Application 

The Application layer corresponds to the Session, Presentation, and Application layers of the OSI model.

Protocols associated with the Application layer include:
• FTP
• HTTP
• Telnet
• Simple Mail Transfer Protocol (SMTP)
• Domain Name System (DNS)
• SNMP
 

Transport

The Transport layer matches the Transport of the OSI model. This layer is responsible for:
• Error checking and reliable packet delivery.
• Breaking the data stream into segments.
• Assigning sequence numbers so the packets can be reassembled correctly on the remote side after transport.
Protocols associated with the Transport layer include:
• Transport Control Protocol (TCP)
• User Datagram Protocol (UDP)

 

Internetwork

The Inter-network layer is comparable to the Network layer of the OSI model. It moves packets through a network. This involves:
• Addressing hosts.
• Making routing decisions to identify how the packet traverses the network.

Protocols associated with the Internet-work layer include:
• Address Resolution Protocol (ARP)
• Internet Control Message Protocol (ICMP)
• Internet Group Management Protocol (IGMP)

Network

The Network layer (sometimes called the Link Layer) corresponds to the Physical and Data Link layers of the OSI model. It describes the physical layout of the network and formatting messages on the transmission medium.

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A comparison of the OSI Model and the TCP IP Model: Click here >> to learn about the OSI Model