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1722.1 Enumeration & Connection Management presented by Chris Pane. 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. Definitions.
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1722.1 Enumeration & Connection Managementpresented by Chris Pane 1722.1 F2F April 7, 2010
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. 1722.1 F2F April 7, 2010
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. 1722.1 F2F April 7, 2010
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. 1722.1 F2F April 7, 2010
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. 1722.1 F2F April 7, 2010
AVB Network startup flow Zero Configuration (IP Address/Svc Discovery) Control Link Handshake Enumerate Stream Connection Mgmt SRP 1722.1 F2F April 7, 2010
Control Link • TCP Client Server Model • Talkers/Listeners - Servers • Controllers - Clients • Once established, AMP enumeration and stream connection management commands can flow. 1722.1 F2F April 7, 2010
Example 1: Network Device Configuration Video In 1 SPDIF_Left SPDIF_Right AMP Video Out 1 TCP/IP Connection Controller 1722.1 F2F April 7, 2010
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 1722.1 F2F April 7, 2010
Proposed property Tree 1722.1 F2F April 7, 2010
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 1722.1 F2F April 7, 2010
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. 1722.1 F2F April 7, 2010
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. 1722.1 F2F April 7, 2010
AMP Device Example 1722.1 F2F April 7, 2010
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 can’t be handled by the device “Hard Fail” • An SRP request fails, causing a “Soft Failure” condition 1722.1 F2F April 7, 2010
Open Items • Multiple controller configurations • Locate Functionality ? • Redundant Streams ? • Protocol Design Document 1722.1 F2F April 7, 2010