HTTP 0.9 Protocol:
- Defined in 1991
- Latency is not at all a factor in HTTP 0.9
- In order to perform an http request client has to open a new TCP connection which is closed by server after responding to it.
- HTTP 0.9 User 3 way hand shake mechanism to establish a connection
- Its s simple text based protocol
- Only GET Method is allowed and Response Is HTML
- No Headers and Status Codes
- Invented by Tim Berners-lee at CERN
- Need a TCP connection for each Request
TCP 3 way Handshake:
HTTP 0.9 using telnet
HTTP 1.0 Protocol:
- Introduced in 1996
- HEAD and POST Methods were added
- Concept of header fields are introduced
- User-Agent introduced in Request (for debugging purpose)
- Content-Length introduced in Response (to identify the proper response)
- Caching , Authorization etc
- Still it Needs a TCP connection for each Request
- Status Codes are introduced
- Non-HTML can also be transmitted over this protocol
Telnet Using HTTP 1.0:
HTTP 1.1 Protocol:
- Published om 1997
- Persistent Connection Introduced
- The same connection can be used for consecutive request for single embedded documents like images etc.
- Chunked Responses were supported
- HOST header has been introduced. This allowed hosting different domains from same IP address
- Content Negotiation, encoding and type are introduced.
- GET, HEAD, POST, PUT, DELETE, TRACE, OPTIONS
Telnet Using HTTP 1.1
This header allowed the connection to be opened for some time
Telnet Using Keep Alive HTTP 1.1
- Started in 2015
- Http2 is a binary, multiplexed, network protocol
- Frames and streams are used to communicate using this protocol
- Frames are exchanged over TCP connection instead of text based messages. The following frame types are available.
- HEADERS, DATA,SETTINGS, or GOAWAY are different frame types.
There are two ways to use http2 protocol
- Using upgrade header
- Send an http connection with upgrade header
GET /index.html HTTP/1.1
Connection: Upgrade, HTTP2-Settings
HTTP2-Settings: <base64url encoding of HTTP/2 SETTINGS payload>
- Http 2 compatible server will accept the connection with switching protocols.
HTTP/1.1 101 Switching Protocols
[ HTTP/2 connection …
ALPN: Application level Protocol Negotiation:
ALPN allows a TLS connection to negotiate which application level will be running across it.
After establishing an HTTP/2 connection each endpoint has to send a connection preferences as a final confirmation and to establish the initial settings for http2 connection.
CURL Using HTTP 2.0
Here is the code rut a jetty server with http2 protocol