Session Protocol

Traffic Server supports some session level protocols in place of or on top of HTTP. These can be provided by a plugin (see New Protocol Plugins) or be one that is supported directly by Traffic Server. Note that the SPDY protocol is deprecated as of v6.2.0, and will be removed in v7.0.0.

Session protocols are specified by explicit names:

  • http/0.9
  • http/1.0
  • http/1.1
  • http/2
  • spdy/1
  • spdy/2
  • spdy/3
  • spdy/3.1

The session protocols supported on a proxy port are a subset of these values. For convenience some pseudo-values are defined in terms of these fundamental protocols:

  • http means http/0.9, http/1.0, and http/1.1
  • spdy means spdy/3 and spdy/3.1.
  • http2 means http/2

Each proxy port can be configured in :ts:cv:`proxy.config.http.server_ports` to support a subset of these session protocols. For TLS enabled connections this configuration controls which protocols are offered by NPN. Protocol sniffing is use for non-TLS proxy ports to determine which protocol is being used by the client. If the detected protocol is not supported for that proxy port the connection is dropped.