2.3.9 IP over DVB (ipdvb)

NOTE: This charter is a snapshot of the 64th IETF Meeting in Vancouver, British Columbia Canada. It may now be out-of-date.

Last Modified: 2005-09-27

Chair(s):

Gorry Fairhurst <gorry@erg.abdn.ac.uk>

Internet Area Director(s):

Mark Townsley <townsley@cisco.com>
Margaret Wasserman <margaret@thingmagic.com>

Internet Area Advisor:

Margaret Wasserman <margaret@thingmagic.com>

Mailing Lists:

General Discussion: ipdvb@erg.abdn.ac.uk
To Subscribe: majordomo@erg.abdn.ac.uk
In Body: subscribe ipdvb at majordomo@erg.abdn.ac.uk
Archive: http://www.erg.abdn.ac.uk/ipdvb/archive/

Description of Working Group:

The WG will develop new protocols and architectures to enable better
deployment of IP over MPEG-2 transport and provide easier interworking
with IP networks. Specific properties of this subnetwork technology
include link-layer support for unicast and multicast, large numbers of
down-stream receivers, and efficiency of transmission.

These properties resemble those in some other wireless networks. The
specific focus of the group is on the use of MPEG-2 transport
(examples include the Digital Video Broadcast (DVB) standards: DVB-RCS;
DVB-S and DVB-T and related ATSC Specifications) in next generation
networks and is not concerned with the development, replacement, or
retention of existing protocols on the existing generation of networks.

The WG will endeavour to reuse existing open standard technologies,
giving guidance on usage in IP networks, whenever they are able to
fulfill requirements. For instance, we acknowledge the existing
Multiprotocol Encapsulation (MPE) [ATSC A/90;ETSI EN 301192] and that
this will continue to be deployed in the future to develop new
markets. Any alternative encapsulation would need to co-exist with MPE.

Appropriate standards will be defined to support transmission of IPv4
and IPv6 datagrams between IP networks connected using MPEG-2
transport subnetworks. This includes options for encapsulation, dynamic
unicast address resolution for IPv4/IPv6, and the mechanisms needed to
map routed IP multicast traffic to the MPEG-2 transport subnetwork.
The
standards will be appropriate to both MPE and any alternative
encapsulation method developed. The developed protocols may also be
applicable to other multicast enabled subnetwork technologies
supporting large numbers of directly connected systems.

The current list of work items is:

Specify the requirements and architecture for supporting IPv4/IPv6 via
MPEG-2 transmission networks. Such requirements should consider the
range of platforms currently (or anticipated to be) in use. This draft
will be an Informational RFC.

Define a standards-track RFC defining an efficient encapsulation
method. The design will consider the need for MAC addresses, the
potential need for synchronisation between streams, support for a wide
range of IPv4/IPv6 and multicast traffic.

Provide an Informational RFC describing a framework for unicast and
multicast address resolution over MPEG-2 transmission networks. The
document will describe options for the address resolution process,
relating these to appropriate usage scenarios and suggesting
appropriate protocol mechanisms for both the existing Multi-Protocol
Encapsulation (MPE) and the efficient encapsulation (2). Consideration
will be paid to existing standards, and the cases for IPv6 and IPv4
will be described.

Define standards-track RFC(s) to specify procedures for dynamic
address resolution for IPv4/IPv6. This will describe the protocol and
syntax of the information exchanged to bind unicast and multicast flows
to the MPEG-2 TS Logical Channels.  This will include specific
optimisations appropriate for networks reaching large numbers of
down-stream systems.

Goals and Milestones:

Done  Draft of a WG Architecture ID describing usage of MPEG-2 transport for IP transmission.
Done  Draft of a WG ID on the new Encapsulation.
Done  Submit Architecture to IESG
Done  Draft of a WG ID on the AR Framework, specifying mechanisms to perform address resolution.
Done  Submit Encapsulation to IESG
Jan 2006  Draft of a WG ID defining Security Requirements for the ULE protocol
Mar 2006  Submit AR Framework to IESG
Apr 2006  Draft of a WG ID defining an IP Address Resolution (AR) protocol
Aug 2006  Submit ULE Security Requirements to IESG
Dec 2006  Progress the Encapsulation RFC along the IETF standards track
Jan 2007  Submit AR Protocol to IESG

