A Practical Guide to Using the Industrial Internet Connectivity Framework
than the overlapping one
Misconception figure (Figure 1).
in
the
different challenges than enterprise
networks do. Most importantly, industrial
systems combine complex, intimately
interconnected software modules and
devices. Interoperability between the
various components is the most demanding
requirement on the architecture. With crisp
definitions of interoperability, the other
requirements can be much better
understood. The IIoT Connectivity stack
shares layers 1-3 with the OSI model and
defines levels 4 through 6 in terms of the
interoperability provided.
This may sound distressing, but in reality, the
lack of overlap in the IIoT space actually
makes an architect’s task much simpler. The
real problem is not choosing between similar
options; it is understanding the different
options and overcoming biases.
The Industrial Connectivity Stack
The Internet has well-developed layered
stack models, most notably the OSI “7-layer”
model and the Internet “4-layer” model.
However, the IIC experts found that these
models did not adequately capture the
requirements of industrial networks. Thus,
the IICF defines a new model, called the IIoT
Connectivity Stack Model (See Figure 3).
The layers focus on what is exchanged. At
the network layer, participants exchange
bounded-length packets of information. This
is usually implemented by the familiar
Internet Protocol (IP).
Figure 3: IIoT Connectivity Stack. Below layer 3 “Networking”, the IIoT stack duplicates traditional Internet
stacks. Above, it focuses on clarifying the interoperability that industrial IoT systems need.
Above it, the transport layer exchanges
variable-length messages. Participants share
opaque sequences of bytes. Participants using
Both the Enterprise Internet and the
Industrial Internet function by sharing data.
However, industrial systems present
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