HTTP Flashcards
(52 cards)
Network protocols are —- that define how entities in a network communicate with each other.
rules
Rules in network protocol covers?
- Identifying and establishing communication with other party
- Transmit and Receive data
- Message Formats
This is a network protocol that runs on top of TCP and IP. It governs communication over the web. It is used by the browsers, web server, and other entities on the web
HTTP
Who are the individuals behind the design of HTTP?
Tim Berners-Lee and Robert Cailliau
When was HTTP designed?
1990
There are request sent to a server either by (1)
- another server; or
- client programs called (2)?
Client Server (1)
User Agents (2)
This agents are programs that make HTTP request for human users
User-agents
What is the most common user-agent? But they can also be mobile apps, desktop apps, and machine automated user agents.
web browser
In here, HTTP communication is done through request and response messages
request-response
Where are request message sent, which handles it, then sends back a response?
web server
Is request-response an all time direct connection between user-agent and web server?
No, because sometime proxy exist in the middle.
In here, client and server are only aware of each other during the current request-response exchange.
Stateless
When client and server have multiple https transaction, are each request independent of that on the context of a previous request?
Yes
This transaction is the 1:1 exchange of request and response
HTTP transaction
What is the first step in a HTTP transaction?
- Browsers extracts server’s hostname
What is the second step in HTTP transaction?
- Browser resolves the IP address via Domain name Resolutiom
What is the third step in a HTTP transaction?
- Browser extracts the port from the URL
What is the fourth step in a http transaction?
- Browser establishes a TCP connection with the web server.
After a browser establishes a tcp connection with the web server what is next?
The browser send an HTTP request to the server
After sending a request to the server, what does the server do?
The browser receives a response from the server
After receiving a response, is TCP connection closed?
It depends on the http version
What does the browser do with the response from the server?
The browser parses the returned HTML doc, fetching additional resources as needed
These are web servers that act as intermediaries between client and server
Proxies
This type of proxy is used to pass messages from one part of the Internet to another. It is usually placed at the ‘edge’ of a local network to direct internal traffic to the public internet.
Forward Proxy