Path Analysis

Path Analysis is a visualisation tool for comparing and analysing traceroute data over time. It enables users to identify routing changes, performance degradation, and ASN/IXP transitions by comparing network paths across different time periods.

Overview

Path Analysis helps you understand how network paths evolve by providing:

• Visual comparison of traceroutes across time periods
• Automatic detection of routing changes, ASN transitions, and latency shifts
• Interactive timeline navigation for exploring changes
• Direct comparison mode for before/after analysis

Access Points

Path Analysis is available in two ways:

• Standalone: Access directly at https://atlas.ripe.net/pathanalysis
• Integrated: Currently available on the Probe Detail page under the Results tab (when opening traceroute measurements), it will be rolled out to other parts of the Atlas UI in the coming months.

Path Analysis integrated into the Probe Detail results page

Visual Highlighting System

The tool uses colour-coded indicators to highlight differences between traceroutes:

Colour	Indicates	Description
Yellow	Routing changes	Hops added or removed from the path
Red	ASN/IXP transitions	Different ASN or IXP at the same hop position
Purple	RTT degradation	Performance degradation exceeding thresholds

Colour legend showing yellow (routing), red (ASN), and purple (RTT) highlighting

RTT Highlighting Thresholds

Purple highlighting for RTT changes uses graduated intensity levels to indicate severity:

• Changes must exceed both 10ms and 20% difference to trigger highlighting
• Light purple: 20-40% change
• Medium purple: 40-200% change
• Dark purple: >200% change

Operating Modes

Sequential Mode

Sequential mode allows you to navigate through detected changes within a time window using an interactive timeline.

Sequential mode with timeline showing detected changes

• Each point on the timeline represents a traceroute with detected changes
• Badges on timeline points indicate the types of changes found
• Hover over timeline points to view detailed change information
• Navigate forward and backward through changes using the timeline controls

Comparison Mode

Comparison mode enables direct comparison between two specific time periods.

Comparison mode showing before and after traceroute pairs

• Select exact "before" and "after" time windows
• View one-to-one traceroute pairs side by side
• Useful for investigating specific incidents or maintenance windows

URL Configuration

Path Analysis supports URL parameters for sharing specific views and integrating with other tools.

Data Specification

You must provide one of the following parameter combinations:

Measurement mode (for specific measurement results):

• measurementId — The RIPE Atlas measurement ID
• sourceProbeId — The probe ID to show results from

Anchor pair mode (for anchor-to-anchor measurements):

• sourceAnchor — The source anchor ID
• destinationAnchor — The destination anchor ID
• ipVersion — IP version (4 or 6)

Time Parameters

Sequential mode parameters:

Parameter	Required	Description
center	Yes	Centre point of the time window (accepts milliseconds, seconds, or ISO 8601 format)
window	Yes	Size of the time window in milliseconds
selectedIndex	No	Pre-select a specific timeline index

Comparison mode parameters:

Parameter	Required	Description
sequentialMode	Yes	Must be set to false to enable comparison mode
earlierCenter	Yes	Centre point of the "before" time window
earlierWindow	Yes	Size of the "before" time window in milliseconds
laterCenter	Yes	Centre point of the "after" time window
laterWindow	Yes	Size of the "after" time window in milliseconds

Display Options

Parameter	Required	Default	Description
showHopChanges	No	true	Show/hide hop change highlighting
showRttChanges	No	true	Show/hide RTT change highlighting
showAsnChanges	No	true	Show/hide ASN/IXP change highlighting
title	No	true	Show/hide the title bar
timewindowNav	No	true	Show/hide the time window navigation controls

Example with showRttChanges=false hiding RTT degradation highlighting

Example URLs

Sequential mode with a measurement:

https://atlas.ripe.net/pathanalysis?measurementId=1234567&sourceProbeId=6789&center=1700000000000&window=3600000

Comparison mode with anchors:

https://atlas.ripe.net/pathanalysis?sourceAnchor=100&destinationAnchor=200&ipVersion=4&sequentialMode=false&earlierCenter=1699900000000&earlierWindow=3600000&laterCenter=1700000000000&laterWindow=3600000

Data Export

Path Analysis provides options for exporting data:

• Download JSON (all): Export all traceroutes in the current view
• Download JSON (changes only): Export only traceroutes with detected changes
• Copy traceroute: Copy individual traceroute data for external use

Common Use Cases

Investigating Routing Changes

1. Load a measurement in sequential mode
2. Set a time window around the suspected change
3. Navigate through the timeline to identify when routing changed
4. Look for yellow highlighting indicating hop additions or removals
5. Check red highlighting for ASN or IXP transitions

Analysing Performance Degradation

1. Use comparison mode to compare before and after time periods
2. Look for purple highlighting indicating RTT increases
3. Note the intensity of purple to gauge severity
4. Identify which hops are contributing to increased latency

Monitoring Anchor Connectivity

1. Use anchor pair mode with source and destination anchors
2. Set up regular time windows for monitoring
3. Track changes over time using sequential mode
4. Export data for long-term analysis and reporting