Module 15

What is the role of the application layer?

Provides the interface between applications and the underlying network

What is the role of the presentation layer?

Formatting, compressing, and encrypting data

What are some well known presentation layer data formats? (4)

PNG, MOV, GIF, JPG

What is the role of the session layer?

Initiates dialogs, keeps them active, and restarts disrupted/idle sessions

What are some popular application layer protocols?

DNS, DCHP, SMTp, POP3, IMAP, FTP, HTTPS

What is a P2P network?

Computers can share resources with each other

What are the 2 parts of a P2P network?

Network, applications

What do P2P applications allow a device to do?

Act as a client and a server

What are some common P2P applications?

BitTorrent, eDonkey, Freenet, Direct Connect

What request does a browser send to an HTTP server?

GET request

What file does a browser request from an HTTP server?

index.html

What are the 3 common HTTP message types?

GET, POST, PUT

What does HTTPS use to encrypt data?

SSL/TLS

What protocol is used to send mail?

SMTP

What protocol is used to retrieve email from an email server?

POP3 or IMAP

Where are SMTP messages stored when the destination server is unavailable?

A message spool

What is the difference between POP3 and IMAP?

POP3 sends emails to the client and deletes them while IMAP sends copies and keeps the original email stored

What format does DNS use for its messages?

Qiestion, Answer, authority, additional

What are the different DHCPv4 messages? (5)

DHCPDISCOVER, DHCPOFFER, DHCPREQUEST, DHCPACK, DHCPNAK

What are the DHCPv6 messages? (4)

SOLICIT, ADVERTISE, INFORMATION REQUEST, REPLY

What 2 connections does a host establish for FTP?

Control connection, Data connection