Internet-Drafts:

  • draft-ietf-ipdvb-ule-06.txt
  • draft-ietf-ipdvb-arch-04.txt
  • draft-ietf-ipdvb-ar-01.txt

    No Request For Comments

    Current Meeting Report

     
    þÿ Minutes of the IP over Digital Video Broadcast WG (IPDVB)

===========================================================

TUESDAY, 13:00-15:00 November 8, 2005

Chair: <gorry@erg.abdn.ac.uk>

WG Note-taker: Martin Stiemerling <stiemerling@netlab.nec.de>





1. Agenda

---------

(WG Chair, Gorry Fairhurst)



This was the 5th meeting of the IPDVB WG at the IETF. The meeting was

chaired by Gorry Fairhurst. The proposed agenda was accepted. An

additional presentation by Axel Jahn on IP over DVBS.2 had been

received, which the WG Chair would present.





2. Document Status 

------------------

(WG Chair, Gorry Fairhurst)



Active WG Drafts:

    draft-ietf-ipdvb-ule-06.txt (Proposed Standard)

        RFC Editor queue in EDIT IANA.

    draft-ietf-ipdvb-arch-04.txt (Informational)

        RFC Editor's queue in Auth48 call.

    draft-ietf-ipdvb-ar-01.txt

        Active WG draft.



Protocol entries for ULE has been created in registries at:

    ISO/SMPTE

    ATSC

    IANA Next-Header registry



These registry assignments are now permanent.



Other related documents Individual Drafts for consideration by WG:

    draft-stiemerling-ipdvb-config-01.txt

    draft-cruickshank-ipdvb-sec-req-00.txt

    draft-cruickshank-ipdvb-sec-00.txt

    draft-cantillo-ipdvb-s2encaps-01.txt



There had been a re-charter of the WG Charter milestones, after

the last IETF meeting. A new item added on ULE security requirements.

The new milestones are progressing well and all completed on time.





3. Presentation on IP Address Resolution

----------------------------------------

(draft-ietf-ipdvb-ar-01.txt) Marie-Jose Montpetit



Marie-Jose presented an overview of the document structure and noted

that this must work in all MPEG-2 networks: address resolution should

be technology agnostic. The I-D was to: Define terminology, lead to

a common understanding, review implementation scenarios. Address

resolution should also be considered above IP and the goal is how

to make the implementation more IP friendly.



The I-D is applicable to whatever MPEG-2 transmission is used

(satellite, cable, handheld, ...) and presents methods to ensure AR

is network-aware / technology agnostic (mobility of solutions) and

speaks about integration into multiple signaling paradigms: DVB-SI

and IMS/SIP; This can resolve other parameters: encapsulation method,

MTU, policy/priority/QoS, security, packing threshold.



The current revision -01 is now in good shape. Updates include:

    Added description of use of SI.

    Various things based-on discussion on the list.

    Fixes to document format.

    

She presented the intended work for I-D rev. -02:

    Investigate integration into other new trends:

    SIPPING, ipconfig, autoconf;

    Closer integration into other standards bodies;

    Inputs are requested from the WG on mobility, DVB-H, IMS;

    Also: cable/broadcast strategies usage, IP streaming over MPEG-2.



    Gorry Fairhurst: There are a lot of things that could be added.

    How long  until the I-D is ready for a WGLC?

    Marie-Jose Montpetit: This is some kind of shopping list, we

    propose to cycle it one or two more times, and get comments

    from the list.  The I-D should be ready by early next year.

    Gorry Fairhurst: The milestone is March 2007.

    Marie-Jose Montpetit: Seems OK.

    Gorry Fairhurst: I encourages people to read next draft, and

    offer contributions where able.





4. Presentation on IP Address Configuration

-------------------------------------------

(draft-stiemerling-ipdvb-config-02) Martin Stiemerling



There has been progress, the I-D has been reorganised, and is now

ready for comments from the WG. Open issues include the configuration

parameters, sets of configuration items, and how to reconfigure?

The I-D still needs to differentiate between the configuration roles

of the MPEG-2/DVB operator and IP operator. There is no current

conclusion on whether new protocols are needed?



    Marie-Jose Montpetit: The I-D speaks about MPEG-2/DVB and IP

    operators.  What about content provider configuration?

    Martin Stiemerling: That's a good question.  It should enter

    the picture somewhere.

    Marie-Jose Montpetit: All these people have configuration.

    Martin Stiemerling: If we talk about IP-level questions, then

    I am not sure they are involved, if this is at the service-level,

    then there is configuration.



    Gorry Fairhurst: Does anyone have NDP experience in very flat

    networks - i.e. scalability to large numbers of systems?

    Marie-Jose Montpetit: The Secure Neighbor Discovery WG (send)

    has work on scaling, captured in an RFC. This is important to

    the AR I-D.

    Martin Stiemerling: I will look into this point.



    Gorry Fairhurst: Is the I-D heading towards an Informational

    RFC.  Should the outcome be part of another I-D?

    Martin Stiemerling: There can be recommendations on DHCP, NDP,

    arp, etc.

    Gorry Fairhurst: This seems to fall within the Chartered item

    on Address Resolution.  We may finally need to consider whether

    this I-D should be combined with the AR draft.  For now, I am

    very happy to see the I-D proceed, and would like to see

    contributions.





5. Presentation Security Requirements

-------------------------------------

(draft-cruickshank-ipdvb-sec-req-00) Sunil Iyengar



A security I-D had been presented at IETF-63 (in Paris). The

proposed L2 security method is based on an analysis of ULE. It had

received many good comments at the previous meeting, but also some

important questions from the IETF Security Area. This new I-D

responds to these comments. It mainly describes threats and security

requirements. The L2 security association is between an Encapsulation

Gateway and the Receiver.



A number of issues have been brought up on the mailing list. The

authors are reading these and intend to work through them on the

mailing list after the IETF meeting. The intention is to revise the

document in December 2005, collect more feedback, and finally ask

the WG to adopt it against the new Milestone.



    Marie-Jose Montpetit: The I-D speaks about MPEG-2/DVB and IP

    operators.  What about content provider configuration?

    Martin Stiemerling: That's a good question.  It should enter

    the picture somewhere.

    Marie-Jose Montpetit: All these people have configuration.

    Martin Stiemerling: If we talk about IP-level questions, then

    I am not sure they are involved, if this is at the service-level,

    then there is configuration.



    Gorry Fairhurst: Does anyone have NDP experience in very flat

    networks - i.e. scalability to large numbers of systems?

    Marie-Jose Montpetit: The Secure Neighbor Discovery WG (send)

    has work on scaling, captured in an RFC. This is important to

    the AR I-D.

    Martin Stiemerling: I will look into this point.



    Gorry Fairhurst: Is the I-D heading towards an Informational

    RFC.  Should the outcome be part of another I-D?

    Martin Stiemerling: There can be recommendations on DHCP, NDP,

    arp, etc.

    Gorry Fairhurst: This seems to fall within the Chartered item

    on Address Resolution.  We may finally need to consider whether

    this I-D should be combined with the AR draft.  For now, I am

    very happy to see the I-D proceed, and would like to see

    contributions.    



6. Presentation Security Method

-------------------------------

(draft-cruickshank-ipdvb-sec-00) Sunil Iyengar



This was the same I-D that had been presented at IETF-63. The authors

will keep this draft alive while the requirements I-D matures, and

update it.  There will a new version -01 at the end of January 2007.





7. DVB-S.2 Framework

--------------------

(WG Chair, Gorry Fairhurst)



Gorry presented one slide showing the position of the new DVB-S.2

physical-layer within the protocol stack. This was expected to

become a widely deployed standard and support existing ULE, MPE, etc

via a transport stream interface. There was also a direct mapping

of IP packets into the physical layer, known as the Generic Stream.

This was under study in DVB-GBS, and was the topic for the next few

presentations. There is an opportunity here to ensure that the two

modes of DVB-S.2 have a common IP interface (e.g. based on ULE).





7.1 DVB-S2 Encapsulation ­ GBS Activities

-----------------------------------------

(prepared by Axel Jahn, presented by Gorry Fairhurst)



Axel was responsible for S.2 IP Encapsulation work within DVB-GBS.

The presentation described how DVB-GBS intends to define S.2

encapsulation requirements and evaluation criteria (see slides).



The IP/S.2 group will send a copy of their document to the ipdvb

mailing list. The group is asking for potential encapsulation methods.

