Manual Chapter : Accelerating Requests and Responses with Intelligent Browser Referencing

Applies To:

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BIG-IP AAM

  • 12.1.5, 12.1.4, 12.1.3, 12.1.2, 12.1.1, 12.1.0, 11.6.5, 11.6.4, 11.6.3, 11.6.2, 11.6.1
Manual Chapter

Accelerating Requests and Responses with Intelligent Browser Referencing

Overview: Reducing conditional GET requests with Intelligent Browser Referencing

You can increase the efficiency of the client's web browser's local cache and improve perceived access to your site by enabling the Intelligent Browser Referencing (IBR) feature, which reduces or eliminates requests to your site for relatively static content, such as images and cascading style sheet (CSS) files.

Task summary for reducing conditional GET requests with Intelligent Browser Referencing

Perform these tasks to reduce or eliminate requests to your site for relatively static content by enabling the web browser's cache to serve qualifying content.

Task summary

Configuring Intelligent Browser Referencing advanced settings

You can customize the default prefix, duration of Intelligent Browser Referencing (IBR) lifetime, and duration of adaptive IBR lifetime by specifying advanced settings.
  1. On the Main tab, click Acceleration > Web Application > Applications .
    The Applications List screen opens.
  2. Click the name of an application.
  3. From the General Options list, select Advanced.
  4. Scroll down to the IBR Options area and modify the settings, as necessary.
    1. In the IBR Prefix field, type a string to prepend to links or URLs that are embedded in your web pages.
      Note: If you change the IBR prefix, be sure to test thoroughly to ensure that your application functions properly.
      The default string is ;wa.
    2. In the IBR Default Lifetime field, type a number and select a unit of time from the list to indicate the lifetime of links that match the node.
      The initial default lifetime is 26 Weeks.
    3. In the IBR Adaptive Lifetime field, type a number and select a unit of time from the list to indicate the duration of linked or imported URLs within externally linked CSS files.
      The initial default lifetime is 10 Days.
  5. Click Save.
This specifies the IBR default prefix and duration.

Enabling content assembly on proxies

When you enable content compression or Intelligent Browser Referencing (IBR), you should select the Enable Content Assembly on Proxies check box on the Assembly tab.
  1. On the Main tab, click Acceleration > Web Application > Policies .
    The Policies screen displays a list of existing acceleration policies.
  2. Click the name of a user-defined acceleration policy.
  3. Click a node in the Policy Tree.
  4. From the Matching Rules menu, choose Acceleration Rules.
  5. On the menu bar, click Assembly.
    The screen refreshes to show assembly options.
  6. Select the Enable Content Assembly on Proxies check box.
    Note: When selected (enabled), the BIG-IP system requests gzip-encoded or deflate-encoded content from the origin web server. The origin web server complies only if it supports the compression mode; otherwise, the origin web server provides uncompressed content.
  7. Click Save.
  8. Publish the acceleration policy.
    1. Click Publish.
    2. In the Comment field, type a description.
    3. Click Publish Now.
The BIG-IP system can compress content as required, and manage content by using IBR, even if the content is not served from the BIG-IP system's cache.

Enabling Intelligent Browser Referencing

The following prerequisites apply to enable Intelligent Browser Referencing (IBR) for a specific node.

  • Specific variation rules must be configured with ordinals Method, Cookie, User Agent, Referrer, Header, and Client IP using a Values Define setting of Same Content. Variation rules cannot be defined for the node using a Values Define setting of Different Content. For example, if the link matches to a variation rule that identifies a cookie as being significant for content, the BIG-IP system cannot apply the IBR feature.
  • The Always proxy requests for this node option is not selected.
  • No Proxy Override Rules are defined for the node.
You can increase the efficiency of the client's web browser's local cache, and improve perceived access to your site by enabling IBR, which reduces or eliminates requests to your site for relatively static content, such as images and style sheet (CSS) files.
Note: When an object is matched to a rule in which the IBR feature is enabled, the BIG-IP system ignores the client cache minimum age settings for that object. However, the HTML page, into which those objects are loaded, honors all client cache minimum age settings.
  1. On the Main tab, click Acceleration > Web Application > Policies .
    The Policies screen displays a list of existing acceleration policies.
  2. Click the name of a user-defined acceleration policy.
  3. Click a node in the Policy Tree.
  4. From the Matching Rules menu, choose Acceleration Rules.
  5. On the menu bar, click Assembly.
    The screen refreshes to show assembly options.
  6. Select one or both of the following settings, as applicable.
    Option Description
    Enable Intelligent Browser Referencing To Specifies the system modifies external links that match the node with unique subdomains.
    Enable Intelligent Browser Referencing Within Specifies the system modifies URLs within a CSS file that is linked or imported into an HTML document.
    Important: Setting any of the following Variation rule parameters to Different Content disables Intelligent Browser Referencing (IBR) and MultiConnect to the policy node. You must set these parameters to Same Content to enable IBR and MultiConnect to the policy node.
    • Method
    • Cookie
    • User Agent
    • Referrer
    • Header
    • Client IP
  7. Click Save.
  8. Publish the acceleration policy.
    1. Click Publish.
    2. In the Comment field, type a description.
    3. Click Publish Now.
The BIG-IP system applies IBR to the policy node for the linked object in the HTML page or within the externally linked CSS file, typically, an image, style sheet, or JavaScript document.

Adjusting the adaptive Intelligent Browser Referencing lifetime

Before you can adjust the adaptive IBR lifetime, the Enable Intelligent Browser Referencing Within check box must be selected for a policy node used within an application, providing Intelligent Browser Referencing (IBR) for embedded image links within externally linked cascading style sheet (CSS) files.
You can adjust the IBR Adaptive Lifetime setting to the shortest lifetime of an image defined within externally linked CSS files, enabling assembly of linked image files before all of the image files are cached, and enabling the embedded image files to refresh before a client uses stale image files from a browser's cache.
  1. On the Main tab, click Acceleration > Web Application > Applications .
    The Applications List screen opens.
  2. Click the name of an application.
  3. From the General Options list, select Advanced.
    The IBR Options area appears.
  4. In the IBR Adaptive Lifetime field, type a number and select a unit of time in the list to indicate the duration of linked or imported URLs within externally linked CSS files.
    The initial default lifetime is 10 Days.
  5. Click Save.
This specifies the shortest lifetime of an image defined within externally linked CSS files, enabling assembly of linked image files before all of the image files are cached, and enabling the embedded image files to refresh before a client uses stale image files from a browser's cache.

Implementation result

BIG-IP® acceleration reduces or eliminates requests to your site for relatively static content, such as images and style sheet (CSS) files, by enabling the web browser's cache to serve qualifying content.