A gentle introduction to sip and cpl january 31 2001
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A Gentle Introduction to SIP and CPL January 31, 2001. Session Initiation Protocol Call Processing Language. Outline. What is SIP and Why is it Important (10 min) SIP Architecture and Protocol (15 min) SIP Call Flow Examples (10 min) The IETF Call Processing Language (15 min)

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A gentle introduction to sip and cpl january 31 2001

A Gentle Introduction toSIP and CPLJanuary 31, 2001

Session Initiation ProtocolCall Processing Language


Outline

Outline

  • What is SIP and Why is it Important (10 min)

  • SIP Architecture and Protocol (15 min)

  • SIP Call Flow Examples (10 min)

  • The IETF Call Processing Language (15 min)

  • SIP Activities (10 min)

  • Discussion


What is sip and why is it important

What is SIP andWhy is it Important

Tom Gray

Strategic Technology


What sip is

What SIP Is

  • SIP is a language and protocol for initiating, modifying and terminating interactive sessions

    • allows discovery of entities so that descriptions of sessions can be delivered

      • is explicitly designed for rendezvous with mobile users

      • is explicitly distributed with local user control

      • enables creation and sharing of information

      • maintains relationships over multiple interactions


What sip is1

What SIP Is

  • compatible with existing telephony features but also designed for new applications enabled by the Internet

    • example of highly personalized call control

      • with location, presence, alerts, notifications ...

  • one of a family of protocols and languages

    • pervasive (DTMF of the Internet)

    • based on SMTP and HTTP

    • set of building blocks to design services

    • lightweight and extensible


  • What sip is not

    What SIP Is Not

    • a telephony protocol

    • a resource reservation protocol

    • a transfer protocol

    • a normative definition of any specific set of features

    • the AIN, Q.sig, H.323…


    A gentle introduction to sip and cpl january 31 2001

    Group

    TRIP Billing

    Group

    TRIP Billing Locate

    Group

    TRIP Billing

    ARS

    User Agent

    Client

    SIP

    User Agent

    User Agent

    SIP

    Server

    Client

    MGCP

    MGCP

    Media Gateway

    Media Gateway

    Media Gateway

    IP, ATM, PSTN…

    Media Gateway

    CPL


    Sip in context

    SIP in Context

    Coordination Space

    SIP

    SIP

    Policy Agents

    External Data Sources

    SIP

    Policies

    Database

    Connection Control


    A gentle introduction to sip and cpl january 31 2001

    Alice

    Location/Presence Server

    ACD Proxy Server

    TRIP

    Carol

    BIGAgent

    BIG

    SIP

    Bob

    SIP

    Available

    English

    Available

    French

    Busy

    French

    Daniel

    Personal Agent

    ACD Example

    SIP

    SIP

    SIP

    Call inFrench…

    Personal Agents


    Sip architecture and protocol

    SIP Architecture and Protocol

    Kathy Baker

    Strategic Technology

    Based on the IETF Draft: ietf-sip-rfc2543bis-02.ps(November 24, 2000)


    Sip user agents

    Client sends a request message

    Server sends back a response message

    CALLER

    CALLEE

    200 OK

    UserAgentServer

    UserAgentServer

    INVITE

    UserAgentClient

    UserAgentClient

    SIP User Agents


    Sip servers

    SIP Servers

    • Proxy

      • Stateless Proxy

        • forgets about SIP request/response once it has been forwarded

      • Stateful Proxy

        • maintains record of SIP transaction

        • e.g. Outbound Proxy (located near client acts as firewall)

    • Redirect Server

      • does not issue SIP requests, only redirect responses

    • Registrar

      • allows user agents to register location information

      • typically co-located with Outbound Proxy


    Sip architecture example

    SIP PATH

    INVITE

    200 OK

    ACK

    ACK

    302

    INVITE

    UserAgentServer

    UserAgentServer

    INVITE

    200 OK

    UserAgentClient

    UserAgentClient

    ACK

    INVITE

    200 OK

    ACK

    MEDIA PATH

    SIP Architecture example

    Stateful Proxy

    CALLER

    CALLEE

    Redirect Server

    Stateless Proxy


    Sip messages

    SIP Messages

    • Can either be Request or Response message

      • Request: From Client to Server

      • Response: From Server to Client

    • Can be passed:

