2.8.20 Session Initiation Proposal Investigation (sipping)

NOTE: This charter is a snapshot of the 61st IETF Meeting in Washington, DC USA. It may now be out-of-date.
In addition to this official charter maintained by the IETF Secretariat, there is additional information about this working group on the Web at:

       Additional SIPPING Web Page

Last Modified: 2004-11-01


Gonzalo Camarillo <gonzalo.camarillo@ericsson.com>
Dean Willis <dean.willis@softarmor.com>
Rohan Mahy < rohan@ekabal.com>

Transport Area Director(s):

Allison Mankin <mankin@psg.com>
Jon Peterson <jon.peterson@neustar.biz>

Transport Area Advisor:

Allison Mankin <mankin@psg.com>

Mailing Lists:

General Discussion: sipping@ietf.org
To Subscribe: sipping-request@ietf.org
In Body: (un)subscribe
Archive: http://www.ietf.org/mail-archive/web/sipping/index.html

Description of Working Group:

The Session Initiation Protocol Project INvestiGation (SIPPING)
working group is chartered to document the use of SIP for several
applications related to telephony and multimedia, and to develop
requirements for any extensions to SIP needed for those applications.
Such requirements will be referred to the SIP working group for
development of any new SIP method or  Guiding principles for
the performance of SIPPING's work will include:

1. Documenting the requirements of specific chartered tasks.

2. Documenting the usage of SIP to solve real problems that need 
  to be solved in a standardized way.

3. Looking for commonalities among the chartered tasks and ongoing
  SIP-related development, as commonalities may indicate for general,
  reusable functionality in SIP.

4. Describing the requirements for any extension determined to  and
  handing them to the SIP WG.

5. Developing procedures and requirements for configuration and
  delivery of SIP User Profiles

Besides performing needed specification of several applications
of SIP, SIPPING can be seen as also working out use cases that
clarify the role of SIP in the Internet, and help to ensure that
Occam's razor is appropriately applied to SIP usage.

The security of all the deliverables will be of special importance.
The technology for security will be keyed from the SIP Security
specification within RFC 3261, and additional SIP specifications
as they apply.

The specific tasks for SIPPING will be:

1. PSTN and/or 3G telephony-equivalent applications that need 
  a standardized approach

  - informational guide to common call flows
  - requirements from 3GPP for SIP 
  - framework of SIP for telephony (SIP-T) 
  - call transfer and call-forwarding 
  - AAA application in SIP telephony
  - mapping between SIP and ISUP

2. Messaging-like applications of SIP 
  - support for hearing-/speech-impaired 
  - development of usage guidelines for subscribe-notify (RFC 2848,
    SIP events) to ensure commonality among applications using them,
    including SIMPLE WG's instant messaging.

3. Multi-party applications of SIP
  - the working group will review a number of technical pieces
    including call transfer, subscribe-notify,  SIP features
    negotiation, and session description protocol (SDP) capability   
    negotiation, and will develop requirements
    and a framework for multi-party conferencing with SIP.

4. SIP calling to media 
  - the working group will develop a requirements draft
    approach to SIP interaction with media servers. An example is
    whether a voicemail server is just a box that a caller can send an
    INVITE to.

5. SIP URI-List services
  - the working group will develop requirements for
    SIP list services mechanisms enabling a client to request that a
    server distribute a specific SIP request to a list of recipient
    URIs. The working group will develop a mechanism to transport this
    list of recipient URIs (a URI-list) from a SIP client to SIP server
    in conjunction with the request (a request-contained list). The
    working group will also specify mechanisms (presumed not to be SIP
    mechanims)for storing, modifying, or retrieving a URI-list stored
    on a server (stored URI-lists). The working group will specify the
    use of URI-lists with various SIP request types for which list
    services are appropriate with both stored and request-contained
    URI-lists. The working group will also develop requirements and
    specifications for a positive opt-in mechanism by which list
    servers can prevent amplification of attacks and relay abuses.

