diff --git a/FABulous/fabric_generator/file_parser.py b/FABulous/fabric_generator/file_parser.py
index 8c8cfed..78d08f1 100644
--- a/FABulous/fabric_generator/file_parser.py
+++ b/FABulous/fabric_generator/file_parser.py
@@ -349,6 +349,10 @@ def parseList(
         rightList = []
         expandListPorts(left, leftList)
         expandListPorts(right, rightList)
+        if len(leftList) != len(rightList):
+            raise ValueError(
+                f"List file {filePath} does not have the same number of source and sink ports."
+            )
         resultList += list(zip(leftList, rightList))
 
     result = list(dict.fromkeys(resultList))
diff --git a/FABulous/fabric_generator/utilities.py b/FABulous/fabric_generator/utilities.py
index b4da591..821abf8 100644
--- a/FABulous/fabric_generator/utilities.py
+++ b/FABulous/fabric_generator/utilities.py
@@ -20,13 +20,14 @@ def expandListPorts(port, PortList):
     Raises
     ------
     ValueError
-        If the port entry contains "[" without matching "]".
+        If the port entry contains "[" or "{" without matching closing
+        bracket "]"/"}".
     """
+    if port.count("[") != port.count("]") and port.count("{") != port.count("}"):
+        raise ValueError(f"Invalid port entry: {port}, mismatched brackets")
+
     # a leading '[' tells us that we have to expand the list
     if "[" in port:
-        if "]" not in port:
-            logger.error("Error in function ExpandListPorts: cannot find closing ]")
-            raise ValueError
         # port.find gives us the first occurrence index in a string
         left_index = port.find("[")
         right_index = port.find("]")
@@ -40,8 +41,20 @@ def expandListPorts(port, PortList):
             expandListPorts(ExpandListItem, PortList)
 
     else:
-        # print('DEBUG: else, just:',port)
-        PortList.append(port)
+        # Multiply ports by the number of multipliers, given in the curly braces.
+        # We let all curly braces in the port Expansion to be expanded and
+        # calculate the total number of ports to be added afterward, based on the number of multipliers.
+        # Also remove the multipliers from port name, before adding it to the list.
+        port = port.replace(" ", "")  # remove spaces
+        multipliers = re.findall(r"\{(\d+)\}", port)
+        portMultiplier = sum([int(m) for m in multipliers])
+        if portMultiplier != 0:
+            port = re.sub(r"\{(\d+)\}", "", port)
+            logger.debug(f"Port {port} has {portMultiplier} multipliers")
+            for i in range(portMultiplier):
+                PortList.append(port)
+        else:
+            PortList.append(port)
 
 
 # Default parameters (will be overwritten if defined in fabric between 'ParametersBegin' and 'ParametersEnd'
diff --git a/docs/source/fabric_definition.rst b/docs/source/fabric_definition.rst
index 0995599..aa6307b 100644
--- a/docs/source/fabric_definition.rst
+++ b/docs/source/fabric_definition.rst
@@ -429,6 +429,9 @@ Configurable connections are defined in either an adjacency list or an adjacency
 
 A switch matrix entry is specified by a line <output_port>,<input_port>.
 For convenience, it is possible to specify multiple ports though a list operator [item1|item2|...].
+There is also a multiplier {N}, where N is the number of times the port should be repeated.
+So a {4}N2BEG0 will be expanded to [N2BEG0|N2BEG0|N2BEG0|N2BEG0]
+
 For instance, the following line in a list file
 
 .. code-block:: python
@@ -468,7 +471,13 @@ A switch matrix multiplexer is modelled by having multiple connections for the s
 
    # the same in compact form:
    N2BEG[0|0|0|0],[N2END3|E2END2|S2END1|LB_O]
+   # or even more compact:
+   {4}N2BEG0,[N2END3|E2END2|S2END1|LB_O]
+
+For completion, the following expressions are all equivalent:
+.. code-block:: python
 
+  N2BEG[0|0|0|0] <=> {4}N2BEG0 <=> N2BEG[{4}0] <=> {2}N2BEG[0|0] <=> {2}N2BEG[{2}0] <=> [N2BEG0|N2BEG0|N2BEG0|N2BEG0]
 
 The ``INCLUDE`` keyword can also be used to include another list file in the current list file. For example: