface4 = Interface.objects.create(device=self.device, name='Interface 4')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        PortAssignment.objects.create(
+            front_port=frontport1,
+            front_port_position=1,
+            rear_port=rearport1,
+            rear_port_position=1
         )
 
         # Create cable 1
@@ -403,18 +411,24 @@ class LegacyCablePathTests(CablePathTestCase):
         interface4 = Interface.objects.create(device=self.device, name='Interface 4')
         rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4)
         rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=4)
-        frontport1_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport1_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:2', rear_port=rearport1, rear_port_position=2
-        )
-        frontport2_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:1', rear_port=rearport2, rear_port_position=1
-        )
-        frontport2_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:2', rear_port=rearport2, rear_port_position=2
-        )
+        frontport1_1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1')
+        frontport1_2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2')
+        frontport2_1 = FrontPort.objects.create(device=self.device, name='Front Port 2:1')
+        frontport2_2 = FrontPort.objects.create(device=self.device, name='Front Port 2:2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1_1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport1_2, front_port_position=1, rear_port=rearport1, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport2_1, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2_2, front_port_position=1, rear_port=rearport2, rear_port_position=2,
+            ),
+        ])
 
         # Create cables 1-2
         cable1 = Cable(
@@ -521,18 +535,24 @@ class LegacyCablePathTests(CablePathTestCase):
         interface8 = Interface.objects.create(device=self.device, name='Interface 8')
         rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4)
         rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=4)
-        frontport1_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport1_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:2', rear_port=rearport1, rear_port_position=2
-        )
-        frontport2_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:1', rear_port=rearport2, rear_port_position=1
-        )
-        frontport2_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:2', rear_port=rearport2, rear_port_position=2
-        )
+        frontport1_1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1')
+        frontport1_2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2')
+        frontport2_1 = FrontPort.objects.create(device=self.device, name='Front Port 2:1')
+        frontport2_2 = FrontPort.objects.create(device=self.device, name='Front Port 2:2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1_1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport1_2, front_port_position=1, rear_port=rearport1, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport2_1, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2_2, front_port_position=1, rear_port=rearport2, rear_port_position=2,
+            ),
+        ])
 
         # Create cables 1-2
         cable1 = Cable(
@@ -680,27 +700,35 @@ class LegacyCablePathTests(CablePathTestCase):
         interface3 = Interface.objects.create(device=self.device, name='Interface 3')
         interface4 = Interface.objects.create(device=self.device, name='Interface 4')
         rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3', positions=1)
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3')
         rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4', positions=4)
-        frontport1_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport1_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:2', rear_port=rearport1, rear_port_position=2
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
-        frontport3 = FrontPort.objects.create(
-            device=self.device, name='Front Port 3', rear_port=rearport3, rear_port_position=1
-        )
-        frontport4_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 4:1', rear_port=rearport4, rear_port_position=1
-        )
-        frontport4_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 4:2', rear_port=rearport4, rear_port_position=2
-        )
+        frontport1_1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1')
+        frontport1_2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        frontport3 = FrontPort.objects.create(device=self.device, name='Front Port 3')
+        frontport4_1 = FrontPort.objects.create(device=self.device, name='Front Port 4:1')
+        frontport4_2 = FrontPort.objects.create(device=self.device, name='Front Port 4:2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1_1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport1_2, front_port_position=1, rear_port=rearport1, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3, front_port_position=1, rear_port=rearport3, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport4_1, front_port_position=1, rear_port=rearport4, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport4_2, front_port_position=1, rear_port=rearport4, rear_port_position=2,
+            ),
+        ])
 
         # Create cables 1-2, 6-7
         cable1 = Cable(
@@ -801,30 +829,40 @@ class LegacyCablePathTests(CablePathTestCase):
         rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=4)
         rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3', positions=4)
         rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4', positions=4)
-        frontport1_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport1_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:2', rear_port=rearport1, rear_port_position=2
-        )
-        frontport2_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:1', rear_port=rearport2, rear_port_position=1
-        )
-        frontport2_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:2', rear_port=rearport2, rear_port_position=2
-        )
-        frontport3_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 3:1', rear_port=rearport3, rear_port_position=1
-        )
-        frontport3_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 3:2', rear_port=rearport3, rear_port_position=2
-        )
-        frontport4_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 4:1', rear_port=rearport4, rear_port_position=1
-        )
-        frontport4_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 4:2', rear_port=rearport4, rear_port_position=2
-        )
+        frontport1_1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1')
+        frontport1_2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2')
+        frontport2_1 = FrontPort.objects.create(device=self.device, name='Front Port 2:1')
+        frontport2_2 = FrontPort.objects.create(device=self.device, name='Front Port 2:2')
+        frontport3_1 = FrontPort.objects.create(device=self.device, name='Front Port 3:1')
+        frontport3_2 = FrontPort.objects.create(device=self.device, name='Front Port 3:2')
+        frontport4_1 = FrontPort.objects.create(device=self.device, name='Front Port 4:1')
+        frontport4_2 = FrontPort.objects.create(device=self.device, name='Front Port 4:2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1_1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport1_2, front_port_position=1, rear_port=rearport1, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport2_1, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2_2, front_port_position=1, rear_port=rearport2, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport3_1, front_port_position=1, rear_port=rearport3, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3_2, front_port_position=1, rear_port=rearport3, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport4_1, front_port_position=1, rear_port=rearport4, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport4_2, front_port_position=1, rear_port=rearport4, rear_port_position=2,
+            ),
+        ])
 
