HTTP communication usually takes place over TCP/IP connections. The

   default port is TCP  [], but other ports can be used. This does

   not preclude HTTP from being implemented on top of any other protocol

   on the Internet, or on other networks. HTTP only presumes a reliable

   transport; any protocol that provides such guarantees can be used;

   the mapping of the HTTP/1.1 request and response structures onto the

   transport data units of the protocol in question is outside the scope

   of this specification.