# Archipelago Monitor Statistics

Archipelago (Ark): CAIDA's active measurement infrastructure serving the network research community since 2007.
Statistical information for the topology traces taken by this individual Ark monitor is displayed below. See the main statistics page for the full list of monitors

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# fdh-de

Univ. Konstanz
Konstanz, DE (9)

### CCDF of AS path lengths for responding destinations

• percentile 10th 25th 50th 75th 90th Max
AS path length 3 3 4 4 5 9
Use the following link to download the data used to render this graph in ASCII, comma-separated values format here: (CSV output)

### Description

This graph shows the complementary cumulative distribution function (CCDF) of AS path lengths (number of Autonomous Systems) to a destination that responds to probing.

### Motivation

By showing the distribution of AS path lengths to all responding destinations, we can get a sense of how closely connected a monitor is to the 'core' of the Internet.

### Background

The complementary cumulative distribution function shows the fraction of collected data points that are greater than a given value. This is backwards from how percentiles are given, as those show the percentage lower than a given value. On this graph, you would find the 80th percentile at the 0.2 Y value. The AS path length is defined as the number of ASes a probe transits to reach the destination from the Ark monitor. These values are only used when a response has been received from the destination. In other words, incomplete paths are ignored for the purposes of determining AS path length.

### Analysis

Because most AS path lengths fall within a relatively short range, the CCDF graphs will tend to have a sharp drop off around the median. A lower median value of AS path length likely indicates that a monitor is closer to tier 1 or tier 2 providers, as it doesn't have to go through many ASes to reach its destinations.