Virtual Consumer Nov-Dec 2013

Life begins at forty