Skip to Content
[CAIDA - Center for Applied Internet Data Analysis logo]
Center for Applied Internet Data Analysis
Internet Atlas Gallery

Layout Showing the Major ISPs

Bill Cheswick, Bell Labs and Hal Burch, CMU
Lucent Technologies Bell Labs Innovations
Carnegie Mellon University (CMU) Computer Science Dept.
URL: http://www.cs.bell-labs.com/who/ches/map/gallery/index.html

Visualization ThumbnailAbout the Data
Data Sources:
(Source1): All registered target networks from Merit's routing arbiter database at ftp://ftp.merit.edu/routing.arbiter/radb/dbase/.
(Source2) Full network scan (this graph uses data from 28 June 1999). First, possible host names are generated for all possible destinations obtained from the routing arbiter database (Source1). Heuristics are used to pick an IP address that is likely to be in use. A slow host scan over time is then made until a responsive host IP address is found. Finally, a set of UDP probe packets are sent to each of these hosts, where successive packets increment TTL by 1 until a) the host is reached, b) an ICMP error is returned, or c) a hop is reached that doesn't respond to several pings.
(Source3) Daily DNS reverse PTR lookups on any new addresses discovered (approximately 5,000/day).
Data Specification:
(Data1) Path database: Simple text format containing one line per target network. First field is the target network in familiar form: 135.104.0.0/16. Remaining fields are in the form: name=[date:]value, and are used to track:
  • Path: a comma-separated list of IP numbers, followed by a status code unless the path successfully reached the target.
  • Probe Date: Date of most recent probe
  • Target: date of first probe and IP address of responsive host
  • Whiner: date and email address of person requesting that this network not be scanned

(Data2) Label Database: Simple text format. One entry per line containing an IP number, a label, and the date it was collected, separated by white space.
Data Aggregation:
(Aggregate1): Various groupings of IP addresses can be derived. For example, matching IP address octets to top-level domain can show approximate country location, or, in this example, IP address octets are matched to second-level domain to show ISP names.
Data Filters:
(Filter1): Edges may be removed.
(Filter2): Data may be reduced to show only shortest paths.
Full-Size Visualization Back
  Last Modified: Tue Oct-13-2020 22:21:40 UTC
  Page URL: https://www.caida.org/projects/internetatlas/gallery/ches/data.xml