Buildings IoT

On the Buildings IoT “One Network” Debate and What’s Been Missing from the Conversation

By Brian Turner | September 14, 2017

Buildings IoT and its broad counterpart the Internet of Things is sparking debate around physical building networks and where best to implement enterprise solutions that touch both IT and OT. At OTI, we have:

The Right Questions

The real debate is not around proving there is one right way to implement an IoT strategy for any one network – there are use cases where it’s clear which one of the three options is best. And just because one network architecture works in one implementation doesn’t mean it will make sense for the next one.

The question to be answered when considering where IoT solutions should plug into a network is how will the human interaction be impacted when building devices communicate over IP networks rather than RS-485 networks? Once we understand the human side of the equation, we can more accurately define how the network should be architected and how IT and Facilities (also known as operational technology, or OT) should engage with the project.

Programmer holding laptop and checking machine

The ground floor – technicians and controllers.

Technicians need continual access building devices in a convenient, efficient way. When controllers are on an RS-485 network like BACnet MSTP, technicians have unencumbered access for programming, data sharing, and commissioning. When these devices include IP connections, they need an IT network.

In most cases, when a technician today needs to create a network for an IP-connected building device, they bypass IT and install CAT5 or CAT6 cables and cheap, unmanaged switches to go back and forth between controllers. They do this because ease of connectivity is integral to their jobs. They need to do continuous programming and commissioning on building devices and bothering IT to open a port every few days is untenable for both parties.

While the CAT5 workaround provides the technician the access they need, it can open up the corporate IT network to unwanted and unnecessary security risks.

The network layer – new solutions, new problems.

Many enterprise organizations around the world are working to solve the secure OT network problem, and several already have workable solutions available on the market. In all honesty though, the most effective solutions have mostly moved the burden to IT. This does solve the connectivity and security problems, but it adds a whole host of issues for both teams.

In an existing operation, it is straight forward to get new switches and ports assigned from IT for OT systems. The problem is not in the complexity but in the delivery. In my experience, there are often significant delays to integration projects because of IT-related hold-ups. This is mostly due to lack of experience with and knowledge of the OT devices, operating systems, personnel and services required to integrate building systems.

The problem is exacerbated in new constructions because IT isn’t there until the building is occupied. This can be weeks or months after the building systems need to be online. OTI has been involved in several projects where 80-90% of the devices are connected via IP and need to be online well before the IT staff is ready for them.

We have managed through the project implementations and have worked with IT groups to make sure we are installing products and cabling they will be prepared to support once they are on site, but this is far from a perfect process so far.

Maintenance Difficulties

  1. How will IT and Facilities work together to maintain these networks?
  2. How will IT respond to the service needs of OT?
  3. Will OT control their own destiny or will they be tied to IT for all support and troubleshooting?

I was moderating a session at IBCon in San Diego earlier this year where the “One Building One Network” question was a leading topic. I said something to the effect that OT needs to the own their network and control their destiny. This was taken out of context by some so I will take this opportunity to explain the nuance.

Two problems must be addressed as we consider the proper technical backbone for both IT and OT networks:

  1. Technicians and operators maintaining building systems have been handling operations for years without additional resources. They have become accustomed to diagnosing problems with RS-485 and Lon networks. They’ve accumulated a lot of expertise in troubleshooting these systems.
  2. The IT requirement of one port per connected device. This will need to change in order to cost effectively implement large scale deployments of OT devices.

There is no doubt it makes sense to manage one network infrastructure for all things connected to the IT network. It also makes sense that the IT professionals should manage the network, at all levels. The part where I deviate from the “One Network” pack is applications on the network.

I believe OT staff needs to be in control of network related to devices and systems defined as Operational Technology. These systems are HVAC controls, lighting – anything considered part of the operation of a building or campus.

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This means IT must provide tools and access to OT staff. It can be very complex to grant access to certain management tools without creating security risks on the IT network.

The new future – why “us against them” is the wrong way to go.

This is where new innovations are hard at work to eliminate these problems. The product we use is Optigo Connect by Optigo Networks, which employs passive optical networking (PON) to allow the OT segments of the IT backbone to be installed in a much more cost-effective way than traditional fiber infrastructure.

The user experience is also fairly intuitive. It allows the OT group to manage ports, port VLan assignments, and PoE. They can monitor the bandwidth and connection status to make sure devices are behaving properly and sharing data across the network.

The IT group still manages access, routing, security, firewall rules, and other traditional IT responsibilities. But the OT staff is empowered to “own” and operate the building systems.

It/OT Backbone part 2

The second part of this IT/OT backbone conversation is about ideology more than technical ability. To explain, let’s get technical for a minute with an example. Consider a floor with 30 VAV controllers serving conditioned air to offices and open areas on a typical floor. Manufacturers like Distech Controls and KMC have created VAV controllers that connect using IP cables.

When used in combination with the Optigo Connect, the ethernet switch supports the Rapid Spanning Tree Protocol (RSTP) as well as a ring monitoring function to automatically switch off redundant paths, and a broadcast storm protection function. This creates some redundancy if a connection is broken in the middle of the floor.

New vs. Traditional

If we were to use the traditional IT paradigm for this scenario, we would install 30 CAT5 cables that terminate in a single port on a network switch. This adds a lot of cost to the overall implementation and is not likely to perform at scale.

In the new paradigm, CAT5 cables are installed in a daisy chain requiring only 2 cables that terminate into 2 network switches. The only cost impact is the two ports and the material. The labor is identical. The advantages for network performance, data access, and stability are tremendous.

This is just one example. To evolve with the IoT presents daily challenges for IT, OT and the points at which they overlap. Rather than thinking of it as one network against the other, the IoT requires new thinking on the parts of both teams. The ability to find solutions that help everyone meet in the middle.

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