1. WebSocket Gateway Don McGregor Research Associate MOVES Institute mcgredo@nps.edu

2. Concept Read native IEEE-1278 DIS from the network on which the gateway is located Forward it across a websocket to a web page (typically) or websocket endpoint Decode on the receiving side, often in Javascript 2

3. Websocket Gateway Conops 3 Native Network DIS Websocket Gateway/ Web Server Websocket Gateway/ Web Server Web Page Web Page Web Page Web Page Websocket Endpoint Repeater Websocket Endpoint Repeater Native Network DIS OneSAF, VBS2, etc OneSAF, VBS2, etc

4. Websocket Gateway Now that you know something about gateways you can actually appreciate what the websocket gateway is doing –Enables web application programming for DIS Reads DIS in native binary format, forwards it in binary format to a web page Javascript in the web page decodes the binary format and you write applications in Javascript Note that the format being transmitted across the wire is not JSON—it’s standard binary format DIS The Websocket Gateway is really a bridge that sends native DIS across a new transport mechanism—uses websocket instead of native sockets to send binary DIS 4

5. Websocket Gateway The WSG acts as a websocket server side endpoint via the Jetty web server component kit, which also allows the WSG to act as a webserver –http://www.eclipse.org/jetty/http://www.eclipse.org/jetty/ In Java; reads from the connected ethernet network via the usual sockets. The ethernet network has OneSAF, CXXI, VBS2, etc traffic Sends DIS traffic out to a web page that connects via a websocket Web page typically receives and decodes in Javascript 5

6. WSG Can also set up a “repeater” at a remote network site What if you have simulations at Norfolk and San Diego? You could set up a VPN, or open up ports through the enterprise firewall. Or you could set up a public-facing WSG Security may frown on this, but great for casual simulations 6

7. WSG: Future Do a Node.js implementation? Support for radio/intercom/voice? Support for WebRTC/UDP sockets? Server-side AOIM? Scalability on server side? 7

8. WSG: Advantages Focus of much current programming is web applications, and this enables web programming for DOD M&S No need to define new sim standard standard for JSON Most DOD simulations can gateway to DIS somehow Lots of tools and libraries for Javascript programming Opens possibility of doing area of interest management on the server side Easier deployment Cloud-based simulation? Keep all content on server side Infinitely scalable CPU exists cloud-side—what are the effects of this on M&S? 8

9. WSG: Drawbacks While there are lots of tools for Javascript programming, actual Javascript applications focused on simulations and especially DOD simulations are rare—lots of infrastructure work left Some drawbacks to DIS standard (such as heartbeat) mean HLA simulations may work better with WebLVC; still unknown at this point Threads not supported in Javascript Can get into version hell on the client side with different browsers supporting different features Slower than native performance in Javascript—maybe only able to do small-to-medium sims DIS implementation is proof-of-concept quality 9