Page 750 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

and use this map to determine the shortest path to the destination.

Common examples of distance vector routing protocols are
Routing Information Protocol (RIP) and Interior Gateway Routing
Protocol (IGRP), while common examples of link state routing
protocols are Open Shortest Path First (OSPF) and Interior
Gateway Routing Protocol (IGRP).

Transport Layer

The Transport layer (layer 4) is responsible for managing the
integrity of a connection and controlling the session. It accepts a PDU
(variably spelled out as Protocol Data Unit, Packet Data Unit, or
Payload Data Unit—i.e., a container of information or data passed

between network layers). A PDU coming from the Session layer is
converted into a segment. The Transport layer, which controls how
devices on the network are addressed or referenced, establishes
communication connections between nodes (also known as devices)
and defines the rules of a session. Session rules specify how much data
each segment can contain, how to verify the integrity of data
transmitted, and how to determine whether data has been lost.

Session rules are established through a handshaking process, so the
communicating devices are in agreement on the rules. (Please see the
section “Transport Layer Protocols” later in this chapter for the
discussion of the SYN/ACK three-way handshake of TCP.)

The Transport layer establishes a logical connection between two
devices and provides end-to-end transport services to ensure data
delivery. This layer includes mechanisms for segmentation,

sequencing, error checking, controlling the flow of data, error
correction, multiplexing, and network service optimization. The
following protocols operate within the Transport layer:

Transmission Control Protocol (TCP)

User Datagram Protocol (UDP)

Sequenced Packet Exchange (SPX)

Secure Sockets Layer (SSL)