At a later time, the working group and chairs may request
of the Area Directors that new tasks be added to the charter.
Such additions to the charter will require IESG approval.

The group will work very closely with SIP working group.
The group will also maintain open dialogue with the IPTEL working
group, whose Call Processing Language (CPL) is related to the task
areas in a number of areas.  The group will also coordinate closely
with SIMPLE, AAA, and MMUSIC (SDP development).

SIPPING will also ensure compatibility with the work done
by the now concluded PINT working group.  SIPPING will encourage
active participation from the Distributed Call Signaling (DCS) Group
of the PacketCable Consortium for distributed telephony services, 3GPP,
3GPP2, and several ITU-T study groups.

Goals and Milestones:

Done  Submit Internet-Draft on SIP-Telephony Framework to IESG for consideration as a BCP
Done  Submit Internet-Draft on ISUP-SIP Mapping to IESG for consideration as Proposed Standard
Done  Submit Internet-Draft on Requirements for use of SIP to support telephony for the Hearing-Impaired to IESG for consideration as an Informational RFC
Done  Submit SIP 3rd party call control to IESG for consideration as BCP
Done  Submit Internet-Draft on 3G Requirements to IESG for consideration as an Informational RFC
Done  Submit Internet-Draft on Mapping ISUP Overlap Signaling to SIP to IESG for consideration as a Proposed Standard
Done  Submit Internet-Draft on Usage Guideline for Events (Subscribe-Notify) to IESG for consideration as an Informational RFC
Done  Submit Internet-Drafts Basic and PSTN Call Flows to IESG fro consideration as BCPs
Done  Requirements for Content Indirection in SIP
Done  Submit Message Waiting SIP event package to IESG for consideration as PS
Done  Using ENUM with SIP Applications to IESG for consideration as an Informational RFC
Done  Requirements for Reuse of Connections in SIP
Done  Submit Internet-Draft on T.38 Fax Call Flows to IESG for consideration as a BCP
Done  Requirements for SIP Request History
Done  Submit Internet-Draft on Requirements for AAA Application in SIP Telephony to IESG for consideration as an Informational RFC
Done  Sip Interworking with QSIG
Done  3pcc Transcoding to IESG as Info
Jul 04  KPML to IESG as PS
Aug 04  Conferencing Requirements to IESG as Info
Aug 04  Conferencing Framework to IESG as Info
Aug 04  Conferencing Call Control-Conferencing to IESG as BCP
Sep 04  Location Requirements to IESG as Info
Sep 04  End-to-Middle Security Requirements to IESG as Info
Sep 04  Requirements on Trait-Based Authorization to IESG as Info
Oct 04  Configuration Framework to the IESG as a PS
Oct 04  Submit Requirements and Framework for Exploders to the IESG as PS
Oct 04  Submit Opt-in/Opt-out Mechanism for Exploders to the IESG as PS
Oct 04  Submit URI List Transport Mechanism to the IESG as PS
Nov 04  Submit I-D on Ad-Hoc Conferencing using URI lists to the IESG as PS
Nov 04  Submit I-D on MESSAGE Exploders to the IESG as PS
Nov 04  Submit I-D on Multiple REFER to the IESG as PS
Nov 04  Submit I-D on Subscriptions to Ad-Hoc Resource Lists to the IESG as PS
Dec 04  Event Filtering Requirements to the IESG
Dec 04  Caller Preferences Use Cases
Dec 04  SIP Service Examples
Dec 04  Session Policy Requirements to IESG as Info
Jan 05  Session Independent Policy Mechanism to the IESG as PS
Feb 05  Transcoding with Conf Bridge to IESG as Info
Feb 05  Transcoding Framework to IESG as Info
Mar 05  Session Specific Policy Mechanism to the IESG as PS
Apr 05  Review charter with Area Directors and recharter or conclude


