HLA Project Overview

ACIMS LabPrepared by: Saurabh Mittal

To Start with…

• Basic ideas on– Designing network environments with

common parameters (e.g. mean distance, probability of connection, quantized or periodic updates, etx.)

– Modeling various components within these networks

• Preliminary design of router completed

• Basic tests conducted(eg. Ensuring packet routing etx..)

DEVS Simulation Layer(nodes and links being simulated as per DEVS Formalism)

Experimental Frame Layer

Network Modeling Layer

Routing Sub-layer

Topology Sub-layer

Area encompassing components designedusing DEVS Formalism

Topology Designer

VisualizerParameter Controller /

Evaluator Traffic Generator

Layered Architectural Framework

DEVS Modeling & Simulation HLA Network Framework

Development of DEVS:• Modeling API for components in Application

Layer• Routers• Links• Message Passing and other specialized features

related to Application Layer components

System Entity Structure (SES) for Net-Framework

Network Node

Improvise Router (network) Node for HLA implementation

• Develop the router node as shown below and create a network

Payload Traffic

GeneratorRTI

Ambassador

updates

Updates to specific destinations

Routing/Lookup Table

Real-time Routing Engine

Forwarding Engine

Routing Capability Inside every network Node (taken form earlier Version of simulation-based Router)

Message Passing to be implemented

Traffic generatorGenerating packetsOf different classes

M/M/1 queuing system that routes packets based on the information from the forwarding engine. The queuing system characterizes the RTI capabilities

HLA / RTI Implementation

• Centralized and De-centralized versions of network HLA/RTI under consideration

• Different experiments devised to gather information about– Thruput– Network delay– Link utilization

• Transducers being implemented within components (links+routers) to gather individual data in an automated manner.

Conceptual Centralized HLA/RTI network

• Network components– Centralized RTI Executive node

• Receives packets being published• Broadcasts packets being subscribed

– HLA Router• Generates traffic containing packets of different

‘classes’

– Links

Centralized HLA/RTI Network

HLA Router Network

HLA Router 1

HLA Router 2

HLA Router n

RTI EXECUTIVE RTI Executive - a part of the Network - routers publish messages of different ‘classes’ to RTI - broadcasts messages to every other node - those subscribed to particular ‘class’ of messages, attend to it, others ignore

Metrics - end-to-end Delay - average link utilization - thruput - queuing time at RTIExec

‘RouterNode’

‘HLA Router’

‘HLA Router’

‘HLA Router’

DEVS Demowith RTI Executive

Example Topology being modeledRun networkHLAwithRTIExec.java

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RTI Executive

HLARouter

DEVS Network in simView

RTI Exec Router links

RTI Exec links

HLA Routers

Publish-Subscribe functionality

• Each federate– Publishes packets to ‘classes’– Subscribes to particular ‘classes’

If there is RTI Executive present• Packets are published to destination RTI Exec• Packets are broadcasted to other federates thru it• Packets can be multicasted to only those federates who subscribe to those

classes

If there in NO RTI Executive present• Point-to-point network• Packets generated to specific destinations

public class Publish extends entity {

///stores classNames in string format

private ArrayList classes; private ArrayList classesString; private ArrayList classesDouble; public Publish() public Publish(String name) public void publishMsgOfClass(String msgClass) public void publishMsgOfClasses(ArrayList classes_) public int getPublishedClassCount() public String getClass(int i) public boolean isClassOfMsgPresent(String msgClass) public void removePublishedClass(String msgClass) }

Similar is the ‘Subscribe’ class

Benefits:•Can communicate in more than One data-type as opposed to just ‘Strings’Better functionality and encapsulationby creating a Publish or Subscribe object

DEMO 1

Run networkHLAwithRTIExec.java main function

• Visualization of constructed DEVS Network in real-time manner

. • Adjusting of network

parameters for observing behavior of the network

• Modular GUI development and GUI created at run-time during the time the network gets created

• EASY to IMAGINE what you want to achieve with your network

LINK PANEL

ROUTER PANEL

Real-time Simulation

Controller

DEMO 2

• Attractive GUI• Change dynamically,

– Number of nodes

– Distance between nodes

– Link Properties

– Connection-density

• Integrate with Demo 2 in progress

• Run ListSelect.java main function

FAST Mode DEVS simulation inside devsNetworkHLA.java

public void simulate(){ s.s("inside devsNetworkHla.java simulate()"); coordinator c = new coordinator(this); c.initialize(); c.simulate(1000); }

Snapshot of OUTPUT

PACKET RECEIVED AT : HLA Router_node_8Packet_from_0_to_8_cost_5.0_type_0_Class_b_nextHop_8------PACKET HAS REACHED ITS DESTINATION with the info: I am NOT SUBSCRIBED TO THIS CLASS: Class b ...ignoringPacket_from_0_to_8_cost_5.0_type_0_Class_b_nextHop_8------PACKET RECEIVED AT : HLA Router_node_3Packet_from_8_to_3_cost_5.0_type_0_Class_d_nextHop_3------PACKET HAS REACHED ITS DESTINATION with the info: I am NOT SUBSCRIBED TO THIS CLASS: Class c ...ignoringPacket_from_1_to_0_cost_5.0_type_0_Class_c_nextHop_0------PACKET HAS REACHED ITS DESTINATION with the info: I am NOT SUBSCRIBED TO THIS CLASS: Class b ...ignoringPacket_from_0_to_8_cost_5.0_type_0_Class_b_nextHop_8------

PACKET HAS REACHED ITS DESTINATION with the info: I am NOT SUBSCRIBED TO THIS CLASS: Class d ...ignoringPacket_from_1_to_3_cost_5.0_type_0_Class_d_nextHop_3------

Terminated Normally at ITERATION 1001 ,time: 2.191101580114225

Topology Designer

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HLA Routers connected in P2P network and communicating without RTI Executive

HLA Routers connected in P2P network and communicating THRU RTI Executive

Experiment No. 1 Experiment No. 2

Each Federate publishing 3 types of packets and subscribed to 3 different class of packets. The receiver federate attends only to the subscribed packets and ignores other packets.

Simulated Topological setup

P2P Run Time to Stabilize Thruput of Network

INCREASE in Thruput

Plot of Avg Thruput v/s TimeAvg Thruput v/s Time

Further INCREASE in

Thruput

Time to Stabilize

after updating

RTI Delay

Plot of Link Max Q length v/s TimeLink Max Q length v/s Time Plot of

Latency Max v/s Latency Max v/s TimeTime

Increase in Queue Lengths of Network due to Increase in

Load

UPDATED Load

UPDATED Link Capacities Packets in Links

Packets in Routers

Centralized HLA: Broadcast ModeT= 4.461 sec

RESPONSE Time

Thruput Stabilization for

RTI Links

SNAPSHOTTime

Packets in Links

Resulting Q Length for RTI Length during Stabilization

Centralized HLA-Multicast mode

SNAPSHOTTime

Thruput Stabilization for

RTI Links

Resulting Q Length for RTI Length during Stabilization

Link CapacityReduced to

accommodate Stabilized load

RESPONSE Time

Other Simulation Experiments

• Various other case studies were conducted– Benchmarking and Tuning of this DEVS

model based on reported results for RTI latency

• Details can be looked in the Project report.

• Thanks for your Attention !!!