97598050 王謙志

SIP Introduction and Packet Analysis

SIP IntroductionCall Flow

Point to Point FlowTransfer FlowConference FlowException

How to use JPcapFuture WorkReference

Outline

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 。

SIP Introduction

SIP Architecture

SIPRMA

程式設計環境：Proxy Server 、Redirect Server 、Registrar 、Location Server 。

Request name Description

INVITE Indicates 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.

CANCEL Cancels any pending request.OPTIONS Queries the capabilities of servers.

REGISTER Registers the address listed in the To header field with a SIP server.

PRACK Provisional acknowledgement.

SUBSCRIBE Subscribes for an Event of Notification from the Notifier.

NOTIFY Notify the subscriber of a new Event.PUBLISH publishes an event to the Server.

INFO Sends mid-session information that does not modify the session state.

Request methods

Request name Description

REFER Asks recipient to issue SIP request (call transfer.)(RFC 3515)

MESSAGE Transports instant messages using SIP.

UPDATE Modifies the state of a session without changing the state of the dialog.

Request methods

Response codesResponse

Messages Type Description

1xxInformational Responses ： request received,

continuing to process the request.ex. 180 Ringing 、 100 Trying

2xxSuccessful Responses ： action was successfully

received, understood, and accepted.ex. 200 OK 、 202 Accepted

3xxRedirection 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

5xxServer Failure Responses ： the server failed to

fulfill an apparently valid request.ex. 503 Service Unavailable

6xxGlobal Failures Responses ： the request cannot be

fulfilled at any server. ex. 600 Busy Everywhere

Point to Point Call

INVITE Request

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

CSeq ：

200 OK Response

INVITE Request

200 OK

BYE Request

Transfer Call

REFER Request

Transfer Call

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

Conference call flow

201 202 203

Exception ： CANCEL Request

CANCEL Request

486 Busy Here Response

486 Busy Here Response

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。

How to use JPcap

錄製語音檔。加入資料庫管理。使用者介面設計。

Future Work

RFC 3261RFC 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 2007http://netresearch.ics.uci.edu/kfujii/jpcap/doc/index.html,

JPcaphttp://

en.wikipedia.org/wiki/Session_Initiation_Protocol, Session Initiation Protocol - Wikipedia, the free encyclopedia

Reference

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