Visualizing the Global Topology of the MBone
Tamara Munzner, Stanford University
Eric Hoffman, Ipsilon
K. Claffy, NLANR
Bill Fenner, Xerox PARC
We present a case study of visualizing the global topology of the
Internet MBone. The MBone is the Internet's multicast backbone.
Multicast is the most efficient way of distributing data from one
sender to multiple receivers with minimal packet duplication.
Developed and initially deployed by researchers
within the Internet community, the MBone has been extremely
popular for efficient transmission across the Internet
of real-time video and audio streams such as conferences,
meetings, congressional sessions, and NASA shuttle launches.
The MBone, like the Internet itself, grew exponentially with
no central authority. The resulting suboptimal topology is of
growing concern to network providers and the multicast research community.
We create a geographic representation of the tunnel structure as arcs
on a globe by resolving the latitude and longitude of MBone routers.
The interactive 3D maps permit an immediate understanding of the
global structure unavailable from the data in its original form as
lines of text with only hostnames and IP addresses. Data visualization
techniques such as grouping and thresholding allow further analysis of
specific aspects of the MBone topology. We distribute the interactive
3D maps through the World-Wide Web using the VRML file format, thus
allowing network maintainers throughout the world to analyze the
structure more effectively than would be possible with still pictures
or pre-made videos.