diff --git a/ryu/lib/rpc.py b/ryu/lib/rpc.py
index 6b8a0abf7..c1cea8159 100644
--- a/ryu/lib/rpc.py
+++ b/ryu/lib/rpc.py
@@ -62,7 +62,7 @@ def _create_msgid(self):
 
     def create_request(self, method, params):
         assert isinstance(method, str)
-        assert isinstance(params, list)
+        assert isinstance(params, (list, dict))
         msgid = self._create_msgid()
         return (self._packer.pack([MessageType.REQUEST, msgid, method,
                                   params]), msgid)
@@ -75,7 +75,7 @@ def create_response(self, msgid, error=None, result=None):
 
     def create_notification(self, method, params):
         assert isinstance(method, str)
-        assert isinstance(params, list)
+        assert isinstance(params, (list, dict))
         return self._packer.pack([MessageType.NOTIFY, method, params])
 
     def get_and_dispatch_messages(self, data, disp_table):
@@ -127,6 +127,7 @@ def __init__(self, sock, encoder=None, disp_table=None):
         self._notifications = deque()
         self._responses = {}
         self._incoming = 0  # number of incoming messages in our queues
+        self.closed_by_peer = False
 
     def selectable(self):
         rlist = [self._sock]
@@ -154,7 +155,7 @@ def block(self):
         select.select(rlist, wlist, rlist + wlist)
 
     def serve(self):
-        while True:
+        while not self.closed_by_peer:
             self.block()
             self.process()
 
@@ -194,6 +195,9 @@ def receive_messages(self, all=False):
             except IOError:
                 packet = None
             if not packet:
+                if packet is not None:
+                    # socket closed by peer
+                    self.closed_by_peer = True
                 break
             self._encoder.get_and_dispatch_messages(packet, self._table)
         return self._incoming > 0