  • draft-ietf-sipping-service-examples-07.txt
  • draft-ietf-sipping-nat-scenarios-01.txt
  • draft-ietf-sipping-conference-package-06.txt
  • draft-ietf-sipping-torture-tests-04.txt
  • draft-ietf-sipping-3gpp-r5-requirements-00.txt
  • draft-ietf-sipping-cc-transfer-03.txt
  • draft-ietf-sipping-qsig2sip-04.txt
  • draft-ietf-sipping-config-framework-05.txt
  • draft-ietf-sipping-cc-conferencing-05.txt
  • draft-ietf-sipping-conferencing-requirements-01.txt
  • draft-ietf-sipping-conferencing-framework-03.txt
  • draft-ietf-sipping-session-policy-req-02.txt
  • draft-ietf-sipping-callerprefs-usecases-03.txt
  • draft-ietf-sipping-kpml-06.txt
  • draft-ietf-sipping-early-media-02.txt
  • draft-ietf-sipping-app-interaction-framework-03.txt
  • draft-ietf-sipping-e2m-sec-reqs-04.txt
  • draft-ietf-sipping-early-disposition-03.txt
  • draft-ietf-sipping-reason-header-for-preemption-02.txt
  • draft-ietf-sipping-transc-3pcc-02.txt
  • draft-ietf-sipping-location-requirements-02.txt
  • draft-ietf-sipping-session-indep-policy-01.txt
  • draft-ietf-sipping-uri-services-01.txt
  • draft-ietf-sipping-uri-list-00.txt
  • draft-ietf-sipping-uri-list-conferencing-01.txt
  • draft-ietf-sipping-uri-list-message-01.txt
  • draft-ietf-sipping-uri-list-subscribe-01.txt
  • draft-ietf-sipping-multiple-refer-01.txt
  • draft-ietf-sipping-certs-00.txt
  • draft-ietf-sipping-consent-reqs-00.txt
  • draft-ietf-sipping-consent-framework-00.txt
  • draft-ietf-sipping-toip-00.txt

    Request For Comments:

    RFC3324 I Short Term Requirements for Network Asserted Identity
    RFC3351 I User Requirements for the Session Initiation Protocol (SIP) in Support of Deaf, Hard of Hearing and Speech-impaired individuals
    RFC3372 BCP Session Initiation Protocol (SIP) for Telephones (SIP-T): Context and Architectures
    RFC3398 PS Integrated Services Digital Network (ISDN) User Part (ISUP) to Session Initiation Protocol (SIP) Mapping
    RFC3485 PS The Session Initiation Protocol (SIP) and Session Description Protocol (SDP) Static Dictionary for Signaling Compression (SigComp)
    RFC3578 PS Mapping of of Integrated Services Digital Network (ISUP) Overlap Signalling to the Session Initiation Protocol (SIP)
    RFC3665 BCP Session Initiation Protocol Basic Call Flow Examples
    RFC3666 BCP Session Initiation Protocol PSTN Call Flows
    RFC3680 Standard A Session Initiation Protocol (SIP) Event Package for Registrations
    RFC3702 I Authentication, Authorization and Accounting Requirements for the Session Initiation Protocol
    RFC3725 BCP Best Current Practices for Third Party Call Control in the Session Initiation Protocol
    RFC3824 I Using E.164 numbers with the Session Initiation Protocol (SIP)
    RFC3842 Standard A Message Summary and Message Waiting Indication Event Package for the Session Initiation Protocol (SIP)

    Current Meeting Report

    61th IETF SIPPING Minutes Minutes, SIPPING WG, 61th IETF

    Minutes edited by Gonzalo Camarillo

    Session 1, Tuesday, November 9, 2004, 0900-1130

    Meeting chaired by Gonzalo Camarillo, Rohan Mahy, and Dean Willis
    Notes by Ben Campbell and Spencer Dawkins

    Topic: Status

    Discussions led by: Chairs

    Chairs do not want to run too many working group last calls in parallel. The end-to-middle security work is scheduled for December, the conferencing bundle (four drafts) for January, and the URI-list services documents for February/March.
    3GPP needs the conferencing document by December (January would probably be OK as well).

