There are several universal laws in the networking world that we must all abide by. Understanding these laws gives us deeper insight into the connected world we live in. Like civil law, in some cases these laws are not necessarily meant to be broken. Other laws just beg to be broken in an attempt to innovate network technologies. Here are the laws of the physical networking universe that is continually expanding.
Metcalfe's Law
Bob Metcalf's insight into networking is legendary. His law states that "the value of a network is proportional to the square of the number of connected users." For example, when a network is just a point-to-point link between two users the network has a value of 4 (2^2). However, when the network allows full-mesh connectivity between 100 users then the value is 10,000 (100^2). Now the Internet has about 2.7 billion users so its value is approximately 7X10^18.
Beckstrom's Law
Some may be aware of Rod Beckstrom's law as a revision of Metcalfe's law. Beckstrom's Law states "The value of a network equals the net value added to each user's transactions conducted through that network, summed over all users." This law is applicable to social networks and other connected populations. If only one person was logged into a social media site then no one would care and the value is nil. However, when all your friends and their friends are connected, you are unable to avoid getting sucked into the vortex. Networks can be like big friendship pyramid schemes.
Reed's Law
David Reed created a law that also tries to describe the value of a network. Reed's Law states that the "utility" of large networks can scale exponentially with the size of the network. This is similar to Metcalfe's law but does not state that the value is square of the number of connected nodes. It also is calculated based on the number of people connected like in a social network. Reed determined that the number of sub-groups in a social network is (2^N - N - 1) where N is the number of users of the network.
Sarnoff's Law
David Sarnoff created a law that states that "the value of a broadcast network is directly proportional to the number of viewers". This law has more to do with television viewership, but is equally applicable in the digital age of online videos. An example of this is that a channel with 10,000 viewers is 100 times more valuable than a network with 100 viewers. The same could be said for the number of receivers on a multicast channel. Think of that the next time you watch the Gangnam Style video with it many millions of viewers.
Postel's Law
Everyone owes a debt of gratitude to the Internet pioneer Jonathan Bruce Postel (Jon Postel). His sage advice helped guide the way that the Internet Protocol has been standardized. His law states that protocol developers to "be conservative in what you do; be liberal in what you accept from others". This "Robustness Principle" allows for interoperability between Internet systems and has been used when designing many communications protocols. Without this concept, hardly anything in networking would work right. Thanks Jon!
Snyder's Razor
Joel Snyder, Senior Partner at Opus One and frequent Network World writer says "All other things being equal, choose the more secure option." This is a security twist on Occam's Razor which says "All things being equal, chose the simplest solution". This is similar to the R. Buckminster Fuller quote "When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong." A good example of this would be the choice to use weaker or stronger IPsec algorithms and key lengths. If it doesn't cost any more or take any more time to configure the stronger options, then you should go with the stronger security configuration. These concepts of simple-design should instantly pop into your head when someone suggests using Policy-Based Routing.
Murphy's Law
Everyone is familiar with the saying "Anything that can go wrong, will go wrong" as Murphy's Law. When this is applied to computer networks the law reads something like "the more nodes in a network, increases the system's complexity, thus, the more likely a failure will occur." In other words, the MTBF may be smaller than you previously thought. Murphy can also take the form of a human attacker and in that case the law changes to something like this. The insecurity of the network increases exponentially with the number of nodes on the network.
Godwin's Law
Mike Godwin first wrote an Internet adage or meme in 1990 regarding the culture of chat groups. His law states that "As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one." Variants on this law are Earle's Law which states "As any discussion of online/virtual game economies progresses, the likelihood of EVE Online being mentioned approaches 100%." Yet another variation says that "The more times Deus Ex is mentioned in a discussion, the probability of at least one person (re-)installing it approaches 100%."
There are many great networking laws that we should live by and help explain the networked world we live in. Other laws that form the foundation of networking include Nyquist-Shannon Theorem, Ohm's Law, Barlow's Law, and countless others. In networking, each layer of abstraction relies on the foundation created by the previous layers. We all owe these visionaries a debt of gratitude for today we stand on the shoulders of giants.
Scott