Manual Chapter : Establishing Additional TCP Connections with MultiConnect

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

Establishing Additional TCP Connections with MultiConnect

Overview: Accelerating requests and responses with MultiConnect

Most web browsers create a limited number of persistent TCP connections when requesting data, which restricts the amount of content a client can receive at one time. You can provide faster data downloads to your clients using the BIG-IP® device's MultiConnect feature.

The MultiConnect feature enables you to specify unique subdomains that prompt the browser to open more persistent TCP connections (up to five per HTTP subdomain and five per HTTPS subdomain generated by the BIG-IP device). The origin web servers never get a request from these additional subdomains; they are used exclusively on externally linked URLs or links that request images or scripts and are only for requests or responses between the client and the BIG-IP device. If the BIG-IP device needs to send a request to the origin server, it removes the subdomain prefixes before sending the request.

The BIG-IP device uses the MultiConnect feature only on the following types of links:

  • Image tags: <img src="...">
  • Script tags: <script src="...">
  • Forms whose input type is an image: <form><input type="image” src="..."></form>

Task summary for establishing additional TCP connections with MultiConnect

Perform these tasks to establish additional TCP connections with MultiConnect.

Task summary

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.

Configuring DNS subdomains for use with MultiConnect

Before you can configure DNS subdomains for use with MultiConnect, you must ensure that you have completed these tasks:
  • Configure DNS with entries for the additional subdomains.
  • Map the additional DNS entries to the same IP address as the base origin web server (for example, www.siterequest.com).
  • Assign specific prefixes to the additional subdomains. For example, if the requested host for the mapping is www.siterequest.com and you request additional subdomains for the HTTP protocol, you assign a subdomain prefix of wa.
The BIG-IP system changes the domain on qualifying embedded URLs and links so that they use the domains that you specify.
  1. On the Main tab, click Acceleration > Web Application > Applications .
    The Applications List screen opens.
  2. Click the name of an application.
  3. Click Options for a requested host.
  4. From the HTTP Subdomains list, select the number of HTTP subdomains that you want the BIG-IP system to generate for each protocol.
    The default is 0.
  5. From the HTTPS Subdomains list, select the number of HTTPS subdomains that you want the BIG-IP system to generate for each protocol.
    The default is 0.
    Important: Some client browsers close HTTPS connections to one domain before opening HTTPS connections to a new domain. This type of browser behavior can decrease the speed of access to applications for which the MultiConnect feature is enabled; therefore, do not enable the MultiConnect feature for HTTPS connections.
  6. In the Subdomain Prefix field, type a prefix.
    The default prefix is wa.
  7. Click Save.
The BIG-IP system now changes the domain on qualifying embedded URLs and links so that they use the domains you specified. For example:
  • wa1.www.siterequest.com
  • wa2.www.siterequest.com

Enabling MultiConnect for HTTP traffic

Before configuring MultiConnect settings, you must configure DNS subdomains for use with the MultiConnect feature.
The MultiConnect feature opens additional persistent TCP connections and is optimum for sites that have a high number of first-time visitors who are downloading a large number of images or scripts.
Note: Use the MultiConnect feature only if you have low-latency, high-bandwidth links, because the additional TCP connections also increase the amount of traffic to your site.
  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 options, as applicable.
    Option Description
    Enable MultiConnect To Modifies externally linked URLs to images or scripts that match a node with unique subdomains.
    Enable MultiConnect Within Modifies URLs to images or scripts within a CSS file that is linked or imported into an HTML document.
    Important: Setting any of the following Variation rule parameters to the Different Content option disables Intelligent Browser Referencing (IBR) and MultiConnect to the policy node. You must set these parameters to the Same Content option 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.
This applies the MultiConnect feature to the node, and modifies externally linked URLs with unique subdomains, prompting the browser to open more persistent TCP connections (up to five per subdomain generated by the BIG-IP device).

Enabling MultiConnect for HTTPS traffic

Before configuring MultiConnect settings, you must configure DNS subdomains for use with the MultiConnect feature.
The MultiConnect feature opens additional persistent TCP connections and is optimum for sites that have a high number of first-time visitors who are downloading a large number of images or scripts.
Note: Use the MultiConnect feature only if you have low-latency, high-bandwidth links, because the additional TCP connections also increase the amount of traffic to your site.
Important: F5 Networks® recommends that you do not enable the MultiConnect feature for HTTPS connections. Some client browsers close HTTPS connections to one domain before opening HTTPS connections to a new domain, which can decrease the speed of access to applications for which the MultiConnect feature is enabled.
  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 options, as applicable.
    Option Description
    Enable MultiConnect To Modifies externally linked URLs to images or scripts that match a node with unique subdomains.
    Enable MultiConnect Within Modifies URLs to images or scripts within a CSS file that is linked or imported into an HTML document.
    Important: Setting any of the following Variation rule parameters to the Different Content option disables Intelligent Browser Referencing (IBR) and MultiConnect to the policy node. You must set these parameters to the Same Content option 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.
This applies the MultiConnect feature to the node, and modifies externally linked URLs with unique subdomains, prompting the browser to open more persistent TCP connections (up to five per subdomain generated by the BIG-IP device).

Implementation result

This implementation configures BIG-IP® acceleration to modify externally linked URLs with unique subdomains, prompting the browser to open more persistent TCP connections.