HTTP Flashcards
______ is the main application layer communication protocol of the world wide web
HTTP
A web page is made up of many objects including…
images, text, audio, video clips, animations, applets, and other components
An HTML file includes a _________ for each of the objects on the page
reference
What is an agent?
A browser
Agents use ______ to communicate across the internet
HTTP
To get the objects on an HTML page, the client must request the objects from the ______
servers
HTTP is used to send ______ from a browser to a web server
requests
What are the steps to access an object?
- Locate web server
- TCP connection is made
- Client sends a HTTP request for the object to the server (or a series of requests)
- Server processes request and sends a reply
- Client adds object to page and requests next object
In the original version of HTTP, a new ___ ________ would be made for every single object
TCP connection
Describe a non-persistent connection using SYN, ACK, and FINS
-A sends SYN (TCP req)
-B sends SYN ACK (Accept TCP)
- A sends ACK and HTTP GET
- B sends object
To close connection
- B sends FIN
- A sends SYN ACK
- B sends ACK
What is the round trip travel time?
The time it takes to propagate from A to B to A
Each non-persistent connection takes _ RTTT to make and break the connection
3
The default in HTTP1.1 is a ________ connections
persistent
Persistent connections close after a ________ time with no activity
reasonable
In a persistent connection, A must also send an ___ when it receives an object
ACK
What is pipelining?
Requesting an object as soon as the agent knows they are needed.
How does the server behave when there are pipelined requests?
The requests are queued and replied to sequentially
A GET request…
gets an object
A POST request…
sends user input information
A HEAD request…
is like a GET, but with no object in the response
What is the format of a request message?
- Request line
- Header section
- Blank line
- Entity Body
The request line indicates the…
method, URL, and HTTP version of the request
The _______ section includes details of the request such as field name and value of that field
header
The entity body contains the returned _____
object
GET requests have a blank ______ ____ because it does not return any object
entity body
The 200 status code signifies ___
OK
The ___ status code signifies Moved Permanently
301
The 400 status code signifies ___ _______
bad request
The ___ status code signifies Not Found
404
The 505 status code signifies …
HTTP version not supported
