Chapter 2 Flashcards
User vs network oriented application layer protocols:
User = interact with end user
network = manage network
Why was LDAP implemented
Lightweight Directory Access Protocol:
Simplify access control to various applications being used on a network
3 Different types of network architecture:
1) Client-server
2) Peer-to-Peer
3) N-tier
What is a daemon?
Server software that starts when computer is started until shut down
What is the drawback of the Client-server network architecture?
Client always initiates communication
Fix: Peer-to-peer architecture
What is good about P2P ( Peer-to-peer ) networks?
No central server
Workloads shared among all nodes
Challenges of a P2P network?
Security + management
What is the 4 email protocols:
X.400
SMTP
POP3
IMAP4
What standard does the x.400 refer to?
ITU-T standards
What are the different elements that could be in a X.400 header?
C = country
A = admin management domain
P = private management domain
O = organization name
OU = organization unit
G = Given name
I = Initials
S = surname
How does x.400 notation look like
“I=J;S=Doe;O=acme;OU=sales;A=sapo;C=za”
Who will this x.400 email be sent to?
“I=J;S=Doe;O=acme;OU=sales;A=sapo;C=za”
J Doe who works at Acme in sales in south africa. sapo = south african post office
What does smtp stand for?
Simple mail transfer protocol
What rfc is SMTP defined by?
5321
What does smtp use to handle messages?
“agents”
What are the 2 agents in smtp?
MUA (mail user agent) MTA (mail transfer agent)
What is used to transfer an email for one UA to another UA?
1+ mta’s ( since the email needs to be transferred from one user to another )
What is the task of the MUA in SMTP?
Simply a piece of code that accepts a message and forwards it to a MTA ( sender )
Accept incoming mail and store in directory (receiver )
What is the task of the MTA in SMTP?
Find a route from sender to receiver and forward email along that route.
How do you indicate which MTA you would prefer to use?
Using the “preference”
What do MTA’s add to emails they process?
A header line “Received: “
What is the first thing you send to the SMTP server once you have connected to it?
HELO or EHLO ( extended hello )
How do you indicate who the email is from in SMTP?
MAIL FROM:
How do you indicate who the recipient of an email is with SMTP
RCPT TO: