Chapter 12 Load Balancing for FortiOS 5.0 : Configuring load balancing : HTTP and HTTPS load balancing, multiplexing, and persistence : HTTP and HTTPS multiplexing
  
HTTP and HTTPS multiplexing
For both HTTP and HTTPS load balancing you can multiplex HTTP requests and responses over a single TCP connection. HTTP multiplexing is a performance saving feature of HTTP/1.1 compliant web servers that provides the ability to pipeline many unrelated HTTP or HTTPS requests on the same connection. This allows a single HTTPD process on the server to interleave and serve multiple requests. The result is fewer idle sessions on the web server so server resources are used more efficiently. HTTP multiplexing can take multiple separate inbound sessions and multiplex them over the same internal session. This may reduce the load on the backend server and increase the overall performance.
HTTP multiplexing may improve performance in some cases. For example, if users web browsers are only compatible with HTTP 1.0. HTTP multiplexing can also improve performance between a web server and the FortiGate unit if the FortiGate unit is performing SSL acceleration. However, in most cases HTTP multiplexing should only be used if enabling it leads to a measurable improvement in performance.
To enable HTTP multiplexing from the web‑based manager, select multiplex HTTP requests/responses over a single TCP connection. To enable HTTP multiplexing from the CLI enable the http-multiplex option.