1722.1 Enumeration

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1722.1 Enumeration Connection
Managementpresented by Chris Pane
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Intent

• Present a straw man vision of how an AVB stream
  enumeration and connection protocol could work
  for 1722.1.
• Present vision from a top down, end to end point
  of view. Details will follow.

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Definitions

• Controller An entity on the network that
  provides runtime stream allocation and connection
  requests.
• AMP AVB Management Protocol
• Channel - Media Content
• Node Element in the property tree that
  represents a hierarchical level.
• Property A settable entity on a channel.

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Requirements

• Atomic creation/removal of streams.
• Configuration of streams (channels, settings)
• Runtime channel status updates (Renamed input)
• Error handling back to controller.
• Must support the ability to learn about already
  configured streams (i.e. Multiple Controllers).
• Listeners and Talkers must be able to restore
  state without the controller present on network.

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Assumptions

• An AVB network can be comprised of
  Talkers/Listeners and Controllers.
• The IP address of Talkers and Listeners have
  already been provided and decided upon (via
  1722.1 Discovery).
• Talkers and Listeners have already allocated
  their stream address ranges via MAAP.
• The scope is limited to stream creation,
  connection and teardown only.

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AVB Network startup flow
Zero Configuration (IP Address/Svc Discovery)
Control Link Handshake
Enumerate
Stream Connection Mgmt
SRP
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Control Link

• TCP Client Server Model
• Talkers/Listeners - Servers
• Controllers - Clients
• Once established, AMP enumeration and stream
  connection management commands can flow.

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Example 1 Network Device Configuration
Video In 1
SPDIF_Left
SPDIF_Right
Video Out 1
AMP
TCP/IP Connection
Controller
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Property Tree

• Properties are presented to clients in a tree
  fashion (similar to a hierarchical filesystem).
• A minimal subset of properties are defined and
  must exist in all implementations.
• Wild card queries are supported
• Client can request that a place in the properties
  tree is maintained by the server during life of
  control link

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Proposed property Tree
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System Node (/System)

• All devices must provide the /System Node
• It will contain system information such as
• Current Streams
• Device specific settings (Vendor ID, Manufacture
  Id, )
• .others

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AMP Commands

• Handshake Used to establish protocol parameters
  for use on the control link.
• ACK Acknowledge response when no data is
  expected back from a command.
• EnumerateNode Used to request from a device that
  it list a set of nodes given a specified node
  path on the tree.

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AMP Commands (Continued)

• EnumerateProps Request that a device enumerate
  the properties that may exist on a given node.
• GetProp Request the possible property values
  for a given property.
• SetAnchor Request that the device remember the
  location within the property tree that the user
  is currently at. Stays valid until control link
  is broken.
• PublishStream Request that a specified stream
  be created atomically given the channels and
  properties that are specified in the command
  invocation.
• ListenStream Request that a listener connect to
  a stream.

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AMP Device Example
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AMP Device Example (Continued)

• When a device is processing a Publish stream
  request, it will be taking care of the SRP
  Talker/Listener SRP logic
• A stream publish can fail if
• The caller has requested something that cant be
  handled by the device Hard Fail
• An SRP request fails, causing a Soft Failure
  condition

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Open Items

• Multiple controller configurations
• Locate Functionality ?
• Redundant Streams ?
• Protocol Design Document