diff --git a/openbsc/contrib/gb-proxy-unblock-bug.py b/openbsc/contrib/gb-proxy-unblock-bug.py
new file mode 100755
index 0000000..5a6b587
--- /dev/null
+++ b/openbsc/contrib/gb-proxy-unblock-bug.py
@@ -0,0 +1,59 @@
+#!/usr/bin/env python
+
+"""
+demonstrate a unblock bug on the GB Proxy..
+"""
+
+bts_ns_reset = "\x02\x00\x81\x01\x01\x82\x1f\xe7\x04\x82\x1f\xe7"
+ns_reset_ack = "\x03\x01\x82\x1f\xe7\x04\x82\x1f\xe7"
+
+bts_ns_unblock = "\x06"
+ns_unblock_ack = "\x07"
+
+bts_bvc_reset_0 = "\x00\x00\x00\x00\x22\x04\x82\x00\x00\x07\x81\x03\x3b\x81\x02"
+ns_bvc_reset_0_ack = "\x00\x00\x00\x00\x23\x04\x82\x00\x00"
+
+bts_bvc_reset_8167 = "\x00\x00\x00\x00\x22\x04\x82\x1f\xe7\x07\x81\x08\x08\x88\x72\xf4\x80\x10\x1c\x00\x9c\x40"
+
+
+import socket
+socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+socket.bind(("0.0.0.0", 0))
+socket.setblocking(1)
+
+def send_and_receive(packet, port):
+    socket.sendto(packet, ("127.0.0.1", port))
+
+    try:
+        data, addr = socket.recvfrom(4096)
+    except socket.error, e:
+        print "ERROR", e
+        import sys
+        sys.exit(0)
+    return data
+
+#send stuff once
+import sys
+port = int(sys.argv[1])
+print "Sending data to port: %d" % port
+
+
+res = send_and_receive(bts_ns_reset, port)
+if res != ns_reset_ack:
+    print "Failed to get the reset ack"
+    sys.exit(-1)
+
+res = send_and_receive(bts_ns_unblock, port)
+if res != ns_unblock_ack:
+    print "Failed to get the unblock ack"
+    sys.exit(-1)
+
+res = send_and_receive(bts_bvc_reset_0, port)
+if res != ns_bvc_reset_0_ack:
+    print "Failed to get NS BVCI=0 reset ack"
+    sys.exit(-1)
+
+import time
+time.sleep(3)
+res = send_and_receive(bts_bvc_reset_8167, port)
+print "Send all messages... check wireshark for the last response"