top 5 challenges to add web calls to truphone voip platform

Top 5 Challenges to Add Web Calls to Truphone VoIP

Platform

Giacomo VaccaSenior Network Applications Developer

© 2014 Truphone Limited. All Rights Reserved. 05 August 2014

labs.truphone.com

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© 2014 Truphone Limited. All Rights Reserved. 05 August 2014 3

WebRTC is not for VoIP devs


The “Traditional Architecture”


• Follow standards

• Use Open Source products

• Think scalability since the beginning

• Don’t compromise on security

• Change often, keep technical debt low

• Deploy automatically

5

Design Principles


• JS client (JsSIP-based)

• WebSockets

• Authentication

• Media relay for p2p sessions

• FreeSWITCH out of the media path

• Web/VoIP/PSTN interaction

–Support for DTLS

6

Changes Required


Websocket support

7

Challenge 1


Adding WebSocket support…


… with Kamailio


Kamailio websocket module

loadmodule "websocket.so"

…

event_route[xhttp:request] {

set_reply_close();

set_reply_no_connect();

…

if ($hdr(Upgrade)=~"websocket" && $hdr(Connection)=~"Upgrade"

&& $rm=~"GET") {

if (ws_handle_handshake()) {

exit;

}

}

}

10

WebSockets support


v=0

o=- 2700277954018656518 2 IN IP4 127.0.0.1

s=-

t=0 0

a=group:BUNDLE audio video

a=msid-semantic: WMS e8hFvtt1SQ9FiqpbYbOhN19wvpp21flszxZ4

m=audio 63529 RTP/SAVPF 111 103 104 0 8 106 105 13 126

c=IN IP4 162.243.255.49

a=rtpmap:111 opus/48000/2

a=fmtp:111 minptime=10

a=rtpmap:103 ISAC/16000

a=rtpmap:104 ISAC/32000

a=rtpmap:0 PCMU/8000

a=rtpmap:8 PCMA/8000

11

Gigantic SDP 1/10


a=rtpmap:106 CN/32000

a=rtpmap:105 CN/16000

a=rtpmap:13 CN/8000

a=rtpmap:126 telephone-event/8000

a=rtcp:63529 IN IP4 162.243.255.49

a=candidate:1867667642 1 udp 2122260223 192.168.254.1 58603 typ

host generation 0


host generation 0


host generation 0


host generation 0

12

Gigantic SDP 2/10


a=candidate:882550992 1 udp 2122129151 10.2.129.202 58605 typ host

generation 0


generation 0

a=candidate:567387210 1 tcp 1518280447 192.168.254.1 0 typ host

generation 0


generation 0


generation 0


generation 0


generation 0

13

Gigantic SDP 3/10



generation 0

a=candidate:3427568147 1 udp 41754367 162.243.255.49 63529 typ relay

raddr 195.110.37.225 rport 48569 generation 0



a=ice-ufrag:JuWsZDrjSjaP91bz

a=ice-pwd:QUc3SJ/aJe+FLa658U5y2qJp

a=ice-options:google-ice

a=fingerprint:sha-256

C0:42:EE:16:BF:BD:87:76:A4:0F:F6:A9:48:C8:BA:45:2E:0E:AD:1F:41:AA:

C3:3C:99:45:CA:FE:50:9D:E4:32

a=setup:actpass

a=mid:audio

14

Gigantic SDP 4/10


a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level

a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time

a=rtcp-mux

a=maxptime:60

a=ssrc:2566549015 cname:TdImtoO7ee/QmnJN

a=ssrc:2566549015 msid:e8hFvtt1SQ9FiqpbYbOhN19wvpp21flszxZ4

d7516c7a-7f81-4598-a2e6-aa71b7ceb8db

a=ssrc:2566549015 mslabel:e8hFvtt1SQ9FiqpbYbOhN19wvpp21flszxZ4

a=ssrc:2566549015 label:d7516c7a-7f81-4598-a2e6-aa71b7ceb8db

m=video 63529 RTP/SAVPF 100 116 117 96

c=IN IP4 162.243.255.49

a=rtpmap:100 VP8/90000

a=rtpmap:116 red/90000

a=rtpmap:117 ulpfec/90000

15

Gigantic SDP 5/10


a=rtpmap:96 rtx/90000

a=fmtp:96 apt=100

a=rtcp:63529 IN IP4 162.243.255.49


host generation 0


host generation 0


host generation 0


host generation 0


generation 0


generation 0

16

Gigantic SDP 6/10



generation 0


generation 0


generation 0


generation 0


generation 0


generation 0





Gigantic SDP 7/10


a=ice-ufrag:JuWsZDrjSjaP91bz

a=ice-pwd:QUc3SJ/aJe+FLa658U5y2qJp

a=ice-options:google-ice

a=fingerprint:sha-256

C0:42:EE:16:BF:BD:87:76:A4:0F:F6:A9:48:C8:BA:45:2E:0E:AD:1F:41:AA:

C3:3C:99:45:CA:FE:50:9D:E4:32

a=setup:actpass

a=mid:video

a=extmap:2 urn:ietf:params:rtp-hdrext:toffset

a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time

a=rtcp-mux

a=rtcp-fb:100 ccm fir

a=rtcp-fb:100 nack

a=rtcp-fb:100 nack pli

a=rtcp-fb:100 goog-remb18

Gigantic SDP 8/10


a=ssrc-group:FID 1964375756 3405612694



fb4cdb67-4167-4f63-a934-fa49977f955a


a=ssrc:1964375756 label:fb4cdb67-4167-4f63-a934-fa49977f955a



fb4cdb67-4167-4f63-a934-fa49977f955a


a=ssrc:3405612694 label:fb4cdb67-4167-4f63-a934-fa49977f955a

19

Gigantic SDP 9/10


Gigantic SDP 10/10

Increase tcp_rd_buf_size!


WebRTC/VoIP and WebRTC/PSTN

21

Challenge 2


• FreeSWITCH to the rescue– session:execute("export", "media_webrtc=true")

– session:setVariable("bypass_media", "true")

• Certs for DTLS– /etc/freeswitch/tls/dtls-srtp.crt

• Transcoding (mod_opus)– <load module="mod_opus"/>

22

WebRTC/VoIP (and PSTN)


WebRTC/VoIP - WebRTC/PSTN


Authentication

24

Challenge 3


Ephemeral Authentication


Kamailio auth_ephemeral module

loadmodule "auth.so“

loadmodule "auth_ephemeral.so“

…

modparam("auth_ephemeral", "secret", AUTH_EPHEMERAL_SECRET)

…

if (!autheph_proxy("$fd")) {

auth_challenge("$fd", "0");

exit;

}

26

Ephemeral Authentication


Media relay for p2p

27

Challenge 4


• rfc-5766-turn-server

–Open Source

–Easy to set up (e.g. Puppet)

–Ephemeral auth. applies here too!

• JsSIP configuration easy:– turn_servers: { urls: [“turn:myturn.com”], username: “u”, credentials: “c”}

28

Media relay (TURN + STUN)


Media relay (TURN + STUN)


Testing

30

Challenge 5


• From sipp & PJSUA to… Selenium?

• Chrome and FF change

–A lot

–Often

• JsSIP master vs develop (re-INVITEs)

• FreeSWITCH 1.5 or 1.4?

31

5. Testing


Dealing with Web Developers

32

Bonus challenge


• Different tools/processes

• Bleeding edge libs/apps

• Automating deployment of non-stock apps?

• Don’t care about signalling/media

33

Web Development


findable.io


• Big shift to web technologies

• No need to revolutionize your VoIP platform

• SIP can do the job, but…

–verto endpoint for FreeSWITCH?

• (Automated) Testing is hard

• chrome://webrtc-internals is cool

35

Wrapping up


Q&A

Giacomo Vacca - @giavac

[email protected]

https://labs.truphone.com/about/

36

mailto:[email protected]

https://labs.truphone.com/about/

top 5 challenges to add web calls to truphone voip platform

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