NSWC-6-25-01.ppt

QoS Enabled A/V Streaming Irfan Pyarali Yamuna Krishnamurthy

Presentation Outline
Vanilla CORBA Audio/Video Streaming Service
QoS enabled A/V Streaming
AQoSA API design and implementation
UAV Application Design

CORBA Audio/Video Streaming Service
Goals of OMG CORBA A/V Service Specification
Define standard mechanisms for:
Stream Establishment
Stream Control
Multiple Flows
Multiple Protocols
QoS
Goals of TAO A/V Streaming Service Project
Implement OMG CORBA A/V Specification using TAO
Provide pluggable transport protocols
Provide QoS enabled streaming

Components in the CORBA A/V Service Stream EndPoint (Sink) Stream Interface Control Object Stream Adaptor POA ORB Control and Management Objects POA Stream EndPoint (Source) Stream Interface Control Object Multimedia Stream Stream Adaptor

A/V Streaming Interfaces
StreamCtrl
controlling the stream
MMDevice
interface for logical or physical device
StreamEndPoint
network specific aspects of a stream
Vdev
properties of the stream

request_connection StreamCtrl aMMDevice bMMDevice create _ A A_Endpoint, A_VDev create _ B B_Endpoint, B_VDev A _ Endpoint aVDev bVDev connect configure bind_devs (aMMDevice, bMMDevice) B_Endpoint Point-to-Point Streaming

Point-to-Multipoint Streaming
Asymmetrical- Only flow producers in source MMDevice, only flow consumers in sink MMDevice
Only sources are started and stopped
Sink can listen to any subset of flows
Solution based on IP Multicasting

Point-To-Multipoint Connection Establishment
The MCastConfigIF interface acts as the virtual sink
This interface keeps a list of the sinks
UDP multicasting is used to send and receive the actual data

A/V Streaming: Pluggable Protocols
Layers Pattern – Decoupled transport from flow protocols
Acceptor/Connector uses Flow_Factory interface to create protocol objects

QoS Enabled A/V Streaming
AV QoS Framework
QoS Transport (AQoSA)
QoS Mapping
QoS Monitoring
QoS Adaptation
ACE QoS API (AQoSA)
RAPI
GQoS

QoS Specification
//From Property Service
typedef string PropertyName;
struct Property{
PropertyName property_name;
any property_value;
};
typedef sequence<Property> Properties;
struct QoS {
string QoSType;
Properties QoSParams;
};
typedef sequence<QoS> streamQoS;
Two levels of specifying QoS
application (video frame rate)
network (bandwidth)
QoS definition is a named list of properties and their values

modify_qos(newQoS) method for QoS renegotiations
Changes the QoS associated with the stream
Empty the_spec means apply operation to all flows
Method on StreamCtrl, StreamEndPoint, Vdev interfaces
boolean
modify_QoS (
inout streamQoS new_qos, in flowSpec the_spec)
raises (
noSuchFlow,
QoSRequestFailed);
QoS Modification

QoS Negotiation
Negotiator interface is used to negotiate QoS between two stream endpoints
Negotiator interface is defined as a property of the StreamEndpoint
The negotiate() method is called when there is a change in the specified QoS
The negotiator can be derived by the user to perform application specific functionality
In the UAV scenario the QuO System Condition Object is derived from the Negotiator
interface Negotiator {
boolean negotiate (
in Negotiator remote_negotiator,
in streamQoS qos_spec);
};

AQoSA API
Binds flows to reservations in a uniform and portable way
Encapsulates application’s notion of the underlying network QoS
Separates QoS properties of its sessions from low-level socket data transfer aspects
Allows the application to specify and request QoS. Be notified if the QoS was not available
Updates itself based on QoS notifications
Portably wraps the QoS parameters
Implementation targets (RSVP) Resource reSerVation Protocol
RAPI & GQoS

AQoSA Architecture

AQoSA Session Design
AQoSA uses the BRIDGE pattern
Separate Abstraction and Implementor hierarchies
Abstraction : QoS Protocols
Implementor : QoS Protocol Impls .
Hierarchies separately extensible to include future QoS protocols and Impls.
Hides the class representation from clients
AQoSA uses a factory to manage the lifecycle of QoS sessions
Clients only need to relink not recompile

AQoSA Session Factory
AQoSA uses the ABSTRACT FACTORY pattern
Abstract Factory
QoS Session Factory
Concrete Factories
IntServ Protocol Factory
DiffServ Protocol Factory
Isolates the concrete classes
Switching factories allows us to change complete hierarchies of implementations without change of interfaces.
SINGLETON pattern

AQoSA Event Notification
AQoSA QoS events
Changes to Resource reservations
RSVP : RSVP events triggered through signaling
DiffServ : Non-signaling means
Problem
Different interfaces/models from different Service Providers
GQoS model: Modified socket API
RAPI model: RAPI Daemon
Native APIs => Inconsistent Application Design
Solution should be consistent with traditional ACE event handling model

