Speech at ClueCon about Seven's FreeSWITCH experience

1. Experience on FreeSWITCH
Seven Du

2. About me
• Seven Du - seven - 7 - Du Jinfang -
• 7+ years of PSTN, from 2001
• 3+ years of FS and Erlang - from 2008
• Created www.freeswitch.org.cn at 2009
• about.me/dujinfang dujinfang@gmail.com

3. Agenda
• Work at the past
• Talking to the web
• Manage on web - the GUI
• SIP tracing
• FreeSWITCH in China

4. Past
• China Telecom/Netcom, PSTN
• Idapted, EQEnglish
• Student (CN) ----- FS ---- Teacher (US)
• Problem: SIP/RTP traffic cross the ocean
• sofia, skypopen, dingaling

5. fsm_ivr
• Written in Erlang using gen_fsm
• Like plivo but simpler
• Since it’s simple we don’t have a client
library like plivo, plain text only

6. http://localhost/ivr.txt
answer
play welcome.wav
read please-input-a-number.wav
next ivr.php

7. read please-input-a-number.wav
next ivr.php
http://localhost/ivr.php
set bridge_url=http://.....
play calling.wav
<?php $dtmf = $_GET[‘dtmf’];
echo “say_digits $dtmf”;
echo “bridge $dtmf”;
echo “next /blah......”; ?>

8. Simplified & Enenced API
• play file.wav
• play file1.wav file2.wav file3.wav
• play file_string://file1.wav!file2.wav!file3.wav
• say_digits 1234
• say_digits 1234 zh
• say_number 1234.56

9. Well configured default
values to make API as
simple as it can be
• read file.wav
• read file.wav max
• read file min max
• read file min max term
• read file min max term timeout

10. Callbacks
• set bridge_url=/call_bridged
• set hangup_url=/call_hangup
Macros
• ola://BEEP
• read file_string://record-after-beep.wav!ola://BEEP

11. Compatibal with FS APIs
It has to be !

12. Outbound (REST)
curl
-d "number=1001&ivr_dest=7000
&callback=http://localhost:3000/blah"
localhost:8765/api/make_call
• {"code":"200", "job_id":"4f7fdca6-9a9f-11e0-b28e-
a342d0897a44"}
• {"code":"702", "error_text":"no trunk available"}

13. Real world use
• calling card
• crbt - Color Ring Back Tone
• universal number
• universal messaging
• (not yet opensourced)

14. Managing on web - the GUI
• Why re-invent the wheel?

15. We use ...
• mod_xml_curl
• websocket (via socket.IO)
• Ruby/Rails for GUI
• Erlang as a middleware
• RabbitMQ for messaging

16. • ajax pooling

17. • ajax pooling
• websocket/socket.IO

18. • Connected websocket
• Agent 1000 registered and Ready!

19. • H/h = Hear/UnHear S/s = Speak/UnSpeak

20. SIP trace (Tracking 2+ legs)
• simply TPORT_LOG (Homer ?)
• custom header x_interaction

21. FreeSWITCH in China
• 103 members in FreeSWITCH-CN google
groups
• 175 members on QQ
•-
• China has1,339,724,852 People in 2010 not
including Hongkong, Macao and Taiwan

22. SIP/VoIP in China
• Backbone/Core switching in telecom carries already
IPlized
• Only legal (Experimental) in certain cities
• Cisco/Avaya for commercial enterprise internal use
• Asterisk based products mainly selling cards -
openvox Digium Samgoma etc.
• FS Community members from small(like me) and
big tech companies (Huawei/Alibaba...), and they
from assurances, petro, government even military

23. FS Commercial support
in China
x-y-t.com

24. Thanks
• about.me/dujinfang
• dujinfang@gmail.com