Session Policy Framework Draft draft-ietf-sipping-session-policy-framework-01

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Session Policy Framework Draftdraft-ietf-sipping-
session-policy-framework-01
Volker Hilt volkerh_at_bell-labs.com Gonzalo
Camarillo Gonzalo.Camarillo_at_ericsson.com Jonathan
Rosenberg jdrosen_at_cisco.com
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Status and Changes

• Submitted as WG item.
• draft-ietf-sipping-session-policy-framework-00
• draft-ietf-sipping-session-policy-framework-01
• Editorial changes and added more descriptive
  text.
• IANA Considerations section now contains the
  registration details for new headers.
• Improved Security Considerations section.
• UA and policy server should perform mutual
  authentication.
• Policy servers should use SIPS URIs.
• UA should communicate with proxy via TLS.

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Changes Session-independent Policies

• Added architecture diagram.
• Mandated support for the Media Policy Data Set
  format in NOTIFY bodies.

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Changes Session-specific Policies (1)

• Added an optimization for policies that only
  apply to the local session description.
• Some policies only apply to the local session
  description of a UA.
• Policy server can indicate that it wants to
  police the local but not the remote session
  description.
• UA may skip sending the remote description.
• Reduces message overhead in case the remote
  description has not yet been sent and message
  size.

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Changes Session-specific Policies (2)

• SUBSCRIBE/NOTIFY-based mechanism on policy
  channel.
• Session-specific Policy Event Package.
• Removed the PUBLISH/SUBSCRIBE/NOTIFY alternative
  from draft.
• Closes the remaining major open issue!

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Overview
UA A
Proxy A
PS URI
Policy Server A
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Next Steps

• No open issues for the framework.
• Reviewers needed!

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Event Package for Session-Specific
Policiesdraft-ietf-sipping-policy-package-01

• Volker Hilt
• volkerh_at_bell-labs.com
• Gonzalo Camarillo
• Gonzalo.Camarillo_at_ericsson.com

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Status and Changes

• Submitted as WG item.
• draft-ietf-sipping-policy-package-00
• draft-ietf-sipping-policy-package-01
• Editorial changes and clarifications.
• Improved Security Considerations section.
• UA should authenticate a policy server, e.g., via
  TLS.
• Policy server should authenticate the UA, e.g.,
  via SIP or TLS.
• Policy servers should use SIPS URIs.

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Changes (cont.)

• New Examples section providing call flows and
  message details.
• New event header parameter local-only for
  NOTIFY requests.
• Indicates that the notifier only needs the local
  session description.
• Subscriber may stop sending the remote
  description within the current subscription.

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Open Issue 1 Body Format (1)

• Which format for SUBSCRIBE and NOTIFY bodies?
• SUBSCRIBE body contains session information
  (e.g. session description, target URI, )
• NOTIFY body contains session policy
• Option 1 SDP
• UA includes local/remote SDP announcement.
• Policy server returns SDP announcements that are
  modified according to current policies.
• Simple
• Not all session parameters can be expressed in
  SDP (e.g. target URI).
• Requires MIME multipart bodies and new content
  disposition types to carry local AND remote
  session description.
• UA needs to make sure that it fully supports the
  modified SDP announcement.

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Open Issue 1 Body Format (2)

• Option 2 XML-based Media Policy Dataset
• UA generates a media policy dataset document for
  current session.
• Policy server returns policies as media policy
  dataset document.
• No dependencies on session description format.
• Format can support all relevant session
  parameters and is extensible.
• Local and remote session descriptions/policies
  can be transmitted in one document.
• Same formats as for session-independent policies.
• Easy to encode policy decisions that go beyond
  modifications of SDP (e.g. session needs to be
  terminated).
• Requires UA to generate and parse these XML
  documents.
• Note Media Policy Datatset does not yet support
  the required functionality.

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Open Issue 2 Session Information

• Which information should a UA submit to the
  policy server?
• Option 1 SDP announcement
• Option 2 use a basic set of elements
• We already have identified a basic set of policy
  elements for the Media Policy Dataset.
• Media Types, Codecs, and Bandwidth
• In addition media IP addresses and ports, target
  URI.
• UA should provide these, if available.

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Next Steps

• Proposal
• Option 2 Use XML-based Media Policy Dataset
• Extend the Media Policy Dataset

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A User Agent Profile Data Set for Media
Policydraft-ietf-sipping-media-policy-dataset-01
Volker Hilt volkerh_at_bell-labs.com Gonzalo
Camarillo Gonzalo.Camarillo_at_ericsson.com Jonathan
Rosenberg jdrosen_at_cisco.com
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Status

• No changes since last meeting.
• Depends on
• A Schema and Guidelines for Defining Session
  Initiation Protocol User Agent Profile Data Sets
  (draft-petrie-sipping-profile-datasets-03.txt)
• Usage within the session-specific policy event
  package.