         # Create cables 1-3, 6-8
         cable1 = Cable(
@@ -928,23 +966,30 @@ class LegacyCablePathTests(CablePathTestCase):
         interface3 = Interface.objects.create(device=self.device, name='Interface 3')
         interface4 = Interface.objects.create(device=self.device, name='Interface 4')
         rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 5', positions=1)
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 5')
         rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=4)
-        frontport1_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport1_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:2', rear_port=rearport1, rear_port_position=2
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 5', rear_port=rearport2, rear_port_position=1
-        )
-        frontport3_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:1', rear_port=rearport3, rear_port_position=1
-        )
-        frontport3_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:2', rear_port=rearport3, rear_port_position=2
-        )
+        frontport1_1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1')
+        frontport1_2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 5')
+        frontport3_1 = FrontPort.objects.create(device=self.device, name='Front Port 2:1')
+        frontport3_2 = FrontPort.objects.create(device=self.device, name='Front Port 2:2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1_1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport1_2, front_port_position=1, rear_port=rearport1, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3_1, front_port_position=1, rear_port=rearport3, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3_2, front_port_position=1, rear_port=rearport3, rear_port_position=2,
+            ),
+        ])
 
         # Create cables 1-2, 5-6
         cable1 = Cable(
@@ -1033,12 +1078,16 @@ class LegacyCablePathTests(CablePathTestCase):
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
         interface3 = Interface.objects.create(device=self.device, name='Interface 3')
         rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4)
-        frontport1_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport1_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:2', rear_port=rearport1, rear_port_position=2
-        )
+        frontport1_1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1')
+        frontport1_2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1_1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport1_2, front_port_position=1, rear_port=rearport1, rear_port_position=2,
+            ),
+        ])
 
         # Create cables 1
         cable1 = Cable(
@@ -1098,10 +1147,11 @@ class LegacyCablePathTests(CablePathTestCase):
         [IF1] --C1-- [FP1] [RP1] --C2-- [RP2]
         """
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        PortAssignment.objects.create(
+            front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
         )
 
         # Create cables
@@ -1413,18 +1463,24 @@ class LegacyCablePathTests(CablePathTestCase):
         interface4 = Interface.objects.create(device=self.device, name='Interface 4')
         rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4)
         rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=4)
-        frontport1_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport1_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:2', rear_port=rearport1, rear_port_position=2
-        )
-        frontport2_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:1', rear_port=rearport2, rear_port_position=1
-        )
-        frontport2_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:2', rear_port=rearport2, rear_port_position=2
-        )
+        frontport1_1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1')
+        frontport1_2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2')
+        frontport2_1 = FrontPort.objects.create(device=self.device, name='Front Port 2:1')
+        frontport2_2 = FrontPort.objects.create(device=self.device, name='Front Port 2:2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1_1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport1_2, front_port_position=1, rear_port=rearport1, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport2_1, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2_2, front_port_position=1, rear_port=rearport2, rear_port_position=2,
+            ),
+        ])
         circuittermination1 = CircuitTermination.objects.create(
             circuit=self.circuit,
             termination=self.site,
@@ -1601,22 +1657,28 @@ class LegacyCablePathTests(CablePathTestCase):
         """
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3', positions=1)
-        rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
-        frontport3 = FrontPort.objects.create(
-            device=self.device, name='Front Port 3', rear_port=rearport3, rear_port_position=1
-        )
-        frontport4 = FrontPort.objects.create(
-            device=self.device, name='Front Port 4', rear_port=rearport4, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3')
+        rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        frontport3 = FrontPort.objects.create(device=self.device, name='Front Port 3')
+        frontport4 = FrontPort.objects.create(device=self.device, name='Front Port 4')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3, front_port_position=1, rear_port=rearport3, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport4, front_port_position=1, rear_port=rearport4, rear_port_position=1,
+            ),
+        ])
 
