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Applications » History » Revision 2

Revision 1 (Tijmen de Mes, 04/05/2012 06:01 PM) → Revision 2/11 (Tijmen de Mes, 04/05/2012 06:03 PM)

h1. Built-in Applications 

 h2. Multiparty Conference 

 SylkServer allows SIP end-points to create ad-hoc conference rooms by sending INVITE with SDP content to a random username at the hostname or domain where the server runs. Other participants can then join by sending an INVITE to the same SIP URI used to create the room. 

 h2. Supported Media 

 The INVITE and subsequent re-INVITE methods may contain one or more media types supported by the server. Each conference room mixed audio, instant messages and uploded files are dispatched to all participants. 

 +Audio+ The INVITE must propose a session with RTP (m=audio in SDP). Re-INVITE to add or remove audio to existing session is supported. G722, speex (both in wideband) and G711 codecs are supported. 
 <pre> 
 Content-Type: application/sdp 
 Content-Length: 233 

 v=0 
 o=- 3526098545 3526098547 IN IP4 81.23.228.139 
 s=SylkServer-1.2.3 
 t=0 0 
 c=IN IP4 81.23.228.139 
 m=audio 55324 RTP/AVP 9 101 
 c=IN IP4 85.17.186.7 
 a=rtcp:55325 
 a=rtpmap:9 G722/8000 
 a=rtpmap:101 telephone-event/8000 
 a=fmtp:101 0-15 
 a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:1nDEh/WrJ57RBaHwhBG4+RAwzV9k/HxZhg1wClnx 
 a=sendrecv 
 </pre> 

 +Instant Messaging.+ The INVITE must propose a session with MSRP chat over TLS (m=message and a=path:msrps in the SDP). Re-INVITE to add or remove chat to existing session is supported. Private messaging extension between participants is also supported. 

 <pre> 
 Content-Type: application/sdp 
 Content-Length: 213 

 v=0 
 o=- 3526098545 3526098547 IN IP4 81.23.228.139 
 s=SylkServer-1.2.3 
 t=0 0 
 m=message 60167 TCP/TLS/MSRP * 
 c=IN IP4 81.23.228.139 
 a=path:msrps://81.23.228.139:60167/f8d1058769bebacacf62;tcp 
 a=accept-types:message/cpim 
 a=accept-wrapped-types:* 
 a=setup:passive 
 a=chatroom:private-messages 
 </pre> 

 +File Transfer+. The INVITE must propose a session with MSRP file transfer media description. Re-INVITE to add a file to existing session is supported. Participants that join later can request the previously uploaded files by using MSRP pull method. 

 <pre> 
 Content-Type: application/sdp 
 Content-Length:     407 

 v=0 
 o=- 3526099467 3526099468 IN IP4 81.23.228.139 
 s=SylkServer-1.2.3 
 c=IN IP4 81.23.228.139 
 t=0 0 
 m=message 39084 TCP/TLS/MSRP * 
 a=path:msrps://81.23.228.139:39084/a06af01b810519fb6090;tcp 
 a=recvonly 
 a=accept-types:* 
 a=accept-wrapped-types:* 
 a=setup:passive 
 a=file-selector:name:"Blink.pdf" type:application/pdf size:151036 hash:sha1:49:AD:49:... 
 </pre> 

 +Screen Sharing.+ This functionality is implemented as com.ag-projects.screen-sharing extension to the chatroom functionality. 

 <pre> 
 Content-Type: application/sdp 
 ... 

 m=message 40278 TCP/TLS/MSRP * 
 a=path:msrps://81.23.228.149:40278/2aa5bbb5d37731ef85c0;tcp 
 a=accept-types:message/cpim 
 a=accept-wrapped-types:* 
 a=setup:passive 
 a=chatroom:private-messages com.ag-projects.screen-sharing 
 </pre> 

 If the end-point detects and supports this private extension, it can share the screen by pushing at regular intervals a jpeg image with the desktop content over the MSRP chat stream. The image must be encapsulated in a CPIM envelope using content type application/blink-screensharing. Blink SIP client implements this extension. 
 <pre> 
 MSRP eea58af6af1b788 SEND 
 To-Path: msrps://81.23.228.149:41652/a65812de6f6a0725ee1a;tcp 
 From-Path: msrps://192.168.1.6:2855/e7028b404511ed77d6a2;tcp 
 Message-ID: 641f9960ded0638d 
 Byte-Range: 1-*/245347 
 Success-Report: yes 
 Failure-Report: yes 
 Content-Type: message/cpim 

