ANCP Multicast Extensions draft-ancp-mc-extensions-00.txt

1
ANCP Multicast Extensions draft-ancp-mc-extension
s-00.txt

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

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Agenda

• ANCP Header
• Multicast Replication Control Messages
• Open Issues
• Proposal

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ANCP Header

• 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
• ---------------------
  -----------
• Type (0x88-0C)
  Length
• ---------------------
  -----------
• Vers Sub Message Type Result
  Code
• ---------------------
  -----------
• Partition ID Transaction
  Identifier
• ---------------------
  -----------
• I SubMessage Number
  Length
• ---------------------
  -----------
• 
  
• Message Payload
  
• 
  
• ---------------------
  -----------

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Transaction ID Field

• Used to distinguish between different Request
  messages and to associate a Response Message to
  the corresponding Request
• It should be incremented linearly for each new
  message in the range (1, 224 - 1)
• Transaction Identifier sequencing must be
  maintained independently for each ANCP adjacency
  and per message type
• Message types not requiring response/request
  correlation (such as events) should set the
  Transaction Id field to 0x0

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Result field

• Result field is derived from RFC3292 and renamed
  Result Code, it has the following codes
• Nack Res 0x1 - Result code indicating that no
  response is expected to the message other than in
  cases of failure
• AckAll Res 0x2 - Result code indicating that
  a response to the message is requested in all
  cases. Not used in Event messages
• Success Res 0x3 - Allowed to be set in
  Response Messages only to communicate successful
  execution of all directives in a previous Request
  Message
• Failure Res 0x4 - Allowed to be set in
  Response Messages only to communicate failure of
  execution of one directives in a previous Request
  Message

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Multicast Replication Control Messages

• Multicast Replication Control Request
• Sent by the NAS to the AN with a directive to
  either join or leave one or more multicast flows
• Message Type 0x90
• Multicast Status Response Message
• Sent by the AN to the NAS in response to a
  Multicast Replication Control Request
• Message Type 0x91

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Message Flow
---------- ------- -----
ANCP ----- Subscriber Home
AN lt--------------gt NAS ----------
Gateway ----- -----
-------


Replication-Crtl(
Target,add Flow1)
lt--------------------
Mcast Flow 1
lt

Replication-Response
(status)

--------------------gt

Replication-Crtl(
Target,delete
Flow1)
lt--------------------

ltStop Replication of x
Mcast Flow 1gt
Replication-Response
(status)
--------------------gt
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Replication Control Request

• Transaction Identifier
• The sender must populate the ANCP Transaction ID
  field with a distinct non-zero linearly
  incrementing value for each Request per adjacency
• Result Field
• The sender must set the Result to either
  "AckAll" or "NAck ("NAck" is the default)
• Message Payload
• Target Type TLV
• Command TLV

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Replication Control Request

• 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
• ---------------------
  -----------
• Type Target-Type TLV
  Length of Target-Info
• ---------------------
  -----------
• 
  
• Value Target-Info
  
• 
  
• ---------------------
  -----------
• Type Command TLV
  Length of Command Info
• ---------------------
  -----------
• 
  
• Value
  Command-Info
• 
  
• ---------------------
  -----------

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Target TLV

• The Target-type TLV (0xTBD) is a generic wrapper
  TLV for a class of objects (single Access-Line,
  group-of-access-lines, etc.) Future definition of
  new targets requires the asssignment of new
  target type numbers
• This TLV is intended to be re-usable across
  the messages
• Example of Target-type TLV for a single
  Access-Line
• 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
• ---------------------
  -----------
• TLV Type Target-type
  Target-TLV Length
• ---------------------
  -----------
• Access-Loop-Circuit-ID0x0001
  Circuit-ID Length
• ---------------------
  -----------
• 
  
