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J AVELIN. Michael D. Myjak Vice President & CTO The Virtual Workshop, Inc. P.O. Box 98 Titusville, FL 32781 <mmyjak@virtualworkshop.com>. Keith Briggs President iMT, Inc. P.O. Box 4380 Mountain View, CA 94040 <keith@imtinc.com>. J AVELIN.
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JAVELIN Michael D. Myjak Vice President & CTO The Virtual Workshop, Inc. P.O. Box 98 Titusville, FL 32781 <mmyjak@virtualworkshop.com> Keith Briggs President iMT, Inc. P.O. Box 4380 Mountain View, CA 94040 <keith@imtinc.com>
JAVELIN Java Virtual Environment Layered Infrastructure & the Java Real-Time RTI
JAVELIN - Overview • Introduction … (What it is) • HLA Products… (Who we are) • Architecture • Hierarchical, Object Oriented Design • Networking Approach • Low Latency Performance • Virtual Reality Transfer Protocol • Real-Time Transfer Protocol • Open Architecture
JAVELIN - Revolutionary New Technology • Requirements driven • Performance in Real-Time Environments • Platform Independence • Open Architecture and 100% Object Oriented Design • JAVELIN supports • streaming protocols, real-time communications and embedded network management for embedded systems through web-based applications • Technology enabled • Java Native Application • Embraces OSI Initiative of the ISO and IETF Standards • Hierarchical Design Approach
HLA Products… Who we are • Focused on the commercialization of HLA technologies • Defense and Commercial Applications • Education, Training, Research and Development • Combines iMT and TVW resources to achieve success! • Principles in HLA, SISO, IETF, Web3D (VRML) and Java communities • Past and Present SISO RTI&C chairs, RTI Interop Chair, SAC Vice Chair, HLA SDG AR, RPR FOM DT, RD&E Forum Vice Chair and Chair of the IETF Large Scale Multicast Application (LSMA) Working Group • Strong community participation provides insight into requirements and solutions • Founders have over 70 years of combined experience! • Obtained significant investment to build JAVELIN
JAVELIN Architecture Architecture
Hierarchical Design • From the onset, JAVELIN was designed to be Scaleable and Extensible • Specifically Designed to Support Distributed Hierarchical Federations • JAVELIN’s Hierarchical design draws on years of experience dealing with scaling issues on the level of the Internet • Hierarchical Design With Locally Distributed State Implementation • Planned Intra Federation and Inter Federate Component Support • Well-Defined “On The Wire” protocol
Application Virtual Reality Transfer Protocol AOIM Network Manager Presentation Real-Time Control Protocol Real-Time Protocol Real-Time Streaming Protocol Session Transport Network Data Link Hardware JAVELIN Organization JVM AVE Java Real-Time RTI irtual nvironment JAVELIN ayered nfrastruvture UDP, TCP, SNMP, RSVP, etc. Internet Protocol (IP) Ethernet, ATM, FDDI, etc... Cards, Cables, Computers …
SUN SGI IBM Linux Linux Simple Network • A local net example with a few federates Simulation nodes PC NT RTI Manager Token also manages Local Net
Short Distance Peers • Two locally connected network segments Distributed JAVELIN Broker Simulation nodes 1-5 Segment 2 Segment 1 RTI Manager Token Local Net Manager Token JAVELIN Broker
Long Distance Peers • Three local network segments connected via Interconnecting Hub Segment 3 Local Routers Simulation nodes 1-5 Interconnecting Hub Segment 2 Segment 1 RTI Manager Token Local Net Manager Token JAVELINBroker
Large Scale Network • Example using a generic WAN connected via long haul Internet, Private Intranet, etc. LAN 3 WAN Border Router/Gateway Simulation nodes 1-5 LAN 2 WAN the Cloud RTI Manager Token Local Net Manager Token JAVELIN Broker LAN 1
Heterogeneous Architecture • JAVELIN supports multiple, non-congruent architecture systems, end-to-end! LAN 3 Massively Parallel Architectures Shared Memory Systems LAN 1 LAN 2 RTI Manager Token Local Net Manager Token JAVELIN Broker
JAVELIN Architecture Networking Approach
JAVELIN Networking • Platform and Network Independence • Maximum throughput with absolutely minimal latency (<5ms). • Special Support for Streaming Data • Embedded Management Services • Federate and federation "cut-through" functionality • Integration with the Web!
