SIP

SIP Introduction

SIP Functionality

SIP Architecture

SIP and PSTN Interconnection

SIP Software Modules

SIP Methods

SIP Response

SIP Address Format

Call Set Up Procedure

Registraction

Registraction

Invitation for Proxy

Invitation for Redirect Server

Steps

User Agent to User Agent

User Agent to User Agent

User Agent to User Agent

Call Flow (PSTN-SIP)

Call Flow (PSTN-SIP)

Invite Method

SIP Architecture

SIP Architecture

Untitled Document
SIP Introduction
SIP (Session Initiation Protocol)
 
IETF RFC2543
 
特別為 Internet VoIP 設計的協定
 
應用層(application layer)的協定
優點及特色
 
與IETF協定整合
 
Scalability and simplicity.
 
行動性(Mobility)
 
容易新增特性與服務
 
Text Based Messages, easy to maintain
Wed Mar 16 00:30:02 CST 2011

Untitled Document
SIP Functionality
User location determination of the end system to be used for communication
User capabilities determination of the media and media parameters to be used
User availability determination of the willingness of the called party to engage in communications
Call setup “ringing”, establishment of call parameters at both called and calling party
Call handling including transfer and termination of calls
Wed Mar 16 00:30:03 CST 2011 Untitled Document
SIP Architecture
Wed Mar 16 00:30:05 CST 2011 Untitled Document
SIP and PSTN Interconnection
Wed Mar 16 00:30:06 CST 2011 Untitled Document
SIP Software Modules
 
SIP 網路上有許多 Server 提供 Location, Rediction, 等服務。
Proxy Server
  • 為一個中間程式，可以為server以及client，並為其他client提出需求。
  • 需求可以被直接服務，或是將它們轉化後交給其他的server服務。
    • Location Server 被SIP redirect或proxy伺服器使用， 詢問被呼叫party的可能位置
    Redirect Server
  • 接受SIP的要求，將位置對應到零個或多個新的位置， 並將結果回傳給client
  • 不會主動發出SIP要求
  • 不會接受或結束一個通話
    • Registrar Server
  • 接受註冊要求
  • 提供 authentication
    •  
    在 User 端，有兩個 User Agent 為使用者服務
    User Agent Client 撥電話 (Originating)
    User Agent Server 接電話 (Terminating)
    Wed Mar 16 00:30:07 CST 2011 Untitled Document
    SIP Methods
    INVITE Initiates a call by inviting user to participate in session.
    ACK Confirms that the client has received a final response to an INVITE request.
    BYE Indicates termination of the call.
    CANCEL Cancels a pending request.
    REGISTER Registers the user agent.
    OPTIONS Used to query the capabilities of a server.
    INFO Used to carry out-of-bound information, such as DTMF digits
    Wed Mar 16 00:30:09 CST 2011 Untitled Document
    SIP Response
    1xx Informational Messages.
    2xx Successful Responses.
    3xx Redirection Responses.
    4xx Request Failure Responses.
    5xx Server Failure Responses.
    6xx Global Failures Responses
    Wed Mar 16 00:30:10 CST 2011 Untitled Document
    SIP Address Format
    Address Format 
    user@host
     
    Examples
    sip:user1@ccl.itri.org
    sip:user2@140.119.162.1
    sip:user3@nccu.edu.tw
    Wed Mar 16 00:30:11 CST 2011 Untitled Document
    Call Set Up Procedure
    1. Registering, initiating and locating the user.
    2. Determine the media to use – involves delivering a description of the session that the user is invited to.
    3. Determine the willingness of the called party to communicate – the called party must send a response message to indicate willingness to communicate – accept or reject.
    4. Call setup.
    5. Call modification or handling – example, call transfer (optional).
    6. Call Termination
    Wed Mar 16 00:30:12 CST 2011 Untitled Document
    Registraction
    Wed Mar 16 00:30:13 CST 2011 Untitled Document
    Registraction
    Wed Mar 16 00:30:14 CST 2011 Untitled Document
    Invitation for Proxy
    Wed Mar 16 00:30:16 CST 2011 Untitled Document
    Invitation for Redirect Server
    Wed Mar 16 00:30:17 CST 2011 Untitled Document
    Steps
    Wed Mar 16 00:30:19 CST 2011 Untitled Document
    User Agent to User Agent
    Wed Mar 16 00:30:21 CST 2011 Untitled Document
    User Agent to User Agent
    Wed Mar 16 00:30:23 CST 2011 Untitled Document
    User Agent to User Agent
    Wed Mar 16 00:30:24 CST 2011 Untitled Document
    Call Flow (PSTN-SIP)
    Wed Mar 16 00:30:26 CST 2011 Untitled Document
    Call Flow (PSTN-SIP)
    Wed Mar 16 00:30:27 CST 2011 Untitled Document
    Invite Method
    Wed Mar 16 00:30:28 CST 2011 Untitled Document
    SIP Architecture
    Wed Mar 16 00:30:29 CST 2011 Untitled Document
    SIP Architecture
    Wed Mar 16 00:30:30 CST 2011