• Access Loop Circuit
  ID
• 
  
• ---------------------
  -----------

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Command TLV

• The Command TLV (0xTBD) is a generic wrapper TLV
  and contains one or more multicast flow command
  directive(s) for a given target. This TLV is
  intended to be re-usable across the messages
• 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
• -----------------------
  ---------
• Command Code R O M Flags
  Command Length
• -----------------------
  ---------
• Addr Family Encoding Type Multicast
  Source Address
• -----------------------
  ---
• Addr Family Encoding Type Multicast
  Flow Address
• -----------------------
  ----

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Command TLV

• Command directives
• 0x01 - Add
• 0x02 - Delete
• 0x03 - Delete All
• Flags 8 bit General purpose Flag field
• R Resource Admitted Flag (only used for Add
  set to 1 to indicate resources reserved)
• O Flow Accounting if set in Add indicates that
  byte accounting for the flow is to commence
• M set to 1 if multicast flow is SSM, 0 for ASM
• Address Family

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Command TLV

• A single Multicast Replication Control Request
  Message may feature several commands, which will
  be interpreted sequentially. Each command is
  encapsulated in the Command TLV
• The sender MUST use separate Command TLVs for
  each distinct multicast flow
• The recipient of a Request message is to run an
  implicit directive numbering across the multiple
  directives in the message
• The recipient MUST process the directives in the
  order of reception and use the derived directive
  number in any response messages, besides the
  Transaction ID

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Command TLV

• The processing/execution of multiple directives
  contained in a single Multicast Control Request
  message MUST be interrupted at the first error,
  and the remaining commands in the Request message
  discarded
• In case of failure of one directive a multicast
  control response message MUST be sent indicating
  the command number that resulted in the error
  along with the error code
• When the strict sequenced processing of the
  directives in a single Multicast Replication
  Control Request message is not required the
  directives must be distributed across separate
  request messages

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Replication Control Response

• Transaction Identifier
• A Response message must use the same ANCP
  Transaction ID as that in the original Request
  Message
• Result Field
• Is used to report Success or Failure status
• Message Payload
• A Replication Response Message indicating Success
  should consist only of the base ANCP header with
  no body, however it may contain one or more TLVs
• A Replication Response Message indicating Failure
  must contain an Status-Info TLV and should be
  followed by the Target-Type TLV

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Status-Info TLV

• The Status-Info TLV is a generic wrapper TLV that
  contains the status code regarding commands
  and/or requests and it may carry additional
  sub-TLVs
• This TLV is intended to be re-usable across
  the messages
• 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
• -----------------------
  ---------
• TLV Type Status-info
  Status TLV Length
• -----------------------
  ---------
• Result Code Cmnd Nmbr Error
  Message Length
• -----------------------
  ---------
• Error Message (aligned to 4 bytes
  length)
• -----------------------
  ---------
• sub-TLVs...
  
• -----------------------
  ---------

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Status-Info TLV

• Command Number
• indicates the number of the command in the
  Request Message that resulted in an error
• Error Message codes
• 0x00 Success 0x01 -
  Malformed message
• 0x02 - Command not supported 0x03 - Flag set
  not supported
• 0x04 - Unrecognized Target Type 0x05 -
  Unsupported Address Family
• 0x06 - Malformed flow address 0x07 - No
  resources
• 0x08 - Unknown Port 0x09 - Target
  port down
• 0x0a - Configuration error 0x0b -
  Multicast flow does not exist
• 0x0c - Unsupported address encoding
• 0x0d - Additional info needed to execute command
• 0x0e -Multicast flow count exceeded
• 0x0f - M Flag set, but no IP Source address
  provided
• 0x10 - Transaction-id out of sequence

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Open Issues

• Determining the behaviour for (S,G) flows in case
  of SSM
• Do we need additional command directives?
• Modify?
• Lack of base protocol functionality for dealing
  with protocol errors (eg. missing TLVs)
• Which new capabilities have to be defined?
• Related ANCP MIB
• Others?

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Proposal

• To have the contents of this draft accepted by
  the WG and incorporated into section 4.4 of ANCP
  Protocol ID

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Questions/Discussion
Thanks!