Internet Addressing

The continuous increase of substation protection, automation and control systems based on a local area network, and especially the success of IEC 61850 has resulted in a huge number of devices with Ethernet interfaces to be used in such applications. This is makes many protection specialists set the IP address of the relays to allow each device to talk to its peers over the substation LAN. Probably many people don't know that an IP address (32 bits or 4 bytes, for example 192.168.1.25), is actually an IPv4 address. And that there is a problem because we are running out of them.

Since IP v4 was first standardized in 1981, at the time no one could predict the explosion of devices with networking capabilities - just look at all the mobile phones around. Because of that, experts in the communications industry estimate that some time in 2010 we are going to run out of IPv4 addresses available from IANA (Internet Assigned Numbers Authority). They are locally registered by RIRs (Regional Internet Registers). Different solutions to this problem have been discussed for years, but there is a lot more work to be done. More than 10 years ago IETF (Internet Engineering Task Force) decided to replace the IPv4 addressing scheme with a 128-bit addressing scheme in IPv6. Other benefits that IPv6 provides include built-in security with IPsec and autoconfiguration of devices. Until recently there has not been any significant increase in the use of this new addressing scheme, but this is to change soon. A memorandum for the Chief Information Officers of all US government agencies issued about three years ago, set June 2008 as the deadline for transition from IPv4 to IPv6.

The time has come for the PAC industry to start not only discussions, but taking measures for the transition to the IPv6 in order to ensure that all new exciting applications based on IEC 61850 and other communication protocols can keep working in the future.


Relion advanced protection & control.
BeijingSifang June 2016