Network Layer Security

Modern computer networks today are characterized by

layered protocol architectures, allowing network designs

to accommodate unlimited applications and interconnec-

tion techniques. This layered approach allows protocols to

become modularized, that is, developed independently and

put together with other protocols in such a way as to create

one complete protocol. The recognized basis of protocol

layering is the Open Systems Interconnection (OSI) archi-

tecture. The OSI standards establish the architectural

model and define specific protocols to fit into this model,

which defines seven layers. Protocols from each of the

layers are grouped together into an OSI layer stack,

which is designed to fulfill the communications require-

ments of an application process.