    Topic: Configuration
    Discussions led by: Dan Petrie
    Relevant documents: draft-ietf-sipping-config-framework-04.txt and draft-petrie-sipping-profile-datasets-00.txt

    The configuration framework should work for low-end devices, but the datasets mechanism may not be supported by that type of device.
    The framework should not be very complex (e.g., rules to resolve conflicts in configuration date received from different sources may get too complex). We need to work on some use cases. think about requirements, and keep things as simple as possible. In particular, we need to think realistically about what low-end devices will need.

    Topic: Session-Independent Policies
    Discussions led by: Volker Hilt
    Relevant documents: draft-ietf-sipping-session-indep-policy-01.txt

    No significant discussions on the proposals in the slides. If somebody has any objection, he or she should express them on the list.

    Topic: Session-Specific Policies
    Discussions led by: Volker Hilt
    Relevant documents: draft-hilt-sipping-session-spec-policy-01.txt

    How does this work in a federation of domains? There is no communication between policy servers.
    The mechanism should be as simple as possible. Having use cases would be a good idea.

    Topic: URI-List Services
    Discussions led by: Gonzalo Camarillo
    Relevant documents: draft-ietf-sipping-uri-services-01.txt, draft-ietf-sipping-uri-list-conferencing-01.txt, draft-ietf-sipping-uri-list-message-01.txt, draft-ietf-sipping-uri-list-subscribe-01.txt, and draft-ietf-sipping-multiple-refer-01.txt

    URI comparisons are performed following the rules of the appropriate URI schemes (e.g., SIP URIs are compared using the rules for SIP URI comparison).
    Can user agents update the original URI-list provided to a conference server or to a resource list server in a SUBSCRIBE request. No, but future extensions may allow it. The drafts will be updated to reflect this.
    Will the consent-framework be a MUST implement here? Allison will provide input here.
    The disposition type of lists sent to user agents in MESSAGEs should be different than the disposition type of lists sent by user agents to URI-list services.

    Topic: Consent
    Discussions led by: Gonzalo Camarillo
    Relevant documents: draft-ietf-sipping-consent-reqs-00.txt  and draft-ietf-sipping-consent-framework-00.txt

    Do we want to mandate XCAP? We may not want to limit the applicability of this mechanism to user agents that support XCAP.
    Regarding the schema for permission documents, we need to think of low-end devices, but also on high-end devices that want to generate complex permission documents.

    Topic: Transfer
    Discussions led by: Alan Johnston
    Relevant documents: draft-ietf-sipping-cc-transfer-03.txt

    How to correlate a REFERs sent out of dialog with GRUUs is still an issue. Once we resolve this, the document will be ready for WGLC.

    Topic: End-to-middle Security
    Discussions led by: Kumiko Ono
    Relevant documents: draft-ietf-sipping-e2m-reqs-04.txt (currently under WGLC) and draft-ono-sipping-end2middle-security-03.txt

    The mechanism is probably SIP work (not SIPPING).
    What's the community interest in implementing this work? Significant but not overwhelming. Will be recommended to SIP via Allison.

    Topic: Caller Preferences Use Cases
    Discussions led by: Paul Kyzivat
    Relevant documents: draft-ietf-sipping-callerprefs-usecases-03.txt

    The draft is ready for WGLC

    Topic: GRUU Extensions to the Reg Event Package
    Discussions led by: Paul Kyzivat
    Relevant documents: draft-kyzivat-sipping-gruu-reg-event-01.txt

    Paul thinks the current draft has addressed all the open issues received to date, but not a lot of feedback has been received anyway. The draft needs more scrutiny.
    Those who are implementing the reg package will most likely implement this draft (based on sense of the room).

