diff --git a/coretk/coretk/coreclient.py b/coretk/coretk/coreclient.py
index 46d1cdad..b75b66ed 100644
--- a/coretk/coretk/coreclient.py
+++ b/coretk/coretk/coreclient.py
@@ -327,6 +327,7 @@ class CoreClient:
             emane_config = {x: self.emane_config[x].value for x in self.emane_config}
         else:
             emane_config = None
+        print(links)
         response = self.client.start_session(
             self.session_id,
             nodes,
@@ -341,7 +342,7 @@ class CoreClient:
             file_configs,
         )
         logging.debug("Start session %s, result: %s", self.session_id, response.result)
-        print(self.client.get_session(self.session_id))
+        # print(self.client.get_session(self.session_id))
 
     def stop_session(self):
         response = self.client.stop_session(session_id=self.session_id)
diff --git a/coretk/coretk/status.py b/coretk/coretk/status.py
index dde16cd8..2a160457 100644
--- a/coretk/coretk/status.py
+++ b/coretk/coretk/status.py
@@ -1,4 +1,5 @@
 "status bar"
+import time
 from tkinter import ttk
 
 
@@ -12,6 +13,7 @@ class StatusBar(ttk.Frame):
         self.cpu_usage = None
         self.memory = None
         self.emulation_light = None
+        self.running = False
         self.draw()
 
     def draw(self):
@@ -27,3 +29,16 @@ class StatusBar(ttk.Frame):
         self.cpu_usage.grid(row=0, column=2)
         self.emulation_light = ttk.Label(self, text="emulation light")
         self.emulation_light.grid(row=0, column=3)
+
+    def processing(self):
+        self.running = True
+        texts = ["Processing.", "Processing..", "Processing...", "Processing...."]
+        i = 0
+        while self.running is True:
+            self.status.config(text=texts[i % 4])
+            self.app.master.update()
+            i = i + 1
+            time.sleep(0.3)
+            print("running")
+        print("thread finish")
+        # self.status.config(text="status")
diff --git a/coretk/coretk/toolbar.py b/coretk/coretk/toolbar.py
index 834f7b39..648a2d8c 100644
--- a/coretk/coretk/toolbar.py
+++ b/coretk/coretk/toolbar.py
@@ -1,4 +1,5 @@
 import logging
+import threading
 import tkinter as tk
 from functools import partial
 from tkinter import ttk
@@ -197,12 +198,21 @@ class Toolbar(ttk.Frame):
         """
         logging.debug("clicked start button")
         self.master.config(cursor="watch")
+        status_thread = threading.Thread(target=self.app.statusbar.processing)
+        status_thread.start()
         self.master.update()
         self.app.canvas.mode = GraphMode.SELECT
         self.app.core.start_session()
         self.runtime_frame.tkraise()
         self.master.config(cursor="")
 
+        self.app.statusbar.running = False
+        if status_thread.is_alive():
+            print("still running")
+        status_thread.join()
+        print("thread terminate")
+        self.app.statusbar.status.config(text="status")
+
     def click_link(self):
         logging.debug("Click LINK button")
         self.design_select(self.link_button)