王謙志

SIP Introduction Call Flow Point to Point Flow Transfer Flow Conference Flow Exception How to use JPcap Future Work Reference

Session Initiation Protocol ，透過 IP 封包來完成多媒體通 訊訊號的控制。第一個被提議的標準版本在 RFC 2543 中定義。在 RFC 3261 中對這個協議有更深入的解釋。 由五個元件組成， User Agent 、 Proxy Server 、 Redirect Server 、 Registrar 、 Location Server 。

SIPRMA Proxy Server 、 Redirect Server 、 Registrar 、 Location Server 。

Request nameDescription INVITEIndicates a client is being invited to participate in a call session. ACK Confirms that the client has received a final response to an INVITE request. BYE Terminates a call and can be sent by either the caller or the callee. CANCELCancels any pending request. OPTIONSQueries the capabilities of servers. REGISTER Registers the address listed in the To header field with a SIP server. PRACKProvisional acknowledgement. SUBSCRIBESubscribes for an Event of Notification from the Notifier. NOTIFYNotify the subscriber of a new Event. PUBLISHpublishes an event to the Server. INFO Sends mid-session information that does not modify the session state.

Request name Description REFERAsks recipient to issue SIP request (call transfer.)(RFC 3515) MESSAGETransports instant messages using SIP. UPDATE Modifies the state of a session without changing the state of the dialog.

Response Messages Type Description 1xx Informational Responses ： request received, continuing to process the request. ex. 180 Ringing 、 100 Trying 2xx Successful Responses ： action was successfully received, understood, and accepted. ex. 200 OK 、 202 Accepted 3xx Redirection Responses ： further action needs to be taken in order to complete the request. ex. 302 Moved Temporarily 4xx Request Failure Responses ： the request contains bad syntax or cannot be fulfilled at this server. ex. 404 Not Found 、 407 Proxy Authentication Required 5xx Server Failure Responses ： the server failed to fulfill an apparently valid request. ex. 503 Service Unavailable 6xx Global Failures Responses ： the request cannot be fulfilled at any server. ex. 600 Busy Everywhere

200 OK 可以用來回應如： INVITE 、 REGISTER 、 BYE 等 Request method 。 CSeq ： INVITE Request 200 OK

REFER Request

目前沒有 Conference 這項功能的 Request method 。 由 Conference 發起人送出 INVITE 去邀請另一個人加入。 若是發起人掛斷電話，則 Conference 結束。

Conference call flow

JAVA 本身的 API 並不能抓取到底層的網路數據， JPcap 乃是一種提供 Windows 或 Unix 系統進行捕捉或發送封 包的 Java API 。 JpcapCaptor Jpcap = JpcapCaptor.openDevice() ：設定 網路卡。 JpcapCaptor jpcap.processPacket() ：裝取封包，抓到 後將封包丟至 PacketReceiver 。 到 PacketReceiver 裡的 void receivePacket(Packet packet) function 去處理抓到的封包。

錄製語音檔。 加入資料庫管理。 使用者介面設計。

RFC 3261 RFC 3515 馬兆緯， ” JPANDDR: 網路協定分析、診斷、與資料重 組系統之研製 ” ，國立台北科技大學 資訊工程所， July JPcap col, Session Initiation Protocol - Wikipedia, the free encyclopedia col