sip conferencing reloaded

Saúl Ibarra Corretgé

AG Projects SIP Conferencing ReloadedThe SIP Infrastructure Experts

AG Projects

● SIP infrastructure for providers● SIPThor: horizontal scalability without user limit● Software projects:

● Blink● SIPSIMPLE SDK● SylkServer● MediaProxy● OpenXCAP● MSRPRelay


Current state of the art


Conferencing today

● Usually mere RTP mixers● Conference calls need a context● Lack of multiplexed information

● Different media types● Session information● Participants information● Shared resources

● There is sometimes a nice website with information


SylkServer


SylkServer

● Open Source SIP application server● Conferencing

● HD audio● Chat● File transfer● Screen sharing

http://sylkserver.com

http://sylkserver.com/


SIP Chatserver

● Chat server using MSRP

● Ad-hoc rooms● Join using SIP

2009 2011 20122010


● SIP chatserver no longer worked with our latest APIs

● Needed a rewrite

2009 2011 20122010


Less than a week later...


SIP Chatserver Reloaded

● HD audio● Multiparty chat● Conference event

package

2009 2011 20122010


SylkServer 1.0.0

● HD audio conferencing● Multiparty chat● Participants information

2009 2011 20122010


Blink 0.24.0 + SylkServer 1.1.0● HD audio

conferencing● Multiparty chat● Participants

information● Add / remove

participants

2009 2011 20122010


Blink Pro 1.1.0 + SylkServer 1.2.0● HD audio



participants● File transfers (push

and pull)

2009 2011 20122010


Blink Pro 1.6.0 + SylkServer 1.3.0● HD audio



participants● File transfers (push

and pull)● Screensharing

2009 2011 20122010


How does it actually work?


MSRP

● Message Session Relay Protocol● Real IM (session based) for SIP● RFC 3428 (SIP MESSAGE) is not real IM● Very simple, just a couple of RFCs (4975 and 4976)● TLS is mandatory


MSRP

● MSRP allows us to negotiate a TCP connection between 2 SIP endpoints● Instant Messaging● File transfer (RFC 5547)● Screen sharing– VNC over MSRP (expired draft)– Stream images


MSRP

v=0

o=- 3519532764 3519532764 IN IP4 192.168.1.43

s=Blink Pro 1.1.2 (MacOSX)

c=IN IP4 192.168.1.43

t=0 0

m=message 2855 TCP/TLS/MSRP *

a=path:msrps://192.168.1.43:2855/fd5a5fbfe517e6c2ed76;tcp

a=accept-types:message/cpim text/* application/im-iscomposing+xml

a=accept-wrapped-types:*

a=setup:active


MSRP

v=0

o=- 3519533090 3519533090 IN IP4 192.168.1.43

s=Blink Pro 1.1.2 (MacOSX)

c=IN IP4 192.168.1.43

t=0 0

m=message 2855 TCP/TLS/MSRP *

a=path:msrps://192.168.1.43:2855/15be969db481aaa26f35;tcp

a=sendonly

a=accept-types:*

a=accept-wrapped-types:*

a=setup:active

a=file-selector:name:"clever_algorithms.pdf" type:application/pdf size:3133774 hash:sha1:87:F7:A7:5A:F5:48:0F:8A:DD:3F:D8:49:F0:86:51:93:A2:9B:89:19


A SIP conference server


Contact: <sip:[email protected]:5060>;isfocus


Conference event package

SUBSCRIBE sip:[email protected] SIP/2.0

Via: SIP/2.0/UDP 192.168.1.43:60530;rport;branch=z9hG4bKPjEgakb...

Max-Forwards: 70

From: "Saúl" <sip:[email protected]>;tag=I3OcER0qmkv...

To: <sip:[email protected]>

Contact: <sip:[email protected]:60530>

Call-ID: cv8.LQxG4qjcDZSxOZKoOhQr0OF7lz-Z

CSeq: 26852 SUBSCRIBE

Event: conference

Expires: 3600

Accept: application/conference-info+xml

Allow-Events: conference, message-summary, presence, presence.winfo, xcap-diff, refer

User-Agent: Blink Pro 1.1.2 (MacOSX)

Content-Length: 0


RFC4575 payload

<conference-description> <display-text>Ad-hoc conference</display-text> <free-text>Hosted by SylkServer-1.2.1</free-text></conference-description><host-info> <web-page>http://sylkserver.com</web-page></host-info><conference-state> <user-count>1</user-count> <active>true</active></conference-state>

http://sylkserver.com/


RFC4575 payload

<users state="full"> <user entity="sip:[email protected]" state="full"> <display-text>Saúl</display-text> <endpoint entity="sip:[email protected]:60530" state="full"> <display-text>Saúl</display-text> <status>connected</status> <joining-info><when>2011-07-13T23:39:07+02:00</when></joining-info> <media id="152141036"><type>message</type></media> </endpoint> </user></users>


RFC4575 payload

<agp-conf:resources>

<agp-conf:files>

<agp-conf:file name="fry.png" hash="sha1:E1:FA:5C:C2:0A:95:DC:3C:C0:7E:AD:F6:25:50:BB:62:D9:F5:B8:3B" size="177533" sender="Saul <sip:[email protected]>" status="OK"/>

</agp-conf:files>

</agp-conf:resources>


Adding / removing participants

REFER sip:[email protected] SIP/2.0

Via: SIP/2.0/UDP 192.168.99.36:65017;rport;branch=z9hG4bKPjjao...

Max-Forwards: 70

From: "Saúl" <sip:[email protected]>;tag=7HXkWbL...

To: <sip:[email protected]>

Contact: <sip:[email protected]:65017>

Call-ID: oiXv9JpNLp9f8GbRLDYw6dVrEnhU7On0

CSeq: 15438 REFER

Event: refer

Accept: message/sipfrag;version=2.0

Allow-Events: conference, message-summary, presence, presence.winfo, xcap-diff, refer

Refer-To: <[email protected]>;method=INVITE

Referred-By: sip:[email protected]

User-Agent: Blink Pro 1.3.0 (MacOSX)

Content-Length: 0


What about Asterisk?


Basic conference info with Asterisk (idea)


BYE

1. Everything should be a building block

2. Our customers need help

3. Use Open Standards

4. “Let's build it before we're too old to enjoy it”

Carl G. Fisher

5. “Skate to where the puck is going to be, not

where it has been”Wayne Gretzky


BYE sip:audience@itexpo SIP/2.0Via: SIP/2.0/UDP 192.168.99.23:49919;rport;branch=z9hG4bKPjDb30Dx0sH-ozn9QB.cCCboyU.atR97aMMax-Forwards: 70From: "saghul" <sip:[email protected]>;tag=UCpGKVZbQQx7BUKYtiuPEX668oa9jaU7To: <sip:audience@itexpo>;tag=as59aef35cCall-ID: DEWDfu63OACwYeQk7MrhmRhRq.1cqqisCSeq: 10633 BYERoute: <sip:81.23.228.129;lr;ftag=UCpGKVZbQQx7BUKYtiuPEX668oa9jaU7;did=641.a8a9c553>User-Agent: blink-0.20.2Content-Length: 0

[email protected]

sip:[email protected]

@saghul


References

● MSRP protocol (RFC4575, RFC4576)● MSRP file transfer (RFC5547)● MSRP switch (draft-ietf-simple-chat)● Conference event package (RFC4575)● A framework for conferencing with SIP (RFC4353)● Conferencing for User Agents (RFC4579)

sip conferencing reloaded

Technology

sip message

sip rfc

user limit software

macosx c

sal ibarra corretg

providers sipthor

horizontal scalability

withour latest apis