diff --git a/tools/pylibopenflow/pylib/of/network.py b/tools/pylibopenflow/pylib/of/network.py
new file mode 100644
index 0000000..6765a12
--- /dev/null
+++ b/tools/pylibopenflow/pylib/of/network.py
@@ -0,0 +1,191 @@
+"""This module holds the network.
+
+Copyright(C) 2009, Stanford University
+Date October 2009
+Created by ykk
+"""
+import random
+import openflow
+
+class network:
+    """Class holding information about OpenFlow network
+    """
+    def __init__(self):
+        """Initialize
+        """
+        ##List of switches
+        self.switches = []
+        ##Dictionary of links
+        self.links = {}
+        ##Reference to connections
+        self.connections = openflow.connections()
+
+    def add_switch(self, sw):
+        """Add switch to network
+        """
+        self.switches.append(sw)
+        self.connections.add_connection(sw, sw.connection)
+
+    def add_link(self, link):
+        """Add link to network
+        """
+        try:
+            self.links[link.switch1,link.switch2].append(link)
+        except KeyError:
+            self.links[link.switch1,link.switch2] = []
+            self.links[link.switch1,link.switch2].append(link)
+
+class link:
+    """Class to hold information about link
+
+    Copyright(C) 2009, Stanford University
+    Date November 2009
+    Created by ykk
+    """
+    def __init__(self, switch1, switch2):
+        """Initialize link between specified switches
+        """
+        ##Reference to first switch
+        self.switch1 = switch1
+        ##Reference to second switch
+        self.switch2 = switch2
+
+class switch:
+    """Class holding information about OpenFlow switch
+
+    Copyright(C) 2009, Stanford University
+    Date October 2009
+    Created by ykk
+    """
+    def __init__(self, miss_send_len=128,
+                 sock=None, dpid=None, n_buffers=100, n_tables=1,
+                 capability=None):
+        """Initialize switch
+        """
+        ##Socket to controller
+        self.sock = sock
+        ##Datapath id of switch
+        if (dpid != None):
+            self.datapath_id = dpid
+        else:
+            self.datapath_id = random.randrange(1, pow(2,64))
+        ##Number of buffers
+        self.n_buffers = n_buffers
+        ##Number of tables
+        self.n_tables= n_tables
+        ##Capabilities
+        if (isinstance(capability, switch_capabilities)):
+            self.capability = capability
+        else:
+            self.capability = switch_capabilities(miss_send_len)
+        ##Valid Actions
+        self.valid_actions = 0
+        ##List of port
+        self.port = []
+
+class switch_capabilities:
+    """Class to hold switch capabilities
+    """
+    def __init__(self, miss_send_len=128):
+        """Initialize
+
+        Copyright(C) 2009, Stanford University
+        Date October 2009
+        Created by ykk
+        """
+        ##Capabilities support by datapath
+        self.flow_stats = True
+        self.table_stats = True
+        self.port_stats = True
+        self.stp = True
+        self.multi_phy_tx = True
+        self.ip_resam = False
+        ##Switch config
+        self.send_exp = None
+        self.ip_frag = 0
+        self.miss_send_len = miss_send_len
+        ##Valid actions
+        self.act_output = True
+        self.act_set_vlan_vid = True
+        self.act_set_vlan_pcp = True
+        self.act_strip_vlan = True
+        self.act_set_dl_src = True
+        self.act_set_dl_dst = True
+        self.act_set_nw_src = True
+        self.act_set_nw_dst = True
+        self.act_set_tp_src = True
+        self.act_set_tp_dst = True
+        self.act_vendor = False
+
+    def get_capability(self, ofmsg):
+        """Return value for uint32_t capability field
+        """
+        value = 0
+        if (self.flow_stats):
+            value += ofmsg.get_value("OFPC_FLOW_STATS")
+        if (self.table_stats):
+            value += ofmsg.get_value("OFPC_TABLE_STATS")
+        if (self.port_stats):
+            value += ofmsg.get_value("OFPC_PORT_STATS")
+        if (self.stp):
+            value += ofmsg.get_value("OFPC_STP")
+        if (self.multi_phy_tx):
+            value += ofmsg.get_value("OFPC_MULTI_PHY_TX")
+        if (self.ip_resam):
+            value += ofmsg.get_value("OFPC_IP_REASM")
+        return value
+
+    def get_actions(self, ofmsg):
+        """Return value for uint32_t action field
+        """
+        value = 0
+        if (self.act_output):
+            value += (1 << (ofmsg.get_value("OFPAT_OUTPUT")+1))
+        if (self.act_set_vlan_vid):
+            value += (1 << (ofmsg.get_value("OFPAT_SET_VLAN_VID")+1))
+        if (self.act_set_vlan_pcp):
+            value += (1 << (ofmsg.get_value("OFPAT_SET_VLAN_PCP")+1))
+        if (self.act_strip_vlan):
+            value += (1 << (ofmsg.get_value("OFPAT_STRIP_VLAN")+1))
+        if (self.act_set_dl_src):
+            value += (1 << (ofmsg.get_value("OFPAT_SET_DL_SRC")+1))
+        if (self.act_set_dl_dst):
+            value += (1 << (ofmsg.get_value("OFPAT_SET_DL_DST")+1))
+        if (self.act_set_nw_src):
+            value += (1 << (ofmsg.get_value("OFPAT_SET_NW_SRC")+1))
+        if (self.act_set_nw_dst):
+            value += (1 << (ofmsg.get_value("OFPAT_SET_NW_DST")+1))
+        if (self.act_set_tp_src):
+            value += (1 << (ofmsg.get_value("OFPAT_SET_TP_SRC")+1))
+        if (self.act_set_tp_dst):
+            value += (1 << (ofmsg.get_value("OFPAT_SET_TP_DST")+1))
+        return value
+
+class port:
+    """Class to hold information about port
+    
+    Copyright(C) 2009, Stanford University
+    Date October 2009
+    Created by ykk
+    """
+    def __init__(self, port_no, stp=(2 << 8), hw_addr=None, name=""):
+        """Initialize
+        """
+        ##Port properties
+        self.port_no = port_no
+        if (hw_addr != None):
+            self.hw_addr = hw_addr
+        else:
+            self.hw_addr = random.randrange(1, pow(2,48))
+        self.name = name
+        ##Port config
+        self.port_down = False
+        self.no_stp = False
+        self.no_recv = False
+        self.no_recv_stp = False
+        self.no_flood = False
+        self.no_fwd = False
+        self.no_packet_in = False
+        #Port state
+        self.link_down = False
+        self.stp = stp