Application Layer Presentation Layer Session Layer Transport Layer Internet Layer Data Link Layer Hardware Layer Heterogeneous Interoperability ref: IEEE 1278.2-1995 - Interoperability through the ISO 7-layer model User’s Application Protocol Layers • Our foundation: The OSI Model...
HLA is Not Quite There… Yet! • The current HLA specification doesn’t guarantee complete interoperability (ref: 99s-SIW-140) • HLA has been shown to work in well-defined, homogeneous, and often monolithic environments with vendor and platform dependencies • The Java VM breaks through this ideology • Allows system independent functionality, end-to-end, in a heterogeneous environment • Still, the Java Real-Time RTI isn’t complete • A Standard communications protocol between RTI components is a necessary underlayment
JAVELIN Architecture Virtual Reality Transfer Protocol
JAVELIN Application Layer • We placed HLA RTI at the Application Layer... • This approach provides a clear, concise and unambiguous Interface to HLA Federates from the Java Virtual Machine • Complies with HLA Federate Interface Specification (Draft IEEE 1516 v3) • Application Layer Protocols define two interfaces: • To the “User Application” Above • To the Next Layer Protocol Below
JAVELIN Presentation Layer • Virtual Reality Transfer Protocol • light-weight entity interactions • e.g. HLA Attribute / Value pair Updates • network pointers • e.g. Uniform Resource Locators (URLs) • heavy-weight objects • e.g. HLA RTI services and Requests • real-time streams • e.g. Mbone audio / video
JAVELIN Presentation Layer (con’t) • VRTP also incorporates other key features • Embedded Network Management • Internal to each JAVELIN installation • Based on the Simple Network Management Protocol (SNMP) • Internal Area of Interest Management • Controls Partitioning of Network Traffic • Tightly Coupled with the JAVA Real-Time RTI for enhanced HLA DDM support
JAVELIN Session Layer • VRTP is supported by the Real-Time Transfer Protocol (RTP) • Lightweight RTP header, Includes: • Sequence Numbers • Time Stamps • Specialized control for Multiple Streams • Real-Time Streaming Protocol • Real-Time Feedback is also provided • Real-Time Control Protocol
JAVELIN Session Layer (con’t) • VRTP provides: • 3D scene specification for the Web • Supported by the Real-Time Transfer Protocol (RTP) • VRML 2.0 specification is done • VRML NG specification is under way! • Behaviors: • Java, JavaScript, and more to come • Repositories • www.stl.nps.navy.mil/~brutzman/vrtp • http://www.web3d.org/
Transport and Network Layers • Conforms to existing and emerging standards • Open Systems Interconnect (OSI) • High Level Architecture (HLA) • Virtual Reality Transfer Protocol (VRTP) • Real-Time Protocol (RTP) Including: • Real-Time control protocol (RTCP) • Multi Stream Support • Simple Network Management Protocol (SNMP) • Network Time Protocol (NTP) • Bandwidth Reservation Protocol (RSVP) • and the Internet Suite of Protocols • (e.g., IP, UDP, TCP, IPmc, etc.)
Streaming Communications Support • Future Networked Applications… • Streaming Audio/Video • Virtual Teleconferencing • Internet Collaboration • Distance Learning and Adult Education • Existing Example: The Multicast Backbone… • Is active, and WorksToday! • Applications exist, are in use, and are built into IPv6!
VR Web • What does desktop look like? • Client • looking at someone else’s world • Server • showing others your world • Peer • scaleable behavior and interactions • “everything just works”
VR Web • What does desktop look like? • Client • looking at someone else’s world • Server • showing others your world • Peer • scalable behavior interactions • “everything just works” means monitoring what the heck is going on out there!