      • from user agent to user agent

      • from SIP network server to user agent or vice versa

      • from SIP network server to SIP network server

    • Each SIP Message contains:

      • Request Line or Status Line

      • Header

      • Message (CPL, SDP, encrypted code, text or nothing)


    Addressing

    Addressing

    • SIP-URL sip:[email protected]

      • sip:[email protected]

      • sip:[email protected]

      • sip:[email protected]

  • Can accept parameters

    • sip:[email protected]&priority=urgent

    • sip:[email protected]&subject=Bluetooth

  • Can be identified by generic URIs

    • kanata.systems.mitel.com

    • tel:13334442343


  • Request message

    INVITEACKOPTIONSBYEREGISTERCANCEL

    NOTIFYSUBSCRIBEREFERMESSAGE

    Request Message

    INVITE:sip:[email protected] SIP/2.0From: Kathy <sip:[email protected]>To: Daniel <sip:[email protected]>

    Contact: sip:[email protected]: [email protected]_phone.strat_techContent-Type: application/sdpContent-Length: 147

    CSeq: 1 INVITE

    v=0o=UserA 2890844526 2890844526 IN IP4 here.coms=Session SDPc=IN IP4 100.101.102.103t=0 0m=audio 49172 RTP/AVP 0a=rtpmap:0 PCMU/8000

    Request Line

    MessageHeader

    MessageBody


    Response message

    Response Message

    SIP/2.0 200 OK

    Via: SIP/2.0/UDP kanata.mitel.com

    From: Kathy <sip:[email protected]>

    To: Daniel <sip:[email protected]>

    Call-ID: [email protected]_phone.strat_techContact: sip:[email protected]: 1 INVITE

    Status Line

    Status Codes

    1xx Informational: - Trying - Ringing - Being Forwarded - Queued

    200 Success

    3xx Redirect

    4xx Client Error

    5xx Server Error

    6xx Global Error

    MessageHeader

    MessageBody


    Request performatives

    Request Performatives

    • INVITE “Would you like to chat?”

    • ACK“Thanks, received your confirmation. Let’s start chatting”

    • BYE“Okay, I’m ending the call now.”

    • CANCEL “Cancel that last request but don’t end the call”

    • OPTIONS“What functionality do you support?”

    • REGISTER“Direct all my calls to this phone.”

    Enables Mobility


    Invite method

    sip.kanata.mitel.com(stateful proxy)

    sip.ottawa.nortel.ca(redirect server)

    sip.mitel.com(stateless proxy)

    sip.nortel.com(stateful proxy)

    ACK

    302

    INVITE

    INVITE

    INVITE

    INVITE

    INVITE

    SIP/2.0 302 MOVED TEMPORARILY To: sip:[email protected] From: sip:[email protected] Call-ID: [email protected] CSeq: INVITE 1Contact: sip:[email protected];q=0.7, sip:[email protected];q=0.9,

    INVITE sip:[email protected] SIP/2.0Via: SIP/UDP/2.0 sip.kanata.mitel.com Via: SIP/UDP/2.0 sip.mitel.com To: sip:[email protected] From: sip:[email protected] Contact: sip:[email protected] Call-ID: [email protected] CSeq: INVITE 1

    INVITE sip:[email protected] SIP/2.0Via: SIP/2.0/UDP sip.kanata.mitel.com Via: SIP/2.0/UDP sip.mitel.com To: sip:[email protected] From: sip:[email protected] Contact: sip:[email protected] Call-ID: [email protected] CSeq: INVITE 1

    INVITE sip:[email protected] SIP/2.0 Via: SIP/2.0/UDP sip.kanata.mitel.com Via: SIP/2.0/UDP sip.mitel.com Via: SIP/2.0/UDP sip.nortel.comTo: sip:[email protected] From: sip:[email protected] Contact: sip:[email protected] Call-ID: [email protected] CSeq: INVITE 1

    INVITE sip:[email protected] SIP/2.0Via: SIP/UDP/2.0 sip.kanata.mitel.com Via: SIP/UDP/2.0 sip.mitel.com To: sip:[email protected] From: sip:[email protected] Contact: sip:[email protected] Call-ID: [email protected] CSeq: INVITE 1

