DIS-Java-VRML: Multicast Backbone (MBone) Testing

Distributed Interactive Simulation
DIS-Java-VRML Working Group

click for Dis-Java-VRML home page

Multicast Backbone (MBone) Testing

Currently NPS is working with MBone connectivity via newly reconfigured
Defense Research and Education Network (DREN) connections.

Problem reports are welcome.

Introduction

We are beginning to experiment with global DIS exercises via the Multicast Backbone (MBone). This is pretty cool! It also requires serious caution.
You can test your local MBone-DIS connectivity using the Examples.
Additional test programs are available in the testing package, shown in the Software Reference.
You can learn more about this topic via the Multicast Networking section of the Annotated References page.

Global Multicast Session Parameters

The globally advertised sdr session name is dis-java-vrml. A copy of the sdr session directory cache file appears as sdrCacheDJVSession.txt, along with related inscrutable cache files archived in the sdr/cache/ subdirectory.

Channel	Time-to-live (TTL) scope	Stream	Multicast address	Port	Application	Expected bandwidth

Connectivity check One or two entities, global (MBone-wide), 24 hours/day, each providing 144-byte ESPDU/second streams	Connectivity check is the default DIS PDU listening channel, fed only by devo.cs.nps.navy.mil (131.120.7.xxx) Clients use it to check for direct multicast backbone (or multicast relay) connectivity to clients. This is also the channel used for local (low ttl) testing of the second entity. Please do not use higher ttl values when sending on this channel! We want to keep bandwidth low enough for modem links.
	127 (global)	DIS Entity State PDUs	224.2.181.145	62040	see Examples page	2300 bps

Coordination	The Coordination channel provides MBone audio/video/text tools for coordinating all DIS exercises.
	127 (global)	Audio	224.2.168.160	20074	rat	64 Kbps
		Video	224.2.220.5	56414	vic	64 Kbps each
		Whiteboard	224.2.167.219	48947	wb	low
Text NTE	224.2.246.18	58491	nt	low

dis-java-vrml testing open to all entities 24 hours/day low or high bitrates	127 (global)	DIS Entity State PDUs	-not yet-	-not yet-	see Examples page	to be determined
	dis-java-vrml testing will be for unrestricted sending, receiving and experimentation. Developing sensible test conventions requires further dialog and careful experimentation. Please ensure that your streams eventually time out and stop! We have built timeout limits into the libraries, you should not disable them.

July 6 2000 (official NPS disclaimer)
URL: www.web3D.org/WorkingGroups/vrtp/dis-java-vrml/MBoneTesting.html
feedback: brutzman@nps.navy.mil & mcgredo@cs.nps.navy.mil