The OSI Model
Network (Protocols and Standards)
ARP, ICMP, IGMP, IP, IPSec, RARP
Presentation Layer (Duties)
Allows hosts and applications to use a common language; performs data formatting, encryption, and compression.
Layer 7
Application Layer #
Application (Protocols and Standards)
BOOTP, DHCP, DNS, FTP, HTTP, HTTPS, IMAP4,PING, POP3, NSLOOKUP, NTP, SFTP, SMTP, SNMP, Telnet, TFTP
Layer 2
Data Link Layer #
Transport Layer (Duties)
Ensures accurate delivery of data through flow control, segmentation and reassembly, error correction, and acknowledgement.
Network Layer (Duties)
Establishes network connections; translates network addresses into their physical counterparts and determines routing.
Session Layer (Duties)
Establishes, maintains, and terminates user connections.
Physical Link (Standards)
IEEE 802.3 (Ethernet), 802.5 (Token Ring), 802.11 (Wi-Fi)
Data Link (Protocols and Standards)
L2TP, PPP, PPTP, SLIP
Presentation (Protocols and Standards)
MIME, SSL, TLS
Physical Layer (Duties)
Manages signaling to and from physical network connections.
Layer 3
Network Layer #
Data Link Layer (Duties)
Packages data in frames appropriate to network transmission method.
Layer 1
Physical Layer #
Layer 6
Presentation Layer #
Application Layer (Duties)
Provides Interface between software applications and network for interpreting application requests and requirements. *Note: This layer is not the actual software application.
Session (Protocols and Standards)
RTP & SIP
Layer 5
Session Layer #
Transport (Protocols and Standards)
TCP & UDP
Layer 4
Transport Layer #