Topic #10: Application Layer Services and Examples Flashcards
These identify applications and application layer services that are the source and destination of data
Port Numbers
What addressing scheme does the transport layer use?
Port Numbers
Port Number for the Domain Name System
TCP/UDP port 53
Port Number for HTTP
TCP port 80
Port number for SMTP
TCP port 25
Port number for POP
UDP port 110
Port number for Telnet
TCP port 23
Port number for DHCP
UDP port 67
Port for FTP
TCP Ports 20 and 21
Two things that make DNS Work
DNS Protocol and DNS Resolver
This defines the automated service that matches the resource names with the required numeric network address
DNS protocol
This supports the name resolution for the other network applications and other services that need it
DNS resolver
Record type that means an end device
A
Record type which means an authoritative name server
NS
Record type that is a canonical name for an alias
CNAME
Record type that means Mail Exchange Record
MX
Steps in using WWW Service and HTTP
- URL is typed in the address bar
- browser checks with the DNS server and converts it to an IP address
- Connects to the server requested
- Using HTTP the browser sends a GET request for the desired HTML document
- the server sends the HTML for the webpage
- browser interprets the HTML code and formats the page
The email client when people compose e-mails.
Mail User Agent
Applications and services for MUA to use
POP or POP3
SMTP
What protocol to use when Sending email?
SMTP Protocol