The Map Diff tool locates the maps closest to the first and second dates you specify, and reports changes between the two maps for the given domain.

Map Diff enables you to analyze the differences in nameserver-to-datacenter maps for two points in time, and reports the top differences between them for each data center, in terms of AS ("Autonomous System"‚ÄĒthat is, Internet network provider) and country of origin.

Map Diff reports are particularly useful if you notice a traffic shift and want to understand what shifted. For example, let's say you notice that traffic volume dropped sharply in your Atlanta datacenter at 5:00 p.m., but traffic returned to normal levels three hours later. Using Map Diff, you can quickly determine which traffic was affected by the change.

To obtain this information, enter the start and end time of the traffic shift. Map Diff compares maps made at the two times, and shows which traffic targets had the greatest traffic shifts from one map to the other, and which ASs and countries shifted the most within each traffic target. The traffic shifts are reported in two directions: traffic flowing from the earlier time to the later time, and vice-versa. Map Diff reports only the five ASs and countries with the most change in each traffic target, in each direction. Every Performance property in a domain is analyzed.

Submit a request

Learn how to submit a request in the Map Diff tool.

  1. Go to ‚ėį > SUPPORT > Edge Diagnostics.
  2. In the side menu, select > Map Diff.
  3. Select target Domain.
  4. Set First Map date and time.
  5. Set Second Map date and time.
  6. Click Compare Maps.

Filtered Map Diff

After you create a basic report on a traffic shift, you can select the name of an AS or country. This enables you to see a comparison of the performance metrics at each time, which help explain why traffic shifts occurred.


Suppose you wanted to analyze a mapping shift in the domain storage that occurred between 7:00 p.m. GMT on February 22, 2010 and 3:00 p.m. GMT on February 23, 2010. When you enter those times in the Portal, Map Diff locates the maps that were made closest to those times, and compares them.

How to interpret a traffic shift report

A positive traffic change is often accompanied by an improved score, and a negative change by a lower score. The Geo score represents distance values from on-net agents. Ping score represents the average network response time for all on-net agents in the select AS for the select data center.

Map Diff is best suited to analyze known issues, rather than to search for potential mapping problems. Also, keep in mind that Map Diff samples only the name servers that ‚ÄčAkamai‚Äč mapping system believes have relatively heavy traffic. Thus, this tool does not generate data on every possible mapping shift, just the most critical ones.