The Four TCP/IP Layers

Begin Learning Cyber Security for FREE Now!

FREE REGISTRATION
Already a Member Login Here

The Four TCP/IP Layers:


The TCP/IP Application Layer: This pertains to communications services to applications and acts as a go-between for the network and the application. It also handles presentation and administering communication sessions. It encompasses the Application Layer, Presentation Layer and Session Layer of the OSI reference model. Examples: HTTP, POP3, and SNMP.

The TCP/IP Transport Layer: This layer addresses multiple functions, including selection of protocols, error recovery and flow control. This layer can also support retransmission, i.e., error recovery and may use flow control to curtail unneeded congestion by sending data at a rate the network can handle, or depending on the choice of protocols, it may bypass this function. Multiplexing of received data for various flows to applications on the same host is also preformed. Reordering of the incoming data stream when packets come in out of order is also handled. This is associated with the Transport Layer of the OSI reference model. Examples include: TCP and UPD, which are called Transport Layer, or Layer 4 protocols. TCP supports connection-oriented service while UDP offers connectionless support in the Transport Layer.

The TCP/IP Internetwork Layer: Also known as the Internet Layer, defines end-to-end delivery of packets and defines logical addressing to accomplish this. It also defines the process of routing and how routes are processed; and how to break down a packet into smaller packets to work with media with smaller maximum transmission unit sizes. It corresponds with the Network Layer of the OSI reference model. However, while the OSI network-layer protocols offer connection-based (Connection-Mode Network Service (CMNS), X.25) or Connectionless Network Service (CLNS), IP only provides connectionless network service. The routing protocols are network layer protocols assigned with an IP protocol number. Border Gateway Protocol (BGP) is different in that it uses a TCP port number; and Intermediate System-to-Intermediate System (IS-IS) resides over the data-link layer.

The TCP/IP Network Interface Layer:

View Topics

Our Revolution

We believe Cyber Security training should be free, for everyone, FOREVER. Everyone, everywhere, deserves the OPPORTUNITY to learn, begin and grow a career in this fascinating field. Therefore, Cybrary is a free community where people, companies and training come together to give everyone the ability to collaborate in an open source way that is revolutionizing the cyber security educational experience.

Support Cybrary

Donate Here to Get This Month's Donor Badge

 

We recommend always using caution when following any link

Are you sure you want to continue?

Continue
Cancel