    ACK sip.ottawa.nortel.ca SIP/2.0To: sip:[email protected] From: sip:[email protected] Call-ID: [email protected] CSeq: INVITE 1

    INVITE sip:[email protected] SIP/2.0Via: SIP/UDP/2.0 sip.kanata.mitel.com To: sip:[email protected] From: sip:[email protected] Contact: sip:[email protected] Call-ID: [email protected] CSeq: INVITE 1

    INVITE Method

    CUA

    sip:[email protected]

    SUA

    sip:[email protected]


    Responses and ack method

    sip.kanata.mitel.com(stateful proxy)

    sip.ottawa.nortel.ca(redirect server)

    sip.mitel.com(stateless proxy)

    sip.nortel.com(stateful proxy)

    200 OK

    ACK

    200 OK

    ACK

    200 OK

    ACK

    200 OK

    ACK

    ACK sip:[email protected]: SIP/2.0/UDP sip.kanata.mitel.com Via: SIP/2.0/UDP sip.mitel.com Via: SIP/2.0/UDP sip.nortel.comTo: sip:[email protected] From: sip:[email protected] Contact: sip:[email protected] Call-ID: [email protected] CSeq: ACK 1

    SIP/2.0 200 OKVia: SIP/2.0/UDP sip.kanata.mitel.com Via: SIP/2.0/UDP sip.mitel.com Via: SIP/2.0/UDP sip.nortel.comTo: sip:[email protected] From: sip:[email protected] Contact: sip:[email protected]: [email protected] CSeq: INVITE 1

    Responses and ACK Method

    CUA

    sip:[email protected]

    SUA

    sip:[email protected]


    Bye method

    sip.kanata.mitel.com(stateful proxy)

    sip.ottawa.nortel.ca(redirect server)

    sip.mitel.com(stateless proxy)

    sip.nortel.com(stateful proxy)

    BYE Method

    BYE

    BYE

    CUA

    BYE

    sip:[email protected]

    SUA

    BYE [email protected] SIP/2.0Via: SIP/2.0/UDP sip.kanata.mitel.com Via: SIP/2.0/UDP sip.nortel.comTo: sip [email protected] From: sip: [email protected] Contact: sip:[email protected]: [email protected] CSeq: 2 BYE

    sip:[email protected]


    Options method

    OPTIONS

    OPTIONS

    UserAgentServer

    UserAgentServer

    200 OK

    200 OK

    UserAgentClient

    UserAgentClient

    SIP/2.0 200 OK

    Via: SIP/2.0/UDP kanata.mitel.comTo: sip:[email protected]: sip:[email protected]: OPTIONS 12 Call-ID: 1234556677 Allow: INVITE,ACK,OPTIONS,CANCEL,REFERAccept: application/sdp;level=1, text/htmlAccept-Language: da, en-gb,q=0.8, en;q=0.7

    OPTIONS:sip:[email protected] SIP/2.0

    Via: SIP/2.0/UDP kanata.mitel.comTo: sip:[email protected]: sip:[email protected]: OPTIONS 12 Call-ID: 1234556677

    OPTIONS:sip:[email protected] SIP/2.0

    To: sip:[email protected]: sip:[email protected]: OPTIONS 12 Call-ID: 1234556677

    OPTIONS Method

    SIP Proxy

    sip:[email protected]

    sip:[email protected]


    Register method

    UserAgentServer

    UserAgentClient

    REGISTER Method

    LocationServer

    REGISTER

    SIP Registrar

    200 OK

    sip:[email protected]

    SIP Proxy

    SIP/2.0 200 OK

    To: sip:[email protected]: sip:[email protected]: 1 REGISTER Contact: sip:[email protected]&expires=12:00Call-ID: 1234556677

    REGISTER:sip:registrar.systems.mitel.com SIP/2.0

    To: sip:[email protected]: sip:[email protected]: 1 REGISTERContact: sip:[email protected]&expires=12:00Call-ID: 1234556677


    Sip extensions 3pcc

    SIP Extensions - 3PCC

    *** These methods have been added to extend SIP to support third party control. They enable external applications to control SIP Agents ***

    • REFER“Please go to this other place and do this”

    • SUBSCRIBE “I would like to monitor your call activity.”