         # Create cables 1-2
         cable1 = Cable(
@@ -1688,30 +1750,40 @@ class LegacyCablePathTests(CablePathTestCase):
         interface4 = Interface.objects.create(device=self.device, name='Interface 4')
         rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4)
         rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=4)
-        frontport1_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport1_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:2', rear_port=rearport1, rear_port_position=2
-        )
-        frontport1_3 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:3', rear_port=rearport1, rear_port_position=3
-        )
-        frontport1_4 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1:4', rear_port=rearport1, rear_port_position=4
-        )
-        frontport2_1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:1', rear_port=rearport2, rear_port_position=1
-        )
-        frontport2_2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:2', rear_port=rearport2, rear_port_position=2
-        )
-        frontport2_3 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:3', rear_port=rearport2, rear_port_position=3
-        )
-        frontport2_4 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2:4', rear_port=rearport2, rear_port_position=4
-        )
+        frontport1_1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1')
+        frontport1_2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2')
+        frontport1_3 = FrontPort.objects.create(device=self.device, name='Front Port 1:3')
+        frontport1_4 = FrontPort.objects.create(device=self.device, name='Front Port 1:4')
+        frontport2_1 = FrontPort.objects.create(device=self.device, name='Front Port 2:1')
+        frontport2_2 = FrontPort.objects.create(device=self.device, name='Front Port 2:2')
+        frontport2_3 = FrontPort.objects.create(device=self.device, name='Front Port 2:3')
+        frontport2_4 = FrontPort.objects.create(device=self.device, name='Front Port 2:4')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1_1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport1_2, front_port_position=1, rear_port=rearport1, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport1_3, front_port_position=1, rear_port=rearport1, rear_port_position=3,
+            ),
+            PortAssignment(
+                front_port=frontport1_4, front_port_position=1, rear_port=rearport1, rear_port_position=4,
+            ),
+            PortAssignment(
+                front_port=frontport2_1, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2_2, front_port_position=1, rear_port=rearport2, rear_port_position=2,
+            ),
+            PortAssignment(
+                front_port=frontport2_3, front_port_position=1, rear_port=rearport2, rear_port_position=3,
+            ),
+            PortAssignment(
+                front_port=frontport2_4, front_port_position=1, rear_port=rearport2, rear_port_position=4,
+            ),
+        ])
 
         # Create cables 1-2
         cable1 = Cable(
@@ -1858,22 +1930,28 @@ class LegacyCablePathTests(CablePathTestCase):
         """
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3', positions=1)
-        rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
-        frontport3 = FrontPort.objects.create(
-            device=self.device, name='Front Port 3', rear_port=rearport3, rear_port_position=1
-        )
-        frontport4 = FrontPort.objects.create(
-            device=self.device, name='Front Port 4', rear_port=rearport4, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3')
+        rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        frontport3 = FrontPort.objects.create(device=self.device, name='Front Port 3')
+        frontport4 = FrontPort.objects.create(device=self.device, name='Front Port 4')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3, front_port_position=1, rear_port=rearport3, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport4, front_port_position=1, rear_port=rearport4, rear_port_position=1,
+            ),
+        ])
 
         cable2 = Cable(
             a_terminations=[rearport1],
@@ -1937,22 +2015,28 @@ class LegacyCablePathTests(CablePathTestCase):
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
         interface3 = Interface.objects.create(device=self.device, name='Interface 3')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3', positions=1)
-        rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
-        frontport3 = FrontPort.objects.create(
-            device=self.device, name='Front Port 3', rear_port=rearport3, rear_port_position=1
-        )
-        frontport4 = FrontPort.objects.create(
-            device=self.device, name='Front Port 4', rear_port=rearport4, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3')
+        rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        frontport3 = FrontPort.objects.create(device=self.device, name='Front Port 3')
+        frontport4 = FrontPort.objects.create(device=self.device, name='Front Port 4')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3, front_port_position=1, rear_port=rearport3, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport4, front_port_position=1, rear_port=rearport4, rear_port_position=1,
+            ),
+        ])
 
