TULIP
(Trilateration Utility for Locating IP hosts)

Start TULIP	What is TULIP	Lateration	Other ways to locate hosts	Uses of TULIP	Requirements	Landmarks	Problems

What is TULIP

TULIP is a Java application being developed by the MAGGIE-NS team from the National University of Sciences and Technology (NUST) Institute of Information Technology (NIIT) and the Stanford Linear Accelerator Center (SLAC) Internet End-to-end Performance Monitoring (IEPM) project. TULIP's purpose is to geolocate a specified target host (identified by IP name or address) using ping RTT delay measurements to the target from reference landmark hosts whose positions are well known. Knowing the speed of light in fibre or copper (roughly 0.6*c, we use 1ms. is equivalent to 100km), the minimum ping RTT measurement from each landmark site gives a rough estimate of the fibre + copper cable distance of the landmark from the target host. Lateration is applied on these distance estimates to estimate the position of the specified host on the globe.

Lateration

Lateration is the calculation of position information based on distance measurements. Multi-lateration computes the position of an object by measuring its distance from multiple reference positions. Calculating an object's position in two dimensions requires distance measurements from 3 non-collinear points (hence Trilateration).

Other ways to locate a host

Using RTTs: A similar tool to TULIP is Octant from Cornell, which currently works well for the U.S.
Domain Name Services (DNS) may also help in locating a host. The DNS LOC (location) resource record is designed to make this data available. In addition the names of routers often contain their location (e.g. city) so a traceroute may help identify where a host is near.
Autonomous Systems (AS): Given an IP or host name you can use Fixed Orbits to find the relevant AS. Then using a table of AS number to name you can find out more about the AS (e.g. contacts, HQ site etc.)
Whois databases: Examples of sites that provide information from such sources include: IP2location (max 20 requests per day unless sign up), AntiOnline, GeoIP (max 25 requests per day unless sign up), DNSstuff Geolocation, and Hostip.info.
Visual TraceRoute Servers: Example of a site that provides such information is VisualRoute
Geo IP Tool and http://www.ip-address.com/">IP-address.com display location of a selected host/address using Google maps.
Also see NetGeo from CAIDA, which though no longer maintained has many useful links.

If you want to find the great circle distance and know the latitude and longitude coordinates of the two ends then you can use the Movable Type Scripts web page. World Gazeteer provides access to data with lat/longs, cities, countries & populations ( download data). You can also make a name server lookup for a host, or if you don't know the exact name try DomainSurfer. There is also an Atlas of Cyberspace that provides maps and graphic representations of the geographies of the new electronic territories of the Internet, the World-Wide Web and other emerging Cyberspaces and the Corpex sponsored Cyber Geography Research.

Some Uses of Geolocation

If one knows where a host is located then one can choose what content to send to the host, for example what language to use, what local services to recommend etc.
It can be useful for security to pin-point the location of a suspicious host.
It can be used to supplement or verify the information in databases such as Whois, DNS and PingER.
It can be used to help determine from where to get a replicated service.
The pings from multiple landmarks can help identify hosts that have proxies. For example try j.root-servers.net. You will find that for different landmarks there is a response from hosts in Japan, the US, Europe, Brazil etc.

Requirements for TULIP:

Java Web Start must be installed on your system. It requires a configuration file that provides the name and location of each landmark, the URLs for the ping and traceroutes. At SLAC this is kept at /afs/slac/www/comp/net/wan-mon/tulip/Sites.txt.

Landmarks

For hosts in the world at large it is important to have landmarks that enable the host to sit within a triangle of landmarks ^1,2. Thus we are very interested in getting more landmarks that cover the world. The requirement on a landmark is to install a reverse traceroute/ping server (see Traceroute Servers for HENP & ESnet) on a web server at the landmark site. Instructions for downloading and installing the traceroute server are available at http://www.slac.stanford.edu/comp/net/wan-mon/traceroute-srv.html#code. After it installed please let us know so we can add the landmark to the TULIP configuration file (see the bottom of this page for our email addresses).

Problems

If the target host is connected via a geostationary satellite (minimum RTTs > 600ms) then the triangulation will not be accurate.
Some IP names and addresses actually refer to multiple hosts in very different locations. An example are some of the Internet's root name servers. Such hosts will appear to be close to multiple locations, so TULIP will be confused.
Sometimes name service can be very slow causing the pings to timeout. In such a case you can try giving it the IP address instead of the name.
If TULIP complains that it cannot load since another copy is already running, then delete the file C:\Program Files\Mozilla Firefox\pres

References

¹ "An Empirical Evaluation of Landmark Placement. on Internet Coordinate Schemes." Sridhar Srinivasan. Ellen Zegura.
² "Geometric Exploration of the Landmark Selection. Problem." Liying Tang and Mark Crovella

Contacts: Faran Javed Chawla (NIIT) <faran.javed at gmail.com> and Les Cottrell (SLAC) <cottrell at slac.stanford.edu> as part of the MAGGIE-NS team

NUST Institute of IT 2006

TULIP (Trilateration Utility for Locating IP hosts)