    • NOTIFY“An event occurred.”


    Refer method

    REFER

    INVITE

    UserAgentServer

    UserAgentServer

    UserAgentClient

    UserAgentClient

    INVITE sip:[email protected] SIP/2.0

    To: sip:[email protected]: sip:tomsphone.mitel.comContact: sip:tomsphone.mitel.comCSeq: INVITE 1 Call-ID: [email protected]

    REFER: sip:tomsphone.mitel.com SIP/2.0

    Call-ID: [email protected] Refer-To: <sip:[email protected]>

    REFER Method

    Dialer

    sip:tomsphone.mitel.com

    sip:[email protected]


    Sip call flow examples

    SIP Call Flow Examples

    Tom Gray

    Strategic Technology


    Call forward busy

    INVITE

    INVITE

    100 Trying

    486 Busy

    ACK

    INVITE

    180 Ringing

    180 Ringing

    200 OK

    200 OK

    ACK

    ACK

    Call Forward Busy

    Carole

    Bob

    Alice

    Proxy

    Alice Calls Bob

    Bob is CFB

    to Carole


    Consultation hold 1

    INVITE

    INVITE

    100 Trying

    180 Ringing

    180 Ringing

    200 OK

    200 OK

    ACK

    ACK

    2 Way Communication

    Consultation Hold - 1

    Carole

    Bob

    Alice

    Proxy

    Alice Calls Bob

    who then

    Consults with

    Carole and Returns to Alice

    Standard Pattern

    for Originating a Call


    Consultation hold 2

    Consultation Hold - 2

    Carole

    Bob

    Alice

    Proxy

    INVITE (Hold)

    INVITE (Hold)

    Bob Puts Alice

    On Hold

    Do Re-Invite in

    Same Session to

    Change Call Parameters

    200 OK

    200 OK

    ACK

    ACK

    Audio Path Knocked Down


    Consultation hold 3

    Consultation Hold - 3

    Carole

    Bob

    Alice

    Proxy

    INVITE

    Bob Calls Carole

    Make New Call

    for Consultation

    INVITE

    100 Trying

    180 Ringing

    180 Ringing

    200 OK

    200 OK

    ACK

    ACK

    2 Way Audio


    Consultation hold 4

    BYE

    BYE

    200 OK

    200 OK

    Audio Path Deleted

    INVITE

    INVITE

    100 Trying

    200 OK

    200 OK

    ACK

    ACK

    2 Way Audio Path Established

    Consultation Hold - 4

    Carole

    Bob

    Alice

    Proxy

    Drop Consultation Session

    Re-Invite in Existing Session to Restore Call to Alice


    Third party call control 1

    SUBSCRIBE

    200 OK

    REFER (Alice (Invite))

    INVITE

    NOTIFY

    200 OK (NTFY)

    180 Ringing

    200 OK

    ACK (Invite)

    200 OK (Refer)

    2 Way Audio

    Third Party Call Control - 1

    Bob

    Alice

    Carole’s PDA

    Carole’s Phone

    Carole

    uses a

    PDA Application

    to set up a

    conference

    with Alice and Bob

    Subscribe to Phone

    and Set Up Call to Alice


    Third party call control 2

    Third Party Call Control - 2

    Bob

    Carole’s Phone

    Alice

    Carole’s PDA

    REFER (Alice (Hold))

    INVITE (Hold)

    200 OK

    To Start Conference

    Put

    Alice on Hold

    ACK

    200 OK

    Audio Path Knocked Down


    Third party call control 3

    REFER (Refer(Alice)(Bob)))

    REFER (Invite(Bob))

    INVITE

    200 OK

    ACK

    200 OK

    200 OK

    Third Party Call Control - 3

    Bob

    Alice

    Carole’s PDA

    Carole’s Phone

    REFER (Bob)

    INVITE

    Tell Phone to Set Up

    Call To Bob

    and with

    Same Call ID

    Tell Alice

    Conference with Bob

    180 Trying

    200 OK

    ACK

    200 OK


    Third party call control 4

    200 OK

    2 Way Audio

    Third Party Call Control - 4

    Bob

    Alice

    Carole’s PDA

    Carole’s Phone

    INVITE

    180 Ringing

    Alice Calls

    Carole’s Phone

    Carole’s PDA

    is Notified

    -

    Refers Phone

    to Re-Invite

    To Set Up

    Speech path

    NOTIFY

    200 OK

    REFER

    INVITE

    200 OK

    ACK


    The ietf call processing language cpl

    The IETF Call Processing Language (CPL)

