diff --git a/src/osmo_gsm_tester/osmo_bsc.py b/src/osmo_gsm_tester/osmo_bsc.py
index ec9c3b8..4160527 100644
--- a/src/osmo_gsm_tester/osmo_bsc.py
+++ b/src/osmo_gsm_tester/osmo_bsc.py
@@ -32,6 +32,7 @@
         self.process = None
         self.encryption = None
         self.rsl_ip = None
+        self.use_osmux = "off"
         self.suite_run = suite_run
         self.ip_address = ip_address
         self.bts = []
@@ -90,6 +91,7 @@
         else:
             encryption_vty = util.encryption2osmovty(values['bsc']['net']['encryption'])
         config.overlay(values, dict(bsc=dict(net=dict(encryption=encryption_vty))))
+        config.overlay(values, dict(bsc=dict(use_osmux=self.use_osmux)))
 
         if self.rsl_ip is not None:
             config.overlay(values, dict(bsc=dict(net=dict(rsl_ip=self.rsl_ip))))
@@ -113,6 +115,15 @@
         other external entities to test the RSL path, such as TTCN3 tests.'''
         self.rsl_ip = ip_addr
 
+    def set_use_osmux(self, use=False, force=False):
+        if not use:
+            self.use_osmux = "off"
+        else:
+            if not force:
+                self.use_osmux = "on"
+            else:
+                self.use_osmux = "only"
+
     def bts_add(self, bts):
         self.bts.append(bts)
         bts.set_bsc(self)
diff --git a/src/osmo_gsm_tester/osmo_mgw.py b/src/osmo_gsm_tester/osmo_mgw.py
index ca7bd51..ea8e652 100644
--- a/src/osmo_gsm_tester/osmo_mgw.py
+++ b/src/osmo_gsm_tester/osmo_mgw.py
@@ -31,6 +31,7 @@
         self.process = None
         self.suite_run = suite_run
         self.ip_address = ip_address
+        self.use_osmux = "off"
 
     def start(self):
         self.log('Starting osmo-mgw')
@@ -63,7 +64,11 @@
 
         values = dict(mgw=config.get_defaults('mgw'))
         config.overlay(values, self.suite_run.config())
-        config.overlay(values, dict(mgw=dict(ip_address=self.ip_address)))
+        config.overlay(values, { 'mgw': {
+                                        'ip_address': self.ip_address,
+                                        'use_osmux': self.use_osmux
+                                        }
+                                })
 
         self.dbg('MGW CONFIG:\n' + pprint.pformat(values))
 
@@ -81,4 +86,14 @@
     def running(self):
         return not self.process.terminated()
 
+    def set_use_osmux(self, use=False, force=False):
+        if not use:
+            self.use_osmux = "off"
+        else:
+            if not force:
+                self.use_osmux = "on"
+            else:
+                self.use_osmux = "only"
+
+
 # vim: expandtab tabstop=4 shiftwidth=4
diff --git a/src/osmo_gsm_tester/osmo_msc.py b/src/osmo_gsm_tester/osmo_msc.py
index 192926c..51f50c4 100644
--- a/src/osmo_gsm_tester/osmo_msc.py
+++ b/src/osmo_gsm_tester/osmo_msc.py
@@ -32,6 +32,7 @@
         self.config = None
         self.encryption = None
         self.authentication = None
+        self.use_osmux = "off"
         self.suite_run = suite_run
         self.ip_address = ip_address
         self.hlr = hlr
@@ -84,6 +85,7 @@
         config.overlay(values, dict(msc=dict(net=dict(encryption=encryption_vty))))
         if self.authentication is not None:
             config.overlay(values, dict(msc=dict(net=dict(authentication=self.authentication))))
+        config.overlay(values, dict(msc=dict(use_osmux=self.use_osmux)))
 
 
         self.config = values
@@ -107,6 +109,15 @@
             return
         self.authentication = "required" if val else "optional"
 
+    def set_use_osmux(self, use=False, force=False):
+        if not use:
+            self.use_osmux = "off"
+        else:
+            if not force:
+                self.use_osmux = "on"
+            else:
+                self.use_osmux = "only"
+
     def mcc(self):
         return self.config['msc']['net']['mcc']
 
diff --git a/src/osmo_gsm_tester/templates/osmo-bsc.cfg.tmpl b/src/osmo_gsm_tester/templates/osmo-bsc.cfg.tmpl
index 53e683b..572e765 100644
--- a/src/osmo_gsm_tester/templates/osmo-bsc.cfg.tmpl
+++ b/src/osmo_gsm_tester/templates/osmo-bsc.cfg.tmpl
@@ -118,5 +118,6 @@
  amr-config 5_90k allowed
  amr-config 5_15k forbidden
  amr-config 4_75k forbidden
+ osmux ${bsc.use_osmux}
  msc-addr msc_remote
  bsc-addr bsc_local
diff --git a/src/osmo_gsm_tester/templates/osmo-mgw.cfg.tmpl b/src/osmo_gsm_tester/templates/osmo-mgw.cfg.tmpl
index 9e338e1..f91ab30 100644
--- a/src/osmo_gsm_tester/templates/osmo-mgw.cfg.tmpl
+++ b/src/osmo_gsm_tester/templates/osmo-mgw.cfg.tmpl
@@ -14,3 +14,4 @@
  number endpoints 31
  rtcp-omit
  rtp-accept-all 1
+ osmux ${mgw.use_osmux}
diff --git a/src/osmo_gsm_tester/templates/osmo-msc.cfg.tmpl b/src/osmo_gsm_tester/templates/osmo-msc.cfg.tmpl
index b370d5e..31c57d3 100644
--- a/src/osmo_gsm_tester/templates/osmo-msc.cfg.tmpl
+++ b/src/osmo_gsm_tester/templates/osmo-msc.cfg.tmpl
@@ -28,6 +28,7 @@
  mgw local-ip ${msc.ip_address.addr}
  mgw endpoint-range 1 31
  mgw bts-base 8000
+ osmux ${msc.use_osmux}
  assign-tmsi
  cs7-instance-iu 0
  cs7-instance-a 0