3.8 Configuring the HTTP/2 Protocol

Access Gateway supports the HTTP/2 protocol while interacting with the web browser. The HTTP/2 protocol helps to:

  • Reduce the latency by enabling full request and response multiplexing

  • Minimize protocol overhead using efficient compression of HTTP header fields

Access Manager provides the following advanced options to use this functionality:

  • Protocols h2:

    This option allows the browser to communicate with Access Gateway using the HTTP/2 protocol.

  • ProxyHTTP2 on:

    Access Gateway supports this option when communicating with the backend web server using HTTP/2 protocol. To disable the HTTP/2 protocol at the proxy level, add the pound(#) symbol before the ProxyHTTP2 option or remove it. This option can be applied at the proxy level. But note that only proxy level entry will take the precedence. If path based proxies are configured, then each path based child proxy would require this advance option to be applied, and applying it only at parent level will not apply to all the child path based proxies.

  • LogLevel proxy_http2:debug

    Set this option to get the HTTP/2 protocol debug logs for the communication between Access Gateway and the backend web server..

  • LogLevel http2:debug

    Set this option to get the HTTP/2 protocol debug logs for the communication between browser and Access Gateway.

NOTE:Access Manager does not support websocket communication while using the HTTP/2 protocol.

NOTE:Although, all the browsers send the HTTP/2 protocol by default, you can configure fall back protocols by adding h2 h2c HTTP/1.1 protocols in the same order. The most preferred protocol is HTTP/1 and it will always be selected unless a client only supports h2. Since we want to communicate using HTTP/2 to clients that support it, the order should be h2 h2c HTTP/1.1. Here, h2c implies that HTTP/2 protocol over clear text will be used. If the h2 and h2c protocols fail, the fall back protocol will be the HTTP/1.1. Following scenarios are some examples when you can configure the fall back protocols:

  • If specific browsers do not use this protocol by default.

  • If the users have not enabled this protocol.

For more information about the advanced options, see Section 3.6, Access Gateway Advanced Options.