    Ramiro Liscano

    Strategic Technology

    Based on the IETF Draft: draft-ietf-iptel-cpl-04.ps


    System requirements

    Service Logic

    Programming Interface

    Requests

    Requests

    SIP Server

    Function

    Responses

    Responses

    System Requirements

    • Programming Telephony (SIP) Services

    SIP-CGI (Trusted Parties) or CPL (Un-trusted Parties)


    Language requirements

    Language Requirements

    • Verifiable: Well-formed and executable.

    • Guaranteed to complete: No loops.

    • Safe to execute: Restrained environment.

    • Standardized Representation:

    • Readable and Producible: human or machine.

    • Protocol Independent:

      • Independent of Operating System or Signaling Protocol

    • Ease of Transport: File representation.


    Iptel route signaling example

    Corporate

    Server

    Departmental

    Server

    Outgoing

    Proxy

    Route 1: Originator Signals through Servers

    End System

    Destination

    End System

    Originator

    CPL

    CPL

    CPL

    Route 2: Originator Directly Contacts Destination

    CPL

    CPL

    IPTel Route Signaling Example

    • Internet Telephony Signaling servers cannot know state of end systems they “control” since signaling may bypass them.


    Cpl definition

    Succeeded

    Failed

    Outcome 1

    Outcome 2

    Action 1

    True

    Condition

    Action 2

    False

    CPL Definition

    • A Language used to describe and control Internet Telephony Services.

    • Designed to be implemented on either Network Servers or User Agent Servers.

    • Describes Services as a Decision Graph based on XML Syntax.


    Cpl usefulness

    CPL Usefulness

    • Script Creation by End Users (Personal Assistance Functionality)

      • Customized call filtering.

    • Third Party Outsourcing

      • A standardized language.

    • Administrator Service Definition

      • Define enterprise policies.

    • Web Middleware

      • Service creation and customization using WEB interfaces.


    Cpl script functionality

    CPL Script Functionality

    • In a Signaling Server controls proxy, redirect, or rejection actions for the set-up of a call. Replaces SIP-CGI?

    • Focused on “local” control rather than “global” coordination of multiple signaling servers as in IN architecture.

    • Defines a list of Condition/Action Pairs that concentrates on user “location” routing.

    • Controversial Question: Should a CPL script execute on the END System?


    Creating and transporting cpl scripts

    Creating and Transporting CPL Scripts

    • CPL is easily created using “text” editors or “SGML” type of editors.

    • Script needs to be transported onto a CPL-enabled network server. (Currently no standard agreed upon)

      • WEB Uploading

      • SIP Register method.

      • SOAP (Simple Object Access Protocol)

    • All approaches require user authentication and script persistency.


    Which script is executed in progress

    Which Script is executed? (In Progress)

    • Scripts are associated with a particular Internet telephony address: SIP To or From: [email protected]

    • One script/user executes at a time.

      • Originator before Destination

      • Administrator scripts before user scripts.

    • Only one script for a particular event. Newer script substitutes old script.

      • Problems with compound and “Otherwise” tag conditionals.


    Motivation for using cpl

    Motivation for Using CPL

    • CPL is not Turing-complete and does not support loops or recursion. It is guaranteed to terminate.

    • Script resources are bounded under a proposed standard and therefore execution of the script is guaranteed.

    • CPL can be easily created and manipulated because interpreter can manage all conditions specified in the language.


