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.


Global Multicast Session Parameters

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 62040 see Examples page 2300 bps

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