SIP Awesome

• fonoster/fonos open-source alternative to Twilio
  • MIT, Nodejs+Redis
• fonoster/routr
  • MIT, Nodejs+Resit
  • sip proxy, location server, registrar
  • TCP, UDP, TLS, WS, WSS
  • 路由 Intra-Domain, Domain Ingress, Domain Egress, Peer Egress
• http://callflow.sourceforge.net/
  • 生成呼叫流
• https://web.archive.org/web/20120106005622/https://www.iptel.org/~sipsc/
• https://en.wikipedia.org/wiki/List_of_SIP_response_codes
• SIP Proxy
  • Kamailio
  • OpenSIPS
• PBX
  • Asterisk
  • FreeSwitch
• sipcapture
  • homer
    • SIP / VoIP / RTC Packet Capture & Monitoring
  • heplify-server
    • HEP Capture Server

SIP

rfc	title	Obsoleted by
rfc3261	SIP: Session Initiation Protocol
rfc3262	Reliability of Provisional Responses
rfc3265	Event Notification	rfc6665
rfc3581	Symmetric Response Routing
rfc3666	PSTN Call Flows
rfc3959	The Early Session Disposition Type
rfc5373	Requesting Answering Modes
rfc5839	Events for Conditional Event Notification
rfc6228	Response Code for Indication of Terminated Dialog
rfc6337	SIP Usage of the Offer/Answer Model
rfc6665	Event Notification
rfc7118	WebSocket Protocol as a Transport

// options
"100rel": true, // RFC 3262
"199": true, // RFC 6228
answermode: true, // RFC 5373
"early-session": true, // RFC 3959

// status code
199: "Early Dialog Terminated", // draft-ietf-sipcore-199
200: "OK",
202: "Accepted", // RFC 3265
204: "No Notification", // RFC 5839

Session State

                  ___________________________________________________________
                 |  ____________________________________________             |
                 | |            ____________________________    |            |
Session          | |           |                            v   v            v
Constructed -> Initial -> Establishing -> Established -> Terminating -> Terminated
                               |               |___________________________^   ^
                               |_______________________________________________|

Signaling State

	Offer	Answer	RFC	Ini	Est	Early
1.	INVITE Req.	2xx INVITE Resp.	RFC 3261	Y	Y	N
2.	2xx INVITE Resp.	ACK Req.	RFC 3261	Y	Y	N
3.	INVITE Req.	1xx-rel INVITE Resp.	RFC 3262	Y	Y	N
4.	1xx-rel INVITE Resp.	PRACK Req.	RFC 3262	Y	Y	N
5.	PRACK Req.	200 PRACK Resp.	RFC 3262	N	Y	Y
6.	UPDATE Req.	2xx UPDATE Resp.	RFC 3311	N	Y	Y

[Summary of SIP Usage of the Offer/Answer Model]

rfc6337#section-2.2

SDP

• clux/sdp-transform simple parser/writer for the Session Description Protocol