    Cpl high level structure

    CPL High Level Structure

    • Call Processing Actions

      • Top-Level Actions (<incoming> OR <outgoing>)

      • Subactions (Non-recursive actions called from other actions)

    busy

    Location

    url:sip:jones@

    example.com

    proxy

    timeout: 10s

    Call

    Address-switch

    field: from

    subfield:host

    timeout

    failure

    Subdomain-of:

    example.com

    Location

    url:sip:jones@

    voicemail.

    example.com

    redirect

    otherwise

    Voicemail


    Cpl code example

    A Switch based on an Address of the Call Request

    Field = origin | destination | original destination

    Subfield = address-type | user | host | port | tel | display

    SIP Mappings: origin = From:

    original destination = To:

    Top Level Actions to Take on User’s Incoming Call

    Triggers on Incoming Call

    Destination = Owner

    SIP Trigger: INVITE

    Location Modifier

    Used to Add or Remove locations from location set

    Action to Take

    IF origin host = example.com

    Alternative Actions

    CPL Code Example

    <cpl>

    <subaction id="voicemail">

    <location url="sip:[email protected]"> <redirect />

    </location>

    </subaction>

    <incoming>

    <address-switch field="origin" subfield="host">

    <address subdomain-of="example.com">

    <location url="sip:[email protected]">

    <proxy timeout="10">

    <busy> <sub ref="voicemail" /> </busy>

    <noanswer> <sub ref="voicemail" /> </noanswer>

    <failure> <sub ref="voicemail" /> </failure>

    </proxy>

    </location>

    </address>

    <otherwise>

    <sub ref="voicemail" />

    </otherwise>

    </address-switch>

    </incoming>

    </cpl>


    Cpl signaling actions

    Redirect Action

    Directs calling party to place call to set of locations.

    Immediately terminates CPL.

    SIP Signaling:

    Server sends 3xx response.

    Proxy Action

    Causes call request to be forwarded to the locations in the location set.

    CPL chooses “adequate” response to the call attempt.

    If “successful” CPL terminates.

    SIP Signaling:

    busy = 486 | 600 response

    redirection = 3xx response

    failure = other 4xx | 5xx | 6xx resp.

    no-answer = no response.

    CPL Signaling Actions

    <subaction id="voicemail">

    <location url="sip:[email protected]">

    <redirect />

    </location>

    </subaction>

    <incoming>

    <address-switch field="origin" subfield="host">

    <address subdomain-of="example.com">

    <location url="sip:[email protected]">

    <proxy timeout="10">

    <busy> <sub ref="voicemail" /> </busy>

    <noanswer> <sub ref="voicemail" /> </noanswer>

    <failure> <sub ref="voicemail" /> </failure>

    </proxy>

    </location>

    </address>

    <otherwise>

    <sub ref="voicemail" />

    </otherwise>

    </address-switch>

    </incoming>


    Other types of switches

    Other Types of Switches

    • Time Switch

      • start, end, duration, freq, until, byday, etc.

      • Based on Internet Calendaring and Scheduling Core Object Specification (iCal COS), RFC 2445.

    <time dtstart=“19970105T083000” duration=“PT10M”

    freq=“yearly” interval=“2” bymonth=“1” byday=“SU”>

    Starting Jan 5th, 1997 08:30 for 10 minutes.

    Every Sunday in January from 08:30-08:40 every other year.

    • Priority Switches

      • Based on Priority Tags (emergency, urgent, normal, non-urgent)


    Other types of switches cont

    Other Types of Switches (cont.)

    • String Switch

      • Decisions can be based on free-form strings present in a call request.

      • Five fields defined

        • subject - subject of call.

        • Organization - organization of the originator of the call.

        • user-agent - program | device that made the call.

        • Language - language of choice.

        • Display - free-form text meant to be displayed with call.


    Cpl server extensions

    CPL Server Extensions

    • All CPL extensions are indicated by XML namespaces. <extension has=URL>

    • Examples

      • Querying how a Call has been Authenticated.

      • Richer control over H.323 addressing.

      • Mid-call or end-of-call controls.

      • End system specific features.

      • Support for Regular Expression Matching.


    Sip activities

    SIP Activities

    Daniel Amyot

    Strategic Technology


    Sip is only part of the big picture

    SIP is Only Part of theBig Picture…

    • Multiple Standardization Activities Related to SIP, including:

    JAIN

    PINT

    SDP

    SIP-T

    SPIRITS

    Others…

    TRIP

    SOAP

    SIP and CPL at Mitel

    New Research Topics?


