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 #