Open Systems Additions • OSI structure provides for natural extensibility • Defined interlayer APIs • Tried and tested architecture • JAVELIN’s object oriented structure permits modification of a single layer • Java Object Interfaces define structure and requirements • Methods can be extended and modified within structure
JAVELIN Architecture Low Latency Performance
Low Latency Requirements • Real-time applications require minimal overall (i.e., End-to-End) system latency • ~2,000 RTP updates per second • JAVELIN’s component infrastructure minimizes overall system latency • Performance Comparable to DIS • RTP Time Stamp and Sequence Numbers • Bi-level Ordering on every datum and across streams • Scaleable O(LogN) Performance • Improves consistency • Promotes deterministic results
Required (optional) Attribute Data specified in attrHandleMap, Fixed Length noted in FED file High Throughput - Low Overhead Current Attribute Value Update Serial # Object ID AttrMap Data[0] Data [1] Length D[n] Data [n] Tag Int Int 1+ Bytes Int Int Bytes [ ] Bytes [ ] Bytes [ ]
High Throughput - Low Overhead • 9 Bytes (Minimum) of RTI Overhead • Plus 1 byte for each variable length Attribute Current Attribute Value Update Serial # Object ID AttrMap Data[0] Data [1] Length D[n] Data [n] Tag Int Int 1+ Bytes Int Int Bytes [ ] Bytes [ ] Bytes [ ]
Single Lookup Design • At the lowest level • the JAVA Real-Time RTI state data is reflected to every RTI instance • Improves Performance • Lowers End-to-End Latency • Through JAVELIN’s hierarchical design • RTI state data is segmented and controlled efficiently! • Single lookups are all that is required to resolve data distribution
State Reliable Protocol • RTI state data (e.g., control, data) is transmitted reliably • Low latency best effort transmission • Capitalizes on high reliability, low latency in local subnets • Currently prototyping several state reliable approaches • Forward Error Correcting • Selective Retransmission • Reliable Multicast • NACK-based) • w/ Congestion control
Consistent Multi-threaded Design • Low latency requires a multi-threaded implementation • Platform independent multi-threaded design is not feasible with current “C” based environments • Java provides a consistent multi-threaded supportable architecture • Update/Reflect implemented in separate high priority threads to minimize End-to-End latency
Java Performance • Contrary to popular myth, JAVA is Not a bottleneck • Java Hot Spot Virtual Machine (VM) performance promises to match C++ efficiency in many areas • Java v2 JVM (SUN native) Excels! • RTI does not require graphics support • the current bottleneck with Java • JAVELIN prototypes have performed well using currently available JRE (v1.1.b)
Cross Platform Capabilities • Commercial support of JAVELIN across disparate platforms would not be possible without JAVA • Porting costs are greatly reduced • Similarly, maintenance costs are lower • Big Win - Reduced development time • No more Big/Little “endian” problems • No word size inconsistency
Programming Efficiency • Substantial increase in programming efficiency • Improved syntax / readability • Standard support for arrays, hash tables • Established documentation standards • Pure object language • High level language support for system operations (networking, etc.)
Embedded Solutions • Java is rapidly becoming the standard for embedded solutions • Java is supported by all of the major embedded operating systems • Embedded Java and Personal Java provide optimized environments for embedded applications • Porting to the embedded real-time OS is simply easier to accomplish!
A Living Language • Java is a “living language” • Java is evolving with the web and with new commercial solutions • New enhancements are being developed to support: • Improved distributed programming • And new graphics standards - • Web3D (VRML), Java 3-D, etc • The standardization process for “C” and “C++” limits their market responsiveness
A Natural for Web Programming • The features required for web programming are native in Java • Networking support • HTML processing • Web based applets • Portability • Java IS the standard for web based programming today • And With GOOD REASON!
JAVELIN An Open Architecture Solution
Source Code Availability • HLA Products will license the source code for JAVA Real Time RTI • Source code availability makes sense • Reduced development time • Users benefit from all partners • The Virtual Reality Transfer Protocol is similarly available in Open Source • VRTP Working group recently Chartered under Web3D Consortium • Its simply the right thing to do! • LINUX, Netscape, GNU, etc.
Web-JAVELIN The Future Learning Solution
Javelin Michael D. Myjak Sean T. Sharp Vice President & CTO The Virtual Workshop, Inc. P.O. Box 98 Titusville, FL 32781 <mmyjak@virtualworkshop.com> Keith Briggs President iMT, Inc. P.O. Box 4380 Mountain View, CA 94040 <keith@imtinc.com>