 From: Adrian Georgescu <sip:31208005169@ag-projects.com> 
 To: <sip:nnauyj@conference.sip2sip.info> 
 DateTime: 2011-12-22T09:12:04+01:00 

 MIME-Version: 1.0 
 Content-Type: application/blink-screensharing 
 ÿØÿàJFIF ............. 
 </pre> 
 The server then makes the screenshot available at a HTTP URL and publishes this URL to all participants using the conference information notification using <agp-conf:screen_image_url> extension. Participants can see the screen using a specialized client or a regular web browser. 

 h2. Conference Information 

 To obtain the conference information send a SUBSCRIBE request to the room URI for Event conference "RFC 4575":http://tools.ietf.org/html/rfc4579. RFC 4575. The NOTIFY contains detailed information with the list of participants, their connected endpoints, media type and stream status and information about uploaded files. 
 <pre> 
 

 Content-Type: application/conference-info+xml 
 Content-Length:     975 

 <?xml version='1.0' encoding='UTF-8'?> 
 <conference-info xmlns:agp-conf="urn:ag-projects:xml:ns:conference-info"  
     xmlns="urn:ietf:params:xml:ns:conference-info"  
     entity="sip:agp@conference.sip2sip.info" state="full"> 
     <conference-description> 
         <display-text>Ad-hoc conference</display-text> 
         <free-text>Hosted by SylkServer-1.2.3</free-text> 
         <agp-conf:resources> 
             <agp-conf:files> 
                 <agp-conf:file name="Blink.pdf" hash="sha1:49:AD:49:...." 
                 size="151036" sender="AG <sip:31208005169@ag-projects.com>" status="OK"/> 
             </agp-conf:files> 
         </agp-conf:resources> 
     </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> 
     <users state="full"> 
         <user entity="sip:31208005169@ag-projects.com" state="full"> 
             <display-text>Adrian Georgescu</display-text> 
             <agp-conf:screen_image_url>https://81.23.228.146/?image=WfPeNYF195.jpg</agp-conf:screen_image_url> 
             <endpoint entity="sip:pbvusniw@95.97.50.27:54325" state="full"> 
                 <display-text>Adrian Georgescu</display-text> 
                 <status>connected</status> 
                     <joining-info> 
                         <when>2011-09-27T09:49:05+02:00</when> 
                     </joining-info> 
                 <media id="170092876"><type>message</type></media> 
                 <media id="2977223756"><type>audio</type></media> 
             </endpoint> 
         </user> 
     </users> 
 </conference-info> 
 </pre> 
 h2. Participant Management 

 To add and remove participants, SylkServer supports INVITE and REFER methods as defined in "RFC4579 RFC4579 (Conferencing for User Agents)":http://tools.ietf.org/html/rfc4579#section-5 . Agents). One can remove or add participants by sending a REFER method to the conference URI. 

 <pre> 
 REFER sip:agp@conference.sip2sip.info SIP/2.0 
 Via: SIP/2.0/UDP 10.211.55.2:54325;rport;branch=z9hG4bKPj7PFxy8RLtr20jfVyUx2eis1H7.1aY7Np 
 Max-Forwards: 70 
 From: "Adrian Georgescu" <sip:31208005169@ag-projects.com>;tag=ZtGlJFOgGvwWQEMae6uTpuhT1aREkQeR 
 To: <sip:agp@conference.sip2sip.info> 
 Contact: <sip:pbvusniw@192.168.1.6:54325> 
 Call-ID: rYp1GQbSQ8kFrC1xccpfA5t9GXaR5qwt 
 CSeq: 6839 REFER 
 Event: refer 
 Accept: message/sipfrag;version=2.0 
 Allow-Events: conference, message-summary, presence, presence.winfo, xcap-diff, refer 
 Refer-To: <3333@sip2sip.info>;method=INVITE 
 Referred-By: sip:31208005169@ag-projects.com 
 User-Agent: Blink Pro 1.3.1 (MacOSX) 
 Content-Length:    0 
 </pre>