    Standardization activities sip and sdp

    Standardization Activities:SIP and SDP

    • SIP: Session Initiation Protocol

      • RFC 2543, March 1999 (Proposed Standard)

      • Current Internet Draft: RFC 2543 bis-02, November 2000

    • SDP: Session Description Protocol

      • Used to describe sessions in INVITE request

      • SIP implementations MUST understand SDP


    Standardization activities trip

    Standardization Activities:TRIP

    • A Framework for Telephony Routing over IP

      • No global "directory of gateways" of phone numbers

      • Given an input telephone number, determine the address of a telephony gateway

    • Telephony Routing over IP (TRIP)

      • TRIP supports the discovery and exchange of IP telephony gateway routing tables between providers

      • Location servers (LS) sharing information

      • Not limited to routing; TRIP also handles selection of services, people, and other resources

      • Independent of signaling protocol, and can handle multiple such protocols simultaneously (SIP, H.323, etc.)

      • 4th Internet Draft, November 2000 (almost standardized)


    Standardization activities pint and spirits

    PINT

    SPIRITS

    Standardization Activities:PINT and SPIRITS

    • PINT = PSTN/Internet Interworking

      • PINT Service Protocol: Extensions to SIP and SDP for IP Access to Telephone Call Services

    • SPIRITS = Service in the PSTN/IN Requesting InTernet Service

      • Control of Internet applications from PSTN/IN

    PSTN, IN, Cell…

    Internet


    Standardization activities sip for telephony wg sip t

    Standardization Activities:SIP for Telephony WG (SIP-T)

    • BCP-T

      • Best Current Practice for Telephony Interworking

      • Inter-MGC communication using SIP

      • Informational draft, obsoletes SIP+

    • MIME Media Types for ISUP and Q.SIG Objects

      • Used for interoperability with legacy systems and services

      • Internet draft, November 2000


    Standardization activities sip and soap

    Standardization Activities:SIP and SOAP

    • SOAP (IBM/Microsoft)

      • Simple Object Access Protocol (W3C Note)

    • SIP and SOAP

      • Generic and extensible framework through which SIP nodes can request additional services from remote nodes

      • SOAP transported through SIP SERVICE message rather than HTTP

      • Candidate XML-based RPC mechanism for CPL

      • Internet Draft, June 2000


    Standardization activities jain sip

    Standardization Activities:JAIN SIP

    • Java API for Integrated Networks (JAIN)

      • Sun’s Java-based APIs for the rapid development of Next Generation telecom products using EJB

      • Two levels: Application/Call Control and Protocol

    • JAIN SIP

      • Portable interface to share information between SIP Clients and SIP Servers

      • Standard API for SIP stacks

      • Proposed Final Draft almost available


    Standardization activities jain sip1

    Standardization Activities:JAIN SIP

    JAINSIP


    Other activities

    Other Activities

    • Interworking between H.323 and SIP Networks

      • Internet draft of requirements, October 2000

      • Also under study by ITU-T (Question 13/16)

    • Call Control (transfer, conference, 3PCC…)

      • Informational only

    • Caller preferences

    • SNMP Management Information Base (MIB)

    • Applications (SIMPLE, IFAX…)

    • For more activities… http://www.softarmor.com/sipwg/tasks/index.html


    Sip and cpl at mitel

    SIP and CPL at Mitel

    • Research projects

      • Policy Description Language(PDL — extends CPL functionalities)

      • Service Description Languages

      • Human Aspects

      • Participants

        • U. of Ottawa (Logrippo) / U. of Waterloo (Atlee)

        • U. of Ottawa (Karmouch)

        • U. of Stirling (Turner / Magill, Scotland)

        • Dalhousie University (Jost)

        • Concordia University (Radhakrishnan)

        • U. of Toronto (Wellman)

    • SIP and CPL used in internal projects


    New research topics

    New Research Topics?

    • Policies

      • Representation

      • Negotiation and Conflict Handling (FI)

    • Applications

      • Scalable Execution Frameworks

      • Security

        • Autorisation, authentication

        • Middle Box Handling (firewalls, NATS, …)

      • Performance Monitoring and Enforcement

    • Interworking

      • Between Autonomous Systems

      • With Legacy Systems (including SS7, H.323, …)

    • Human Factors

      • Privacy, Controllability, Understandability

      • Appropriate Levels of Context Representation


    Thank you

    Thank You

    • Strategic Technology, Mitel Systems.

      • [email protected]

      • [email protected]

      • [email protected]

      • [email protected]


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