diff --git a/syndicate/mini/core.py b/syndicate/mini/core.py
index 8281a7c..2d9f609 100644
--- a/syndicate/mini/core.py
+++ b/syndicate/mini/core.py
@@ -119,6 +119,7 @@ class Connection(object):
         if protocol.Add.isClassOf(v): return self._lookup(v[0])._add(v[1])
         if protocol.Del.isClassOf(v): return self._lookup(v[0])._del(v[1])
         if protocol.Msg.isClassOf(v): return self._lookup(v[0])._msg(v[1])
+        if protocol.Ping.isClassOf(v): self._send(self._encode(protocol.Pong()))
 
     def _send(self, bs):
         raise Exception('subclassresponsibility')
diff --git a/syndicate/mini/protocol.py b/syndicate/mini/protocol.py
index 456d537..ce7a92a 100644
--- a/syndicate/mini/protocol.py
+++ b/syndicate/mini/protocol.py
@@ -11,6 +11,10 @@ Add = Record.makeConstructor('Add', 'endpointName captures')
 Del = Record.makeConstructor('Del', 'endpointName captures')
 Msg = Record.makeConstructor('Msg', 'endpointName captures')
 
+## Bidirectional
+Ping = Record.makeConstructor('Ping', '')
+Pong = Record.makeConstructor('Pong', '')
+
 ## Standard Syndicate constructors
 Observe = Record.makeConstructor('observe', 'specification')
 Capture = Record.makeConstructor('capture', 'specification')