AQoSA Event Notification
AQoSA uses the Reactor to listen to QoS Events
High level APIs
Inherent and Accidental complexity
Decouples demultiplexing/dispatching from QoS event handling
AQoSA notifies applications of QoS events when
A particular QoS state is accepted/rejected for the first time
The QoS state is updated
AQoSA enhances the existing ACE Event Handling model through DECORATOR PATTERN

QoS Decorator
Allows applications to continue using the ACE event handling model for QoS events
Associates QoS responsibilities to the ACE Event Handler dynamically
Only a single Event Handler registered with the reactor by the application for Read/Write/QoS

QoS Session/Socket Association
Many to Many relation
QoS Manager
Separates the QoS session from the Socket
Manages QoS sessions that a socket has subscribed to
Keeps the ACE SOCK classes lightweight
Manages the QoS FlowSpec Profiler

RAPI Sender Session Sender QoS_Session_Factory create Session ( ) qos_session qos_session open ( ) RAPI ACE_Sock_Dgram_Mcast_QoS subscribe ( ) qos ( ) QoS_Decorator init ( ) ACE_Reactor register_handler ( ) rapi_session ( ) QoS_Manager join_qos_session ( ) rapi_sender ( ) Create a RAPI Sender Session and initiate PATH Messages

RAPI Receiver Session Receiver QoS_Session_Factory create Session ( ) qos_session qos_session open ( ) RAPI ACE_Sock_Dgram_Mcast_QoS subscribe ( ) qos ( ) QoS_Decorator init ( ) ACE_Reactor register_handler ( ) rapi_session ( ) QoS_Manager join_qos_session ( ) rapi_reserve ( ) Create a RAPI Receiver Session and initiate RESV Messages

QoS Enabled Point-to-Point Streaming request_connection app qos network qos StreamCtrl aMMDevice bMMDevice create _ A A_Endpoint, A_VDev create _ B B_Endpoint, B_VDev A _ Endpoint aVDev bVDev connect configure (with QoS) QoS Mapper AQoSA create session reserve path bind_devs (aMMDevice, bMMDevice) qos events bind_devs (aMMDevice, bMMDevice, streamQoS) register session and callback QoS Monitor B_Endpoint change Negotiator negotiate modify_qos

Handling Changes in QoS QoS Monitor qos events AQoSA Shaping Filter Selection Filter Adapto r Adaptor Quo System Condition Object X X change adapt configure adapt Quo Contract modify

UAV Application Design Video Source Process UAV SIMULATION HOST UAV Video File Video DIstributor VIDEO DISTRIBUTION HOST QuO Contract VIDEO DISPLAY HOST 1 Video Display Proxy CORBA A/V Streaming Service + AQoSA Resource Reservation (IntServ) CORBA A/V Streaming Service
Reused Off the Shelf Software
DVDView video player
Common middleware services
TAO CORBA A/V Service
QuO
AQoSA
TAO Naming Service
Frame filtering commands Observed throughput Reservation requests Video Display VIDEO DISPLAY HOST 2 VIDEO DISPLAY HOST N

Asynchronous StartUp
Sender Up, No Receivers
Naming Service Sender resolve Sender bind Sender Sender Sender Receivers

No Sender, First Receiver Up
Naming Service Receiver1 resolve Sender resolve Sender Sender Sender Receivers Receiver1 Receiver2 bind Receiver1 bind Receiver2 Receiver2
No Sender, Second Receiver Up

Naming Service Sender Sender Receivers Receiver1 Receiver2 Receiver1 Receiver2 Sender resolve Sender resolve Receivers
Receivers Up, then Sender Up

Naming Service Sender Sender Receivers Receiver1 Receiver2 Receiver1 Receiver2 Sender
Receivers and Sender Up, then Third Receiver Up
Receiver3 resolve Sender bind Receiver3 Receiver3 Asynchronous StartUp

Flexible Configuration
Distributor Switching
Sender Distributor Receiver Distributor X X Sender X Receiver-1 Receiver-2 Distributor-1 X X
Sender Switching
Multiple Receivers
Multiple Distributors
Sender Restarting

Further References and Obtaining Software
http://www.dist-systems.bbn.com/tech/QuO/
information about QuO framework
to obtain QuO, send e-mail to quo-help@bbn.com
http://www.cs.wustl.edu/~schmidt/TAO.html
source code for TAO ORB, CORBA A/V service, and AQoSA
UAV application uses TAO 1.1.15 or higher (TAO 1.2 major release is imminent)
further information can be obtained via e-mail from av@oomworks.com
Contact information:
Craig Rodrigues, crodrigu@bbn.com, 1-617-873-4725
Yamuna Krishnamurthy, yamuna@oomworks.com, 1-314-726-1368

NSWC-6-25-01.ppt

by Ronny72 on Jul 15, 2010

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NSWC-6-25-01.ppt Presentation Transcript