Network Interface Layer; Internet Layer; Transport Layer; Application Layer - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - IP-IPV6-IGP CONFIGURATION GUIDE 2010-10-31 Configuration Manual

Platform Considerations

Copyright © 2010, Juniper Networks, Inc.

Figure 1: TCP/IP Conceptual Layers

Network Interface Layer

The network interface layer is the lowest level of the TCP/IP protocol stack. It is
responsible for transmitting datagrams over the physical medium to their final
destinations.

Internet Layer

The Internet layer is the second level of the TCP/IP protocol stack. It provides host-to-host
communication. In this layer, packets are encapsulated into datagrams, routing algorithms
are run, and the datagram is passed to the network interface layer for transmission on
the attached network.

Transport Layer

The transport layer is the third level of the TCP/IP protocol stack. It is responsible for
providing communication between applications residing in different hosts. By placing
identifying information in the datagram (such as socket information), the transport layer
enables process-to-process communication.
The transport layer provides either a reliable transport service (TCP) or an unreliable
service (User Data Protocol). In a reliable delivery service, the destination station
acknowledges the receipt of a datagram.

Application Layer

The application layer is the fourth and highest level of the TCP/IP protocol stack. Some
applications that run in this layer are:
Telnet
File Transfer Protocol (FTP)
Simple Mail Transfer Protocol (SMTP)
Simple Network Management Protocol (SNMP)
Domain Name System (DNS)
For information about modules that support IP on the ERX7xx models, ERX14xx models,
and the Juniper Networks ERX310 Broadband Services Router:
See ERX Module Guide, Table 1, Module Combinations for detailed module specifications.
See ERX Module Guide, Appendix A, Module Protocol Support for information about the
modules that support IP.
Chapter 1: Configuring IP
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