    Topic: Conferencing Framework
    Discussions led by: Jonathan Rosenberg
    Relevant documents: draft-ietf-sipping-conferencing-framework-03.txt (currently under WGLC)

    Discussions on the scope of this draft and its relation with the XCON framework. Allison will provide input on this issue.

    Session 2, Thursday, November 11, 2004, 900-1130

    Meeting chaired by Gonzalo Camarillo, Rohan Mahy, and Dean Willis
    Notes by Spencer Dawkins

    Topic: Real-time Text over IP
    Discussions led by: Arnoud van Wijk
    Relevant documents: draft-ietf-sipping-ToIP-00.txt

    Need to identify requirements for SIP extensions. It may be that everything in this document can be implemented with existing SIP mechanisms.

    Topic: Location Conveyance
    Discussions led by: James Polk
    Relevant documents: draft-ietf-sipping-location-requirements-02.txt

    The document will contain requirements and solutions (to meet some of the requirements at least). It will need to be decided whether the document stays in SIPPING or is sent to SIP.

    Topic: Event Package for Floor-related Information
    Discussions led by: Eunsook Kim
    Relevant documents: draft-ekim-sipping-conf-floor-package-00.txt

    Discussions will continue in XCON. More use cases are needed to understand the need of an alternative mechanism to fetch floor control information (BFCP already provides this information).

    Topic: Event Package for Device Information
    Discussions led by: Brijesh Kumar
    Relevant documents: draft-rahman-sipping-device-info-01.txt

    The authors will have a look at RFC 3259 (A Message Bus for Local Coordination) and at already existing event packages to see whether or not their requirements can be met with existing mechanisms.

    Topic: SIP and SPAM
    Discussions led by: Jonathan Rosenberg
    Relevant documents: draft-rosenberg-sipping-spam-01.txt

    Consensus in the room to make this draft a WG item. The chairs will talk to Allison.
    Not clear if this will be a requirements document or a framework document. This will need to be decided.

    Topic: Direct Transcoding
    Discussions led by: Kang
    Relevant documents: draft-taegyukang-sipping-transc-itg-00.txt

    The transcoding work has not advanced during the last meetings because the WG decided to finish other items, which are somehow related to transcoding, before (e.g., URI-list services for INVITE, session policies). The transcoding work will be resumed pretty soon, and it will take into account this type of scenario (the transcofing framework, which is a SIPPING WG item, actually tackles this type of transcoding already). The authors of this draft will send requirements to the transcoding design team.

    Topic: RTCP Summary Reports
    Discussions led by: Amy Pendleton
    Relevant documents: draft-johnston-sipping-rtcp-summary-04.txt

    Consensus in the room to make this draft a WG item. The chairs will talk to Allison. The next revision of the draft will most likely be ready for WGLC.

    Ad-Hoc Meeting on SBCs (Session Border Controllers), Tuesday, November 9, 2004, 1900-2100

    Meeting chaired by Gonzalo Camarillo and Jonathan Rosenberg
    Notes by Spencer Dawkins, Gaurav Kulshreshtha, and Steve Donovan

    This Ad-hoc meeting was organized to understand what functions are performing existing SBCs. The idea is to understand the requirements that have led implementers to use this type of entity and see whether these requirements can be met in a more SIP-friendly way (e.g., without breaking end-to-end principles).

    The requirements that came up during the discussions will be summarized in an Internet-Draft. At a later point it will be decided whether such a document turns into a survey document, requirements document, use cases... in any case, it seems valuable to have this type of information published.

    This work will be initially handled in SIPPING (i.e., the SIPPING mailing list is the right place to have discussions on SBCs at this point). If it turns out that this work is wider than just SIP, the area directors will find a home for it.


    Status and Agenda
    Caller Preferences Use Cases
    Registration Event Package
    Session Policy
    Consent Framework
    URI Services
    Profile Datasets
    Config Framework
    End-to-Middle Security
    RTCP Summary
    Floor Events
    Device Info