ANCP Protocol Design Team Update: Multicast extensions

1
ANCP Protocol Design Team Update Multicast
extensions

• Philippe Champagne, Stefaan De Cnodder,
• Roberta Maglione, Sanjay Wadhwa

71st IETF - Philadelphia
2
Agenda

• ANCP Multicast Extensions
• Modes of Operation
• Message Types
• Message Flows
• General Message Format
• Open Issues
• Next Steps

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Modes Of Operation

• AN terminates IGMP from subscriber.
• AN interacts via ANCP with NAS to perform
  conditional access and bandwidth based admission
  control. If the flow is admitted, AN replicates
  multicast flow to the subscriber. OR
• AN autonomously makes the decision to admit a
  flow for the subscriber. If the flow is admitted,
  AN replicates multicast flow to the subscriber
• NAS directly learns of the request for multicast
  flow from the subscriber (either by terminating
  IGMP from the subscriber, or via other means e.g.
  application level signaling).
• NAS performs per-subscriber conditional access
  and bandwidth based admission control. NAS
  controls replication state on the AN via ANCP.

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ANCP Multicast Messages
Sub-Message Type
Details
Message Type

• Purpose
• Download Conditional access information
• from NAS to AN.
• Contents
• Profile Name OR white/black/grey lists

Conditional Access Update Message Direction NAS
? AN
Multicast Control Messages

• Purpose
• For NAS to create or delete replication
• state on AN.
• Contents
• One or more S/,G, ACI, Action add/delete
• Time/Volume based accounting ON/OFF

Replication Control Message Direction NAS ? AN
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ANCP Multicast Messages
Message Type
Sub-Message Type
Details

• Purpose
• AN asking NAS before adding
• a port to a multicast flow. NAS can perform
• bandwidth admission control and/or access
  control.
• AN notifying NAS to release resource
• Contents
• S,G or ,G , ACI , Action request or
  release
• ,, Action request or release

Admission Request Message Direction AN ? NAS
Multicast Request Messages

• Purpose
• NAS asking AN to report active flow
  information.
• OR
• NAS asking AN to trigger admission request
• for all active flows. AN to clear all
  replication
• state, and generate admission-request for
  each
• flow for which it has received IGMP ??
• Contents
• S/,G or ,
• Optional admission-request retrigger flag

Active-Flow Request Message Direction NAS ? AN
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ANCP Multicast Messages
Details
Message Type
Sub-Message Type

• Purpose
• Generated to provide response to an
• admission request from AN.
• Contents
• S/,G, ACI
• Time/Volume based accounting ON/OFF
• Failure code (present in ANCP header)

Admission Response Message Direction NAS ? AN
Multicast Response Messages

• Purpose
• AN reporting one or more active flows.
• Contents
• One or more S/,G records where each
• record can contain
• list of ACI, bandwidth, stats
• creation time, last update time etc.

Active-Flow Report Message Direction AN ? NAS
Multicast Status Message Direction AN ? NAS

• Purpose
• ACK/NACK (if requested) for Multicast
• Control Messages (Conditional Access
• update message or Replication Control
• Message)
• Contents
• Command-sequence
• Code in case of failure

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Message Flow
NAS
AN
Conditional Access Update
IGMP join for white list accept
Admission-Request Message
IGMP join for grey list Ask
Admission Response Message
StreamingMulticast Flow
Active-Flow Request Message
Active-Flow Report Message
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Message Flow (example 2)
NAS
HGW
IGMP Join
Access Control Bandwidth Admission Control
AN
Replication Control Message
StreamingMulticast Flow
Multicast Status Message
Active-Flow Request Message
Active-Flow Report Message
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ANCP Multicast Packet Format

• Keep existing GSMP header.
• GSMP message type in the header extended for
  multicast. New types to be defined for Multicast
  Control, Multicast Request, and Multicast
  Response messages.
• Payload to contain Extension Block as defined
  in the protocol draft.
• Extension block has more specific multicast
  message type, and one or more TLVs specific to
  that message type.

