Wideband Audio Conferencing with Asterisk

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Wideband Audio Conferencing with Asterisk

  1. 1. AG Projects ICE: the ultimate way of beating NAT in SIP The SIP Infrastructure Experts AstriCon 2010 Wideband Audio Conferencing with Asterisk Saúl Ibarra Corretgé | AG Projects Because G711 is not enough
  2. 2. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Index ● What is Wideband voice? ● Should I use Wideband anyway? ● Asterisk wideband capabilities ● Conference calls with Asterisk ● Testing and results
  3. 3. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 What is Wideband voice? ● Higher quality voice ● Higher detailed voice ● Richer sound Nothing new! G722 is from 1988!
  4. 4. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 What is Wideband voice? (II) ● Human voice ranges from 30 to 18000 Hz ● The more frequencies we transmit the richer the voice is
  5. 5. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 What is Wideband voice? (III) ● Nyquist sampling theorem ● If we want to transmit X amount of frequencies they need to be sampled at 2X sample rate ● G711 ● ~50 – 4000 Hz -> 8000 Hz sample rate ● G722 ● ~0 – 7000 Hz -> 16000 Hz sample rate
  6. 6. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 What is Wideband voice? (IV) How can G711 and G722 use same bitrate (64 kbps) then? ● G711 ● Uses PCM. 8 bits per sample * 8000 samples = 64 kbps ● G722 ● Uses SB-ADPCM – 48 kbps for the lower band – 16 kbps for the higher band
  7. 7. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 What is Wideband voice? (V)
  8. 8. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Should I use Wideband anyway? Short answer: yes. Long(er) answer: yes, of course. ● “Cleaner” sound ● Easier way to identify voices ● Clearer diference between close sounds: “sailing” vs “failing”, etc. ● Just don't say “what?” ever again. 25% of calls at SIP2SIP.info use wideband Only 2% did use wideband same period last year
  9. 9. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Asterisk codec capabilities Narrowband codecs ● G711 ● GSM ● G729 ● iLBC ● G723.1 ● G726 ● ... Wideband codecs ● G722 ● G722.1 (Siren 7 and Siren 14) ● Speex 16 KHz (new in 1.8!) ● G719 passthrough (new in 1.8!)
  10. 10. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Conferencing Multiple callers involved in a single call
  11. 11. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Conferencing (II) ● Client side ● Server side ● Hosted service
  12. 12. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Asterisk conferencing capabilities Asterisk supports several channel independent applications for conferencing: ● MeetMe ● It's been around since forever ● Mixing is done in DAHDI really ● No wideband support (mixing is done in DAHDI at 8 Khz)
  13. 13. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Asterisk conferencing capabilities (II) ● ConfBridge ● New as of Asterisk 1.6.2 ● Uses “new” Brdging API ● No DAHDI needed ● Wideband capable! ● Can do mixing at 16 Khz or 8 Khz, but not both ● Not as many options as MeetMe... yet!
  14. 14. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Asterisk conferencing capabilities (III) ● AppKonference ● Third party application ● Fork of AppConference, around since Asterisk 1.0.x ● No DAHDI required ● Wideband capable! ● Video capable! ● Not working with Asterisk 1.8 yet
  15. 15. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 A note on timing sources ● Full explanation on doc/timing.txt ● Asterisk supports several sources which can be used to provide internal timing ● res_timing_timerfd – Only available on Linux systems with Kernel >= 2.6.25 & glibc >= 2.8 – Very reliable source of timing ● res_timing_kqueue – Only available on BSD systems (yes, also works on the Mac) ● res_timing_dahdi – Uses DAHDI to provide timing ● res_timing_pthread – Uses the pthread library to provide timing – Least efective, but more portable
  16. 16. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 ConfBridge ● No confguration fle ● Smart bridging: 2 party and multiparty mixing ● Be careful, you can't mix diferent sample rates ● Inbound codec can't be forced ● Not as complete as MeetMe... ● ... I'm sure patches would be welcome :-) exten => _*7XXXX,1,NoOp(Entering conference ${EXTEN:4}) same => n,Answer same => n,ConfBridge(${EXTEN:4},M)
