In February, a new administration official stated that the smart grid requires "IP everywhere", stirring considerable concern among the dumbest (in terms of grid smarts) of the smart grid players. Earlier this month, as I wrote of in The Impulse to Run Around Naked, a maker of building systems asked why we don’t just build systems with their own native languages and their own "most optimal" media. The operators of the big distribution systems (SCADA) for electricity, water, sewage, and natural gas are all a-twitter over the proposed national cyber-security directorate. This agitation in those that manage the actions of the built world is based upon misunderstandings based upon poor definitions as much as anything else.
Access to each system should be IP-based, or have the characteristics of IP. (IP refers to the Internet Protocol, usually partnered in conversation with Transmission Control Protocol as TCP/IP.) These characteristics are what is important, any protocol that meets the same characteristics can be internetworked with IP. That internetworking is the only part that matters about "IP everywhere".
IP is first of all independent of underlying protocols. Fiber, cable, wireless, and phone lines all support IP. IP can adjust to the special requirements of underlying media, as it does for Zigbee (used in self assembling networks of low bandwidth digital radios), which is only similar to IP or in 6LoPAN (an explicit mapping of IP v6 to similar radios) as long as we define IP correctly. To me, as long as the access is open, I would count Zigbee and 6LoPAN as compatible with "IP everywhere".
IP is connectionless and unreliable–by design. Older networks used to rely on dedicated wires between points-I remember limited numbers of long distance lines all across the country. Connectionless protocols do not create a connection, even a virtual one, but send the data directly. IP makes no guarantees that a message will actually get there, or that a sequence of messages will get there in order. Properly designed IP applications embrace this design; properly designed IP applications will handle network degradation with only minimal loss of function. If we make something as big as the smart grid, we had better embrace this attitude.
IP is universally addressable. Despite firewalls, routers, NAT, and other security filters, under IP if you want to send a message to any device, and you have permission to send a message to any device, you can send a message to any device. Many of the worst security breaches have occurred when a system administrator did not bother with security because the network was unreachable. Unfortunately for them (queue Jurassic Park soundtrack) IP will find a way. What can be connected to the internet, will be connected to the internet. Critical systems should be managed as if connected to the internet; any security devices or isolation techniques are then only additional security measures.
IP is a protocol that is well understood, and that can be accessed by anyone. Any systems connected to the smart grid should be IP, or should be translatable to IP without loss. All interaction should be designed to accept new connections, and errors, because that’s how IP works. All systems should be designed as if anyone can connect at any time and to manage security and self integrity on that basis. All systems in buildings and on the smart grid must be designed this way if we are going to connect them all together.
In other words, we must build the smart grid as if IP is everywhere even if it isn’t literally everywhere.