The reason it makes sense NOT to jump into deep packet inspection (or, as you ask, starting at L1), is that starting at an app layer you have a holistic view of *every* possible link in the chain. If ...

Layers 7 through 4 are geared more to the application than the lower layers, which are designed to move packets from one place to another no matter what they contain. This top layer defines the ...

According to the OSI Model, the session layer is where connections are established, managed, and torn down. For connection-oriented network protocols, understanding how the session layer works, and ...

For many in the communication industry, the open system interconnect (OSI) network model is a simply a stack. But, designers shouldn't be so quick to diminish the value that the OSI model provides to ...

I like to think of the transport layer as the layer of the OSI Model that enables more interesting traffic. While we network engineers may love a lot of the simpler uses of the IP protocol and ...

Technology people are generally familiar with the Open SystemsInterconnection model for computer networks and protocols, oftenreferred to as the OSIReference Model (ISO 7498)[1].The Basic Reference ...

The line between middleware and application software is blurred, which is why this chapter introduces both together. Middleware is software that has been abstracted out of the application layer for a ...

Getting started on designing a network is a task of formidable proportions, but all the more so if you are looking to build a secure IT network. Often, IT system administrators are not fully familiar ...

For many years, security monitoring relied on gathering data from layer 4 of the OSI model through such data types as NetFlow. Because layer 4 data dealt with the transport layer, it isn't the most ...