diff --git a/connection.py b/connection.py
deleted file mode 100644
index e5aff45..0000000
--- a/connection.py
+++ /dev/null
@@ -1,73 +0,0 @@
-import socket
-import argparse
-import threading
-import random
-import time
-
-def handle_client(conn):
-    while True:
-        try:
-            num = random.randint(0, 100)
-            conn.send(f"number={num}".encode())
-            time.sleep(1)
-        except:
-            print("Disconnected.")
-            conn.close()
-            break
-
-class ServiceExplorationModule():
-    def __init__(self, host, port):
-        # UDP server
-        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
-        self.host = host
-        self.port = port
-
-        self.is_available = False
-
-    def listen(self):
-        self.sock.bind((self.host, self.port))
-        print(f"Exploration Server(UDP) listening on port {self.port}...")
-
-        while True:
-            data, addr = self.sock.recvfrom(1024)
-
-            if self.is_available:
-                if data.decode() == '[EXPLORE]':
-                    print(f"Receive exploration broadcast from {addr}")
-                    self.sock.sendto(self.host.encode(), addr)
-
-    def explore(self):
-        available_host = []
-
-        self.sock.settimeout(3)
-        self.sock.sendto('[EXPLORE]'.encode(), ('255.255.255.255', self.port))
-
-        while True:
-            try:
-                data, addr = self.sock.recvfrom(1024)
-                available_host.append(addr)
-                print(data.decode(), addr)
-            except:
-                # if socket timeout
-                break
-        return available_host
-
-if __name__ == '__main__':
-    parser = argparse.ArgumentParser()
-    parser.add_argument('type', type=str, help="'client' or 'server'", default='server')
-    parser.add_argument('--host', type=str, help="server's IPv4 address", default='0.0.0.0')
-    parser.add_argument('--port', type=int, help="server's listening port", default=8888)
-
-    args = parser.parse_args()
-    socket_type = args.type
-    host, port = args.host, args.port
-
-    service_explore = ServiceExplorationModule(host, port)
-    explore_service_thread = threading.Thread(target=service_explore.listen)
-    explore_service_thread.start()
-
-    if socket_type == 'client':
-        hosts = service_explore.explore()
-        print(hosts)
-    
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..9058904
--- /dev/null
+++ b/main.py
@@ -0,0 +1,21 @@
+import argparse
+import threading
+from src.communication import ServiceExplorationModule
+from src.parser import get_args
+
+if __name__ == '__main__':
+    args = get_args()
+
+    socket_type = args.type
+    host, port = args.host, args.port
+
+    # start Service Exploration Module
+    # let all client can know which IP address has our service so that it can link to.
+    service_explore = ServiceExplorationModule(host, port+1)
+    explore_service_thread = threading.Thread(target=service_explore.listen)
+    explore_service_thread.start()
+
+    if socket_type == 'client':
+        hosts = service_explore.explore()
+        print(hosts)
+
diff --git a/src/communication.py b/src/communication.py
new file mode 100644
index 0000000..ac8d00b
--- /dev/null
+++ b/src/communication.py
@@ -0,0 +1,42 @@
+import socket
+
+class ServiceExplorationModule():
+    def __init__(self, host, port):
+        # UDP server
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
+        self.host = host
+        self.port = port
+        self.IP = socket.gethostbyname(socket.gethostname())
+        self.is_available = True
+
+    def listen(self):
+        self.sock.bind((self.host, self.port))
+        print(f"Exploration Server(UDP) listening on {self.host}:{self.port}...")
+
+        while True:
+            data, addr = self.sock.recvfrom(1024)
+
+            if self.is_available:
+                if data.decode() == '[EXPLORE]':
+                    print(f"Receive exploration broadcast from {addr}")
+                    self.sock.sendto(self.IP.encode(), addr)
+
+    def explore(self):
+        available_host = []
+
+        client_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        client_sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
+
+        client_sock.settimeout(3)
+        client_sock.sendto('[EXPLORE]'.encode(), ('255.255.255.255', self.port))
+
+        while True:
+            try:
+                data, addr = client_sock.recvfrom(1024)
+                if addr[0] != self.IP:
+                    available_host.append(addr)
+            except:
+                # if socket timeout
+                break
+        return available_host
diff --git a/src/parser.py b/src/parser.py
new file mode 100644
index 0000000..c158307
--- /dev/null
+++ b/src/parser.py
@@ -0,0 +1,10 @@
+import argparse
+
+def get_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('type', type=str, help="'client' or 'server'", default='server')
+    parser.add_argument('--host', type=str, help="server's IPv4 address", default='0.0.0.0')
+    parser.add_argument('--port', type=int, help="server's listening port", default=8888)
+
+    args = parser.parse_args()
+    return args