Use bandwidth measurement to learn the differences in your end users' experience and adjust your delivery to meet their needs. Knowing your end users' bandwidth can help control data center costs and resource consumption as well.

Bandwidth measurement is an option that's enabled for a short period of time—usually a few days to test the impact of a new release or feature—and then it's disabled. It's also common to run a sample of your end users rather than running it against all of your end users.

Set up a bandwidth test to filter page load times and other mPulse data by bandwidth range. This can help you to better recognize how your end users' experiences might vary.

A bandwidth test setup includes test images of varying sizes that you place on either the origin or a CDN. Each time a bandwidth test runs, mPulse downloads the images from smallest to largest. mPulse measures page load times until all of the images load—or until an image exceeds a predetermined time, at which point the test stops. In either case, mPulse calculates bandwidth from the accumulated data.

Where you place the mPulse test images depends on what you want to measure.

Consider the following:

• When placing the test images on your origin, the images are not cached on the client. mPulse uses cache-busting query string parameters to force an image reload. This ensures that mPulse tests the bandwidth to your origin and not the bandwidth to a local cache. Also, browsers ignore Cache-Control, Expires, and Last-Modified headers sent with the image. To make sure that the test is accurate, it's best to send as few headers as possible when serving these images.

• When placing the test images on a CDN, the CDN sends a call back to your origin server each time an end user makes a requests. This may not be the best use of your CDN. Configuring your CDN to ignore query string parameters for these images can be an option (see Set up caching for bandwidth images in Property Manager).

Set up a bandwidth test

Run a bandwidth test against a sample of your end users to see their bandwidth distribution.

For more information on mPulse bandwidth testing, visit Community.

How to

1. In mPulse, click Central.

2. At the bottom of the left pane, click Resources to open the Resources page.

3. Under Downloads, click Bandwidth Testing Images to download the images.zip file.

4. Unzip the file and upload the images to a web accessible location on your origin server (for example, http://www.mydomain.com/mpulse/images/) or CDN (see Set up caching for bandwidth images in Property Manager).

5. In mPulse, click Central.

6. In the left pane, click Apps, then double-click the app that you want to use for your test.

7. Click General.

8. Select the Enable bandwidth test checkbox.

9. In the Images location field, enter the URL where you uploaded the bandwidth images, as shown in this example. Make sure to include the trailing backslash for the folder name.

10. In the Sampling Percentage field, enter the sampling percentage if you want. mPulse enforces the value as a percentage of your total sessions. When tracking large sites, you can adjust the percentage of the population as the test runs. This can help you to understand how to control costs and resource consumption.

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Caution

When applying a sample rate, there are data usage implications that you should be aware. A single bandwidth test run can result in data transfers totaling about 4 megabytes. This can be a burden for mobile users with limited data plans. For example, if you run this test against a million of your end users, that's about 40 terabytes of data moving across your network.

11. To exclude mobile users from the test, select the Disable Bandwidth Testing for Mobile User-Agents checkbox.

Next steps

Use the Bandwidth Blocks pie chart to see your end users' bandwidth distribution.

Set up caching for bandwidth images in Property Manager

If ​Akamai​ delivers your traffic, use the mPulse bandwidth images to measure the bandwidth between your end users and the ​Akamai​ edge server.

To set up caching for your mPulse bandwidth test images, configure these behaviors in your mPulse enabled property:

• Cache Key Query Parameters

• Caching

• Downstream Cacheability

How to

1. Go to ☰ > CDN > Properties.

2. Create a new version of your mPulse-enabled property configuration. For details, see Versions and Versioning in Property Manager help.

3. In the Rules section of the property, click Add Rule.

4. In the right pane, give the rule a name (for example, Cache Bandwidth Images), then click Insert Rule.

5. In the Criteria section, click Add Match, select Path, select matches one of, then enter the location of the bandwidth images on the ​Akamai​ network, as shown in this example.

6. In the Behaviors section, click Add Behavior to open the Add a Behavior for this Rule dialog.

7. From the available behaviors list, select Cache Key Query Parameters, then click Insert Behavior.

8. From the Behavior menu, select Exclude all parameters, as shown in this example.

9. Click Add Behavior.

10. From the available behaviors list, select Caching, then click Insert Behavior.

11. Set the Max-age to 365 days, as shown in this example.

12. Click Add Behavior.

13. From the available behaviors list, select Downstream Cacheability, then click Insert Behavior.

14. From the Caching Option menu, select Don't allow caching (bust), as shown in this example.

15. Save the configuration.

16. Activate the property on the ​Akamai​ staging network.

17. After the property is active on staging, test your property configuration to make sure your website is working as expected.

18. From mPulse, open a dashboard (for example, the Summary dashboard) and make sure that the page views count is increasing.

19. After you test your property configuration on staging and check the page views in mPulse, activate the tested property version on the production network.

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Note

An initial mPulse property configuration can take an average of 15 minutes to deploy to the edge servers. This is based on the amount of traffic being sent, and time to populate the data in the portal. If you experience delays greater than 4 hours, contact your account representative for assistance.

20. Once your property configuration is activated on the production network, it'll be several minutes before mPulse receives your data beacons.

Next steps

Log in to mPulse, and use the Bandwidth Blocks pie chart to see your end users' bandwidth distribution.