Karteikarten
HTTP, SMTP & MIME protocols
Karten in diesem Stapel (48)
- 1What is HTTP?A client/server application layer protocol that allows request and delivery of webpages
- 2What can webpages include 4 examples*HTML files
*Image files
*Audio files
*Java applet - 3What port does HTTP work on?TCP Port 80
- 4What does URI stand for and what is it?Universal Resource Identifier and it maps the resource on the web server
- 5What does URL stand for and what is it?Universal Resource Locator and it identifies and provides a way of locating and accessing a resource
- 6What does URN stand for and what is it?Universal Resource Name and its a globally unique name which exists even if the resources doesn't or isn't available
- 7What are URL's & URN'sA scheme
- 8What is this an example of http://www.uoslibrary.co.uk/books/Romeo&Juliet.pdfA URL
- 9What is this an example of? urn:isbn:0-486-27557-4A URN
- 10What are the 2 types of HTTP messages?*Response
*Request - 11What is a HTTP request message?An object is sent from the client to server
- 12What is a HTTP response message?An object is sent from the server to client
- 13Name 3 from the common methods for request and what they doGET - Retrieves data
POST - Create object, server controls URI
HEAD - Retrieves data only in response headers - 14What 2 states can methods be*Safe
*Idempotent - 15What is a safe method and examples?They only retrieves information examples are GET and HEAD
- 16What is a idempotent method and examples?Where the number of requests are the same examples are GET, HEAD & PUT
- 17What are the 2 HTTP connection types*Non-persistent
*Persistent - 18What type of connection is this and why?A non-persistent serial connection
- 19What type of connection is this and why?A non-peristent parallel connection
- 20What type of connection is this and why?A persistent connection, with pipelining and because its trying to download all the images at once
- 21What type of connection is this?A persistent connection, no pipelining
- 22What are the issues with using non-persistent connectionIt increases latency
- 23Why is persistent better than non-persistent and what is the technique calledIt's better because you don't have to keep re-establishing a connection everything is sent at once and this is called pipelining
- 24Are cookies stateless and what service do they provide state for?Yes they are they provide state for HTTP
- 25Why are cookies usedTo save information and preferences about users and use this to provide them with content matching their interests
- 26Explain what is happening in this example of creating a cookie
- 27What are web proxysThey're servers which are used to control passage within the internet
- 28How can web proxy be used 4 examples*Cache web pages
*Filter the requests which can be used
*Filter services users can use
*Filter time restrictions users can access the web on - 29POST is not an idempotent method. Why not?Because it doesn't send the same value when the request is made more than once i.e sends more than 2 objects if you change the fields on a form and submit it
- 30How do proxy servers work
- 31What is HTTP 2.0 and what does it focus on And What are the new features ?It's a newer version of HTTP 1.1 and it focuses more on efficiency
Features:
*Compressing the header field
*Enabling multiple concurrent message on the same connection (multiplexing)
*Enabling unsolicited (pre-emptive) ‘push’ from server to client. - 32What is HTTPSA securer version of HTTP which uses public, private keys and a symmetric key for secure communication
- 33How does HTTPS work
- 34Are there any issues with HTTPS?Yes if there is a proxy server involved it won't be able to decrypt the message
- 35What is SMTPIt's the main protocol for internet services
- 36How is HTTPS implemented and what layer does it use?It's implemented using SSL or TLS and using the transport layer
- 37What does SSL and TLS stand forSSL(Secure Sockets Layer)
TLS(Transport Layer Security) - 38How does SMTP work
- 39What are the 3 mail access protocols and their port numbers*IMAP - TCP 143
*POP3 - TCP 110
*HTTP - TCP 80 - 40What do the mail access protocols use to secure the communicationSSL/TLS
- 41What mail agents are used when sending an email* Mail User Agent (client mail application)
* Mail Service Agent (runs on the receiving server)
* Mail Transfer Agent (runs on mail servers to send mail to other mail servers)
* Mail Delivery Agent (runs on the destination mail server and delivers mail to the user’s mailbox) - 42What are the features of POP3*Simple mail access protocol
*Runs in download & delete (default) or download & keep mode
*Once downloaded, messages are only available locally
*State information not carried between sessions not secure - 43What are the feature of IMAP*Messages usually left on server until user deletes them
*Most email clients support IMAP
*Not all email services support IMAP
*State information maintained between sessions more secure than POP3 - 44Explain the labels for what the content looks like in an SMTP mail message
- 45What is the purpose of the ‘boundary’ definition in the email header?It defines the string that will be used indicate the boundary between body parts of a multi-part mail message.
- 46What does MIME stand for and what is itIt stands for Multipurpose Internet Mail Extensions and it allows you to send different types of data over the internet i.e images
- 47Name 2 types of MIME transfer encoding*quoted-printable
*base64 - 48—
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- Beschreibung
- System Admin Semester 2 Karteikarten am HTTP, SMTP & MIME protocols, erstellt von Tunds am 11/03/2015.
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- Tunds
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