  17. 17. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 AppKonference ● No confguration fle ● Inbound codec can't be forced ● Minimize encoding/decoding ● One speaker: frames sent directly to each participant. Frames transcoded once per codec type ● Two speakers: each speaker gets the other speakers frames. The two speakers frames are then mixed and transcoded once per codec type exten => _*7XXXX,1,NoOp(Entering conference ${EXTEN:4}) same => n,Answer same => n,Konference(${EXTEN:4},H)
  18. 18. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Testing ● See how diferent options perform in terms of CPU usage ● AppKonference ● ConfBridge (with TimerFD timing) ● ConfBridge (with Pthreads timing) ● Test scenarios (always 50 users) ● 1 speaker ● 2 speakers ● Everyone speaking, madness!
  19. 19. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Tools ● pcapsipdump: capture SIP + RTP in PCAP format discarding everything else ● Wireshark: edit captured PCAP ● SIPp: SIP + RTP trafc generation ● sysstat: system stats generation ● OpenOfce: graphics. It sucks, btw. ● Human hear ● Hardware ● Code2Duo desktop computer with 8GB of DDR3 RAM ● Gigabit Ethernet
  20. 20. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Tools: Asterisk versions ● ConfBridge tests ● Asterisk SVN branch 1.8 r292230 ● AppKonference tests ● Asterisk 1.6.2.14-rc1
  21. 21. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Results: 1 Speaker 1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960 0 5 10 15 20 25 30 35 40 45 Single Speaker 1 Speaker (AppKonference) 1 Speaker (ConfBridge + TimerFD) 1 Speaker (ConfBridge + Pthreads)
  22. 22. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Results: 2 Speakers 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 0 10 20 30 40 50 60 70 2 Speakers 2 Speakers (ConfBridge + Pthreads) 2 Speakers (ConfBridge + TimerFD) 2 Speakers (AppKonference)
  23. 23. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Results: 50 Speakers! 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 0 10 20 30 40 50 60 70 80 50 Speakers 50 Speakers (ConfBridge + Pthreads) 50 Speakers (ConfBridge + TimerFD) 50 Speakers (AppKonference)
  24. 24. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Results analysis ● AppKonference had more audio cuts (according to Human Hear TM) ● Short audio-loss when lots of calls were starting (ConfBridge) ● Overall TimerFD performed better than Pthread ● AppKonference was tested on a diferent release version ● With 50 speakers AppKonference produces no audio at all ● ConfBridge doesn't have as many features as good old MeetMe
  25. 25. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Recap ● Wideband can make our conference calls more understandable ● With G722 we use same bandwidth as G711 ● Asterisk provides all the necesary tools for a nice and wideband conference call experience ● ConfBridge looks like the way to go ● All hardware devices involved need to support wideband
  26. 26. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Spam! ● Join the VoIP Users Conference! ● Every friday at 12:00 EDT ● Highly skilled speakers talking about VoIP ● Anyone can join the conference! ● In G722, of course! http://vuc.me
  27. 27. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Questions?
  28. 28. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 BYE BYE sip:audience@astricon.net SIP/2.0 Via: SIP/2.0/UDP 192.168.99.23:49919;rport;branch=z9hG4bKPjDb30Dx0sH-ozn9QB.cCCboyU.atR97aM Max-Forwards: 70 From: "saghul" <sip:saul@ag-projects.com>;tag=UCpGKVZbQQx7BUKYtiuPEX668oa9jaU7 To: <sip:audience@astricon.net>;tag=as59aef35c Call-ID: DEWDfu63OACwYeQk7MrhmRhRq.1cqqis CSeq: 10633 BYE Route: <sip:81.23.228.129;lr;ftag=UCpGKVZbQQx7BUKYtiuPEX668oa9jaU7;did=641.a8a9c553> User-Agent: blink-0.20.2 Content-Length: 0 saul@ag-projects.com sip:saul@ag-projects.com @saghul
  29. 29. AG Projects Wideband Audio Conferencing with Asterisk The SIP Infrastructure Experts AstriCon 2010 Images http://www.fickr.com/photos/kigs/4991332361/sizes/l/in/photost ream/ http://www.cisco.com/en/US/prod/collateral/voicesw/ps6788/pho nes/ps379/ps8537/prod_white_paper0900aecd806fa57a.html http://www.fickr.com/photos/timdorr/2737609108/sizes/z/in/pho tostream/ http://www.trennum.net/hullabaloo/

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