Lesson 4 - Session, Presentation and Application Layers Flashcards
Which Layer controls the communications from one endpoint to another.
Session layer
Name 3 Common Layer 5 modes of communicating
Full Duplex - Phone Communications
Half Duplex - two way radios
Simplex - Source can only send. Destination cannot respond
Name some common Layer 5 Protocols
H.2254
L2TP
NetBIOS
RPC
SMB
SOCKs
What main purpose of Presentation Layer (6)
Responsible for formatting and coding Application Layer data into a form that is acceptable for transmitting on the network
Which Layer would be responsible for formatting and encrypting of data
Presentation Layer
Name Some Common Protocols at the Presentation Layer
IMAP - Email
SSH - Secure Shell - cryptographic protocol
SSL - Secure Sockets Layer
TLS - successor to SSL - Transport Layer Security
Besides Encryption and Formatting what is another key function
Converting data into standard formats for application program use such as:
ASCII, ETCDIC, TIFF, JPEG, GIF, etc
Which layer only interacts directly with Human Beings
Layer 7 Application using User Interface
Name common Layer 7 Protocols
DHCP
FTP
HTTP
NFS
SMTP
SIP
SNMP
Telnet
True or False a Word Processor operates at Layer 7
False - that is not the type of application that this level is referring to
Which Port does HTTPS Use
443
Bonus - is aTCP Protocol
Which Port does FTP Use
20 and 21
Which Port does SMTP Use
25
Bonus - Is a UDP Protocol
Which Port Does Telnet Use
23
What Service does Port 80 Use
HTTP
Which Service does Port 53 Use
DNS
Which Services does Port 69 Use
Trivial File Transfer Protocol (TFTP)
Name the Most Common Application Architectures
Host-Based
Client-Based
Client/Server
Cloud Computing
Peer to Peer
What was the main pitfall for Client Based (Diskless) Applications
Saturation of network
What is the term for multiple appServers
N-tier
What is the rapidly emerging use case for untrusted P2P applications
Blockchain
What is an instance of a service listening for traffic on a specific port called
Socket
Where did what we call the Internet originate from
DOD used a network called ARPANET for research. Educational institutions and then Large Corp started using it.
In 1989 what English Computer Scientist proposed a novel way to connect resources across the Internt
Tim Berner-Lee created World Wide Web and created a new protocol called the Browser in 1991
What Technique does today’s mobile and distributed apps use
Representational State Transfer (REST)
What is the data at each of the layers of the OSI model called
Protocol Data Unit (PDU)
What are the PDU Data called at each of the layers
App/Pres/Session - Data
Transport - Segments
Network - Packets
Data Link - Frames
Physical - Bits 1’s and 0’s
Which ports are listening for DHCP
UDP 67 for Servers
UDP 68 for Workstations
Netbios, SOCKS, RPC, SMB are protocols at what layer
Session
Application environments that use remote procedure calls commonly operate using Layer 5
SNMP uses what ports to operate and what is the current version
Ports 161/162
SNMP version 3 which offers security such as authentication and encryption
Compare a Worm vs Virus
Worms are self replicating that insert copies of themselves into executable codes, programs or documents and replicate faster than viruses.
Which Service uses Port 179
BGP
Kerberos uses what Port
88