Next year, the comparison and evaluation would start. Many ipdvb WG

members are already participating in this process, others are welcome

via a DVB member. 





7.2 Requirements for IP over DVB-S.2

------------------------------------

(draft-cantillo-ipdvb-s2encaps-01) Juan Cantillo



Juan presented a framework for IP encapsulation using Generic Streams.

This version of the I-D has been completely rewritten, based on

comments on and off the list. He presented a list of pending issues

concerning the I-D. The next step is to propose this as a WG item.

This is a hot topic, but does the WG scope cover DVB-S.2?



    Martin Stiemerling: What is the fragmentation problem?

    Juan Cantillo: ULE fragments SNDUs in MPEG-2, in S.2 BBframes

    have no defined method for flexible fragmentation.

    Martin Stiemerling: We already have ULE, is fragmentation out

    of scope?

    Gorry Fairhurst: I'm not sure this is the same problem, let's

    take questions about scope later.

    

    Josef Schmidbar: Are there any plans to utilize the different

    modulation options and link these to the IP QoS?

    Juan Cantillo: I am not aware of any work yet, most current

    systems also use MPEG-2 at constant rate. QoS could be added

    to the I-D.  The authors would welcome ideas and text for this.

    

    Mark Watson:  What is the relation between physical layer FEC

    and packet-level FEC? The physical layer is not necessarily the

    best place to expend effort to ensure overall reliability. Can

    the whole stack be optimised?

    Juan Cantillo: We are hopeful about driving ideas on cross-layer

    optimizations between L2 and L3. This topic needs to explored,

    and has many implications on IP. We are not yet talking about

    application optimisation, this is in the longer term.

    Gorry Fairhurst: You have to consider about applications/transport

    if you need to understand the loss/error requirements of specific

    flows.  Packet FEC, is now an important IETF Transport Area

    topic, with documents in AVT and RMT WGs, and a BoF this IETF

    (FECFrame). This WG is not the only place in the IETF to address

    this topic.

    Juan Cantillo: There are potential some tools in S.2, that we

    can use for example the ISI field.

    

    Gorry Fairhurst (WG Chair): The Charter defines what the WG

    should do. Any change needs to be discussed with our Area

    Director (and the IESG). Anyway, the WG should not duplicate

    what is done in another organisation. Axel's contribution seems

    to clarify things. It seems to methat the I-D is more focussed

    on IP and there is no overlap.  This may compliment work in

    DVB-GBS by bringing Internet experience.





How many had read draft-cantillo-ipdvb-s2encaps-01?

(6 people had read the document)



How many people think the WG has expertise to work on this topic?

(6 people had read the document)



The authors should continue to revise this I-D, and the WG should

pursue this topic on the mailing list. The protocol specification

is not a valid WG item: It would therefore be premature to propose

any Milestone in this space within the ipdvb WG.





8. ULE Implementation Status

----------------------------

(WG Chair, Gorry Fairhurst)



Gorry presented a list of known implementations. Once ULE is

published as an RFC, implementors should be encouraged to bring their

code up to the proposed standard.  There is another new implementor

working on trial open source for a ULE Gateway. No details were

available yet, but we should expect an announcement in a few months,

this will complement the existing open-source Receiver.  He asked if

there were any news  from other implementors?



    Josef Schmidbar: University of Salzburg had contributed to the

    Linux ULE release (now a standard feature of the kernel), and

    had recently discovered a small bug. The treatment of the D-bit

    (destination NPA/MAC address suppressed) was wrong when D=0

    (specified MAC/NPA address) and a multicast L2 address was used.

    This could lead to unexpected packet loss for IPv4/IPv6 multicast.

    Gorry Fairhurst: Was this implementation going to be fixed?

    Josef Schmidbar: Yes, and it would be uploaded to the Linux

    distribution.



27 people were in the meeting room, and some also participated via

jabber/audio. The session ended at 2:30pm.

    Slides

    1.2. Agenda & Document Status
    3. Address Resolution (AR)
    4. IP Address Configuration for ipdvb
    5. IPDVB Security Requirements
    6. ULE Security Extension
    7b. DVB-S2 Encapsulation
    7a. DVB-S2 Encapsulation
    7. IP Encapsulation for DVB-S.2