7

Internet Weather Map

• Overview of the Internet Weather Map
• Interpreting the Internet Weather Map data

Overview of the Internet Weather Map

The Internet Weather Map statistics screen, in the Configuration utility, provides the following real-time data about the Internet:

• The average round trip time between the local DNS servers on a particular continent and the data centers in your network
• The average completion rate between the local DNS servers on a particular continent and the data centers in your network
• The average number of router hops between the local DNS servers on a particular continent and the data centers in your network

  The data displayed in the Internet Weather Map is based on path data, which is collected when you use a dynamic load balancing mode such as Round Trip Times or Quality of Service. For more information on dynamic load balancing modes, see Using dynamic load balancing modes, on page 8-5 .

To view the Internet Weather Map statistics screen using the Configuration utility

1. Expand the Statistics item in the navigation pane.
2. Click Weather Map.
   The Internet Weather Map Statistics screen opens.
3. For information on working with the Internet Weather Map Statistics screen, view the online help.
   
   

Note: The Internet Weather Map requires the IP classifier, which is not available on the no-crypto 3-DNS. If you are using a no-crypto 3-DNS, the Internet Weather Map shows no valid data.

The round trip time and completion rate data on the Internet Weather Map Statistics screen is based on path data. If you do not have path probing activated, the data on this screen will be stale. The router hops data is based on information collected by the traceroute utility. If you do not allow the 3-DNS to collect hops information, the average router hops data will be stale.

To activate path probing and hops data collection using the Configuration utility

1. Click System in the navigation pane.
   The System - General screen opens.
2. Click Metric Collection on the toolbar.
   The System - Metric Collection screen opens.
3. Check the Allow Probing box.
   The 3-DNS can now collect path information for the data centers in your configuration.
4. Check the Allow Hops box.
   The 3-DNS can now collect router hops information for the data centers in your configuration.
   
   

Working with the Average Round Trip Time table

In the Average Round Trip Time table on the Internet Weather Map Statistics screen, you can view the following information:

• The average round trip time for each data center to each continent
• For each data center, the best average round trip time to the local DNS servers on a particular continent. This value is indicated by bold text within the table.
• For each continent, the best average round trip time from the data centers. This value is indicated by underlined text within the table.
  
  

  If you hold the mouse pointer over the Information button ( ), you can view the following additional information:

• For a particular data center, the number of local DNS servers used to calculate the average round trip time
• For all the local DNS servers that have been probed by a particular data center, the percentage of those local DNS servers that are located on a particular continent
• For all the local DNS servers on a particular continent, the percentage of those local DNS servers that have been probed by a particular data center
  
  

Working with the Average Completion Rate table

In the Average Completion Rate table on the Internet Weather Map Statistics screen, you can view the following information:

• The average completion rate for each data center to each continent
• For each data center, the best average completion rate to the local DNS servers on a particular continent. This value is indicated by bold text within the table.
• For each continent, the best average completion rate from the data centers. This value is indicated by underlined text within the table.
  
  

  If you hold the mouse pointer over the Information button ( ), you can view the following additional information:

• For a particular data center, the number of local DNS servers used to calculate the average completion rate
• For all the local DNS servers that have been probed by a particular data center, the percentage of those local DNS servers that are located on a particular continent
• For all the local DNS servers on a particular continent, the percentage of those local DNS servers that have been probed by a particular data center
  
  

Working with the Average Router Hops table

In the Average Router Hops table on the Internet Weather Map Statistics screen, you can view the following information:

• The average number of router hops between each data center and each continent
• For each data center, the best average number of router hops to the local DNS servers on a particular continent. This value is indicated by bold text within the table.
• For each continent, the best average number of router hops from the data centers. This value is indicated by underlined text within the table.
  
  

  If you hold the mouse pointer over the Information button ( ), you can view the following additional information:

• For a particular data center, the number of local DNS servers used to calculate the average number of router hops
• For all the local DNS servers that have been probed by a particular data center, the percentage of those local DNS servers that are located on a particular continent
• For all the local DNS servers on a particular continent, the percentage of those local DNS servers that have been probed by a particular data center
  
  

Interpreting the Internet Weather Map data

You can use the data in the Internet Weather Map (IWM) to compare performance between data centers. By comparing data center performance over time, you can stage your content in the data centers based on actual usage. The two data points that help you determine which data center has the best performance are the RTT response time (lower is better), and the Completion Rate (higher is better). One easy way to compare data center performance over time is to print a screen shot of the IWM at a certain time every day.

You can also use the IWM data to determine which data center best serves content for which continent. By analyzing which data center provides the best response (usually the lowest RTT and the highest relative completion rate) for a given continent, you can localize your content in the data center that provides the most efficient content delivery.