diff --git a/sippy/b2bua_radius.py b/sippy/b2bua_radius.py
index 7334cfa..7815930 100755
--- a/sippy/b2bua_radius.py
+++ b/sippy/b2bua_radius.py
@@ -27,6 +27,7 @@
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import sys
+from functools import partial
 from os.path import dirname, join as p_join
 sys.path.append(p_join(dirname(sys.argv[0]), '..'))
 
@@ -151,7 +152,7 @@ def __init__(self, remote_ip, source, req_source, req_target, global_config, pas
         if '_allowed_pts' in self.global_config:
             self.uaA.on_remote_sdp_change = self.filter_SDP
 
-    def filter_SDP(self, body, done_cb):
+    def filter_SDP(self, body, done_cb, prev_orc = None):
         try:
             body.parse()
         except Exception as ex:
@@ -171,6 +172,8 @@ def filter_SDP(self, body, done_cb):
                 raise SdpParseError()
             if old_len > len(mbody.formats):
                 sect.optimize_a()
+        if prev_orc is not None:
+            return prev_orc(body, done_cb)
         return body
 
     def recvEvent(self, event, ua):
@@ -345,6 +348,9 @@ def placeOriginate(self, oroute):
             if body is not None:
                 body = body.getCopy()
             self.proxied = True
+        if '_allowed_pts' in self.global_config:
+            prev_orc = self.uaO.on_remote_sdp_change
+            self.uaO.on_remote_sdp_change = partial(self.filter_SDP, prev_orc=prev_orc)
         self.uaO.kaInterval = self.global_config['keepalive_orig']
         if 'group_timeout' in oroute.params:
             timeout, skipto = oroute.params['group_timeout']