         cable2 = Cable(
             a_terminations=[rearport1],
@@ -2033,30 +2117,38 @@ class LegacyCablePathTests(CablePathTestCase):
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
         interface3 = Interface.objects.create(device=self.device, name='Interface 3')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3', positions=1)
-        rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4', positions=1)
-        rearport5 = RearPort.objects.create(device=self.device, name='Rear Port 5', positions=1)
-        rearport6 = RearPort.objects.create(device=self.device, name='Rear Port 6', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
-        frontport3 = FrontPort.objects.create(
-            device=self.device, name='Front Port 3', rear_port=rearport3, rear_port_position=1
-        )
-        frontport4 = FrontPort.objects.create(
-            device=self.device, name='Front Port 4', rear_port=rearport4, rear_port_position=1
-        )
-        frontport5 = FrontPort.objects.create(
-            device=self.device, name='Front Port 5', rear_port=rearport5, rear_port_position=1
-        )
-        frontport6 = FrontPort.objects.create(
-            device=self.device, name='Front Port 6', rear_port=rearport6, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        rearport3 = RearPort.objects.create(device=self.device, name='Rear Port 3')
+        rearport4 = RearPort.objects.create(device=self.device, name='Rear Port 4')
+        rearport5 = RearPort.objects.create(device=self.device, name='Rear Port 5')
+        rearport6 = RearPort.objects.create(device=self.device, name='Rear Port 6')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        frontport3 = FrontPort.objects.create(device=self.device, name='Front Port 3')
+        frontport4 = FrontPort.objects.create(device=self.device, name='Front Port 4')
+        frontport5 = FrontPort.objects.create(device=self.device, name='Front Port 5')
+        frontport6 = FrontPort.objects.create(device=self.device, name='Front Port 6')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3, front_port_position=1, rear_port=rearport3, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport4, front_port_position=1, rear_port=rearport4, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport5, front_port_position=1, rear_port=rearport5, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport6, front_port_position=1, rear_port=rearport6, rear_port_position=1,
+            ),
+        ])
 
         cable2 = Cable(
             a_terminations=[rearport1],
@@ -2155,14 +2247,18 @@ class LegacyCablePathTests(CablePathTestCase):
         """
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+        ])
 
         cable1 = Cable(
             a_terminations=[interface1],
@@ -2200,14 +2296,18 @@ class LegacyCablePathTests(CablePathTestCase):
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
         interface3 = Interface.objects.create(device=self.device, name='Interface 3')
         interface4 = Interface.objects.create(device=self.device, name='Interface 4')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+        ])
 
         # Create cables
         cable1 = Cable(
@@ -2246,14 +2346,18 @@ class LegacyCablePathTests(CablePathTestCase):
         """
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+        ])
 
         # Create cable 2
         cable2 = Cable(
@@ -2299,10 +2403,13 @@ class LegacyCablePathTests(CablePathTestCase):
         """
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+        ])
 
         # Create cables 1 and 2
         cable1 = Cable(
@@ -2404,22 +2511,28 @@ class LegacyCablePathTests(CablePathTestCase):
         )
         interface1 = Interface.objects.create(device=self.device, name='Interface 1')
         interface2 = Interface.objects.create(device=self.device, name='Interface 2')
-        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=1)
-        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=1)
-        rearport3 = RearPort.objects.create(device=device, name='Rear Port 3', positions=1)
-        rearport4 = RearPort.objects.create(device=device, name='Rear Port 4', positions=1)
-        frontport1 = FrontPort.objects.create(
-            device=self.device, name='Front Port 1', rear_port=rearport1, rear_port_position=1
-        )
-        frontport2 = FrontPort.objects.create(
-            device=self.device, name='Front Port 2', rear_port=rearport2, rear_port_position=1
-        )
-        frontport3 = FrontPort.objects.create(
-            device=device, name='Front Port 3', rear_port=rearport3, rear_port_position=1
-        )
-        frontport4 = FrontPort.objects.create(
-            device=device, name='Front Port 4', rear_port=rearport4, rear_port_position=1
-        )
+        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
+        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
+        rearport3 = RearPort.objects.create(device=device, name='Rear Port 3')
+        rearport4 = RearPort.objects.create(device=device, name='Rear Port 4')
+        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
+        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
+        frontport3 = FrontPort.objects.create(device=self.device, name='Front Port 3')
+        frontport4 = FrontPort.objects.create(device=self.device, name='Front Port 4')
+        PortAssignment.objects.bulk_create([
+            PortAssignment(
+                front_port=frontport1, front_port_position=1, rear_port=rearport1, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport2, front_port_position=1, rear_port=rearport2, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport3, front_port_position=1, rear_port=rearport3, rear_port_position=1,
+            ),
+            PortAssignment(
+                front_port=frontport4, front_port_position=1, rear_port=rearport4, rear_port_position=1,
+            ),
+        ])
 
         cable2 = Cable(
             a_terminations=[rearport1],