Internet Media Guides Update and Open Issues

1
Internet Media Guides Update and Open Issues

• Yuji Nomura, Pekka Luoma, Rod Walsh
• IETF-58, MMUSIC, 14.Nov.2003

2
Internet Media Guides Requirements Update

• Yuji Nomura
• IETF-58, MMUSIC, 14.Nov.2003

3
draft-ietf-mmusic-img-req

• Current draft-ietf-mmusic-img-req-00.txt
• A lot of changes from previous
• draft-nomura-mmusic-img-requirement-01.txt
  (individual submission)
• We will submit draft-ietf-mmusic-img-req-01 soon

4
draft-ietf-mmusic-img-req-00.txt

• Changes (1/3)
• 1. Introduction
• Background and Motivations (new)
• 3. Problem Statement (new)
• Moved and shortened from old framework draft
• 4. Requirements
• 4.4.2 Support for Intermittent Connectivity
• The system MUST enable IMG receivers with
  intermittent access to network resources

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draft-ietf-mmusic-img-req-00.txt

• Changes (2/3)
• 4.4.3 Congestion control
• Internet-friendly congestion control MUST be
  provided.
• 4.5 IMG Descriptions
• IMG metadata MUST be interoperable regardless of
  the transport protocol and network used to get it
• IMG metadata MUST be structured to enable
  fragmentation (e.g. of the global set of
  metadata)
• IMG metadata SHOULD support delta syntaxes for
  efficient messaging following small changes to
  metadata

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draft-ietf-mmusic-img-req-00.txt

• Changes (3/3)
• 5. Security Considerations (many changes)
• IMG Authentication and Integrity
• Privacy
• Access Control for IMGs
• Denial-of-Service attacks
• Replay Attacks

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Next steps and open issues

• For draft-ietf-mmusic-img-req-01.txt
• Numbering requirements
• Modify terminology for consistency
• Clarifications requested
• Many more receivers than senders
• Senders are continually connected (receivers are
  not)
• Tradeoff between customization and scalability
• WGLC on the horizon

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Internet Media Guides Requirements Update

• Questions???

9
Internet Media Guides Framework Update

• Pekka Luoma
• IETF-58, MMUSIC, 14-Nov-2003

10
draft-nomura-mmusic-img-framework

• Current draft-nomura-mmusic-img-framework-02.txt
• Previous
• draft-nomura-mmusic-img-framework-01.txt
  (individual submission)
• We will submit draft-ietf-mmusic-img-framework-00
  soon

11
draft-nomura-mmusic-img-framework-02

• Changes (1/2)
• 3. Use Cases Requiring IMG Framework
• Content-oriented use cases (new)
• 6. Applicability of Existing Protocols (new)
• New section (requested/agreed in Vienna)
• 6.1 Limitations of Existing Protocols
• 6.2 Existing Protocol Fit to the IMG Framework
  Model
• 6.3 Outstanding IMG Mechanism Needs

12
draft-nomura-mmusic-img-framework-02

• Changes (2/2) 6.3 Outstanding IMG Mechanism
  Needs
• Multicast Transport Protocol
• Maybe ALC-based
• Usage of Unicast Transport Protocols
• HTTP, SIP events,
• The Metadata Envelope
• New/single term for an existing framework model
  concept
• Gives independence from transport protocol and
  metadata format
• Baseline Data Model Specification
• Informative only, not MMUSIC/IETF standardized

13
draft-ietf-mmusic-img-framework

• Next steps and open issues (1/3)
• Editorial - clarifications, corrections of typos
• Terminology IMG, IMG metadata, IMG delivery,
• New section for whats in IETF scope - separated
  from outstanding IMG needs section
• In scope Transport protocols, transfer envelope
• Out of scope Data models, application specific
  metadata

14
draft-ietf-mmusic-img-framework

• Next steps and open issues (2/3)
• IMG Metadata identifier
• Probably a URI in all cases
• Differences between complete, delta and pointer
• Same id, different data type how to signal
  data type?
• Different syntax between complete and delta
• IMG metadata can refer to (and possibly locate)
  related metadata delivered over other transport
  channels and sessions, using the same
  locator/identifier as in the metadata envelope
• I.e. unify the identifier/locator for both
  metadata envelope and IMG metadata (suggestion
  for anyone specifying metadata)

15
draft-ietf-mmusic-img-framework

• Next steps and open issues (3/3)
• Submit revised version
• WGLC target December

16
Internet Media Guides Framework Update

• Questions???

17
Internet Media Guides Some Other Technical
Issues

• Rod Walsh
• IETF-58, MMUSIC, 14.Nov.2003

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Design Choices

• Multicast Transport Protocol
• ALC/FLUTE is a very good candidate
• Subscribe (unicast)
• SIP and SIP events
• Metadata Envelope
• a. XML file / wrapper
• b. Header extension of transport protocols
• Allow both methods? Or not?
• Data Types and Channelisation
• Could correlate data type and transport channel,
  e.g. pointer-only channel
• Could divide delivery over multiple channels
• Multicast multi-layer congestion control usage
• Both unicast and multicast channels could be
  employed

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Middlebox Authentication Integrity Issue

• A middlebox may combine, add, modify and remove
  metadata
• The original sender signature will be invalidated
  in some cases
• Solutions
• Trusted (by sender) middlebox re-signs using
  original authority
• Inter-domain trust issues
• Middlebox request to sender for new signing
  (post-modification)
• Middlebox just signs new and changed metadata
• Requires appropriately small fragmentation of
  metadata
• Possibly changeable metadata as small fragments,
  and stable metadata as large fragments
• (most applications we have discussed do not use a
  middlebox)

----------
---------- IMG
IMG
Sender ----
----gt Receiver
---------- \ /
---------- \
/ .
\ ----------- / .
. --gtIMG -----
. .
--gtTransceiver \ .
/ ----------- \
---------- /
\ ---------- IMG
/ ----gt IMG
Sender ----
Receiver ----------
----------
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Internet Media Guides Other Technical Issues

• Questions???

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Internet Media Guides Update and Open Issues

• Thanks !!!