add smpp_test to generate SMS load via SMPP interface

It's not really related to MNCC, but in lack of a better suitable
repository, I'll commit it here for the time being.

smpp_test.py

@@ -0,0 +1,52 @@
+#!/usr/bin/python
+import logging
+import sys
+
+import smpplib.gsm
+import smpplib.client
+import smpplib.consts
+
+# This is a small script using https://github.com/podshumok/python-smpplib
+# to generate some SMS load on OsmoNITB via its SMPP interface
+
+# if you want to know what's happening
+logging.basicConfig(level='DEBUG')
+
+def send_message(dest, string):
+    parts, encoding_flag, msg_type_flag = smpplib.gsm.make_parts(string)
+
+    print 'Sending SMS "%s" to %s' % (string, dest)
+    for part in parts:
+        pdu = client.send_message(
+            source_addr_ton=smpplib.consts.SMPP_TON_INTL,
+            source_addr_npi=smpplib.consts.SMPP_NPI_ISDN,
+            source_addr='3802',
+            dest_addr_ton=smpplib.consts.SMPP_TON_INTL,
+            dest_addr_npi=smpplib.consts.SMPP_NPI_ISDN,
+            destination_addr=dest,
+            short_message=part,
+            data_coding=encoding_flag,
+            #esm_class=msg_type_flag,
+            esm_class=smpplib.consts.SMPP_MSGMODE_FORWARD,
+            registered_delivery=False,
+    )
+    print(pdu.sequence)
+
+
+client = smpplib.client.Client('127.0.0.1', 2775)
+
+# Print when obtain message_id
+client.set_message_sent_handler(
+    lambda pdu: sys.stdout.write('sent {} {}\n'.format(pdu.sequence, pdu.message_id)))
+client.set_message_received_handler(
+    lambda pdu: sys.stdout.write('delivered {}\n'.format(pdu.receipted_message_id)))
+
+client.connect()
+client.bind_transceiver(system_id='test', password='test')
+
+destinations = ('3802', '7839', '3807', '3811', '3806', '3805', '3804', '3809', '3812', '3815', '3814', '3803', '3813')
+
+for dest in destinations:
+    send_message(dest, 'Mahlzeit')
+
+client.listen()