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General Packet Format

• 0 1 2
  3 0 1 2 3 4 5 6 7 8 9
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  ----------------------
  ---------- Vers Sub
  Message Type Result Code
  --------------------
  ------------ Partition
  ID Transaction Identifier
  -----------------
  --------------- I
  SubMessage Number Length
  ---------------
  -----------------
  
  
  Message Payload
  
  -----------
  ---------------------

• Message Type
• Multicast Control Message
• Multicast Request Message
• Multicast Response Message

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Message Payload

• -------------------------
  -------
• xxxxxxxx Message Type     Tech Type  
  Block Length 
• -------------------------
  -------
•                                       
                          
•                          Extension
  Value                      
•                                                  
               
• -------------------------
  -------
• Tech Type 0xFF (Base specification use ie
  technology independent)
• Message Type Conditional Access,
  Replication Control,
• Admission Request,
  Active-Flow Request
• Admission Response,
  Active-Flow Report
• "Extension Value" contains one or more TLVs   
• -------------------------
  -------       
•              of TLVs         Extension block
  length (bytes)
• -------------------------
  -------      
•                                                  
               
•                                                  
                

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Open Issues

• Conditional Access
• What kind of configuration models should be
  supported? Do we need
• capability negotiation for different models ?
• Referential Model
• Profiles containing white, black and grey list
  pre-configured on AN via means other than ANCP.
  When user logs in, NAS sends a conditional
  access update message to indicated the profile
  relevant to the user, based on the subscription.
• Profiles containing white, black and grey list
  pre-configured on AN via ANCP. When user logs in,
  NAS sends a conditional access update message
  to indicated the profile relevant to the user,
  based on the subscription.
• Non-Referential Model
• When user logs in, NAS provides actual contents
  of white, black and grey lists relevant to the
  user, based on the users subscription. This is
  suitable for a-la-carte access model.

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Open Issues

• We would like to use existing TLVs for ACI.
• Is it useful to provide support for indicating
  what is contained in the ACI string?

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Open Issues

• Is it useful to provide multiple control
  operations in a single message (e.g. provide
  delete for a flow, followed by an add via a
  single replication control message (swap
  semantics).
• Behavior on failure needs to be clearly defined
  e.g. if first operation fails, should the second
  operation be executed?

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Next steps

• Closure on open issues
• Consider design and specification for the
  following
• Accounting
• Flow-Groups
• Graceful Restart
• Detailed packet formats

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Questions/Feedback?
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Thank You
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Message Types

• 2 Categories of messages
• Multicast Control Messages (From NAS to AN)
• Conditional Access Update (Sends a
  White/Grey/Black List to AN)
• Admission-Control Message
• Can be in response to an Admission-Request
  Message or
• Can be an unsolicited Control message
• Multicast Request/Status Messages (both ways)
• Admission-Request Message
• Active-Flow Request Message (NAS ask for list of
  current flows)
• Multicast Status Message (AN reports
  error/success using this message)
• Multicast Active-Flow Report (AN reports the list
  of Active Flow)

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Packet Format

• Keep existing GSMP header
• New GSMP message type
• For conditional access
• For Admission Control Message
• For Admission Request
• For Admission Response (and Spontaneous)
• etc

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Open Issues

• How to address conditional Access
• Profile-id provided in message but profile
  definition not configured via ANCP (mandatory)
• Profile-id with profile definition configured via
  ANCP
• List directly configured via ANCP (no concept of
  profiles)
• Should ANCP Multicast extension be considered
  generic and tech independent?
• Do we need to provide support for identifying
  what is contained in the ACI string?
• Make sense to support multiple transaction in
  single message (like a swap,) Transaction to
  be atomic? Is sequencing required/a must?
• Concept of Flow groups issues to be resolved
  (will it be too complex?)

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Questions/Feedbacks?

• Should we handle Flow groups now or later?
• Active-Flow Report (NAS getting the list of
  active flow on the AN)