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Multi-layer Protocols Transcription

Welcome to our multi-layer protocols module. Most network protocols follow the OSI or the TCPIP models and operate at a single layer, but there are some exceptions. Asynchronous Transfer Mode or ATM is a protocol that operates at multiple layers. It is commonly used with sonic technology, and it is based on cell switching.

And it is a non IP protocol, commonly used to transfer voice, video, and data. There are three layers of the ATM protocol. The physical layer corresponds to the physical layer of the OSI model. And the ATM layer, and the ATM adaptation layer will roughly correspond to the data link layer of the OSI model.

A switched virtual circuit, or SVC, is created on demand, or a permanent virtual circuit, or PVC can be programmed in advance, and this can be thought of as a dedicated line for a specific customer. For the CISSP examination, you should remember that ATM is a multi-layer protocol. We also have devices that operate at multiple layers of the OSI model.

Proxy servers, for example, are advanced catching firewalls that perform many services such as network address translation as well as deep packet inspection of not only the header data but also the data contained within the packet. These devices operate at multiple layers of the OSI model. Gateways or media converters also operate at multiple layers.

While most switches are layer two devices, there are some switches that are layer three switches that can perform switch activities at layer two and router activities at layer three. This is commonly used for VLANs or virtual local area networks. Intrusion detection or intrusion prevention systems can also operate at multiple layers of the OSI model.

Also SCADA or ICS systems that allow you to monitor mechanical systems or provide site supervision in real time, operate at multiple layers of the OSI model. SCADA, or a supervisory control and data acquisition, operates at multiple layers of the OSI model. These are typically distributed systems, but are not generally cloud based, they are usually provided on site.

They're used to monitor and control manufacturing processes, industrial processes, and facilities using industrial control systems, or ICS. DNP3 is the primary protocol used for communication with these systems. And you should remember that for the CISSP examination. Due to security risks with these types of devices, computerized facilities are now a new target for attackers and hackers.

Cyber terrorists are a common threat today to all types of systems, but are particularly a threat to automated industrial control systems. Because a lot of these systems are not properly secured, so you may not need much resources in order to launch a cyber attack. Also these systems are used to control electrical systems, natural gas systems, water systems, and transportation systems.

So if an individual is able to take advantage of these systems they can cause a lot of damage in the physical world, not just in the online world. This concludes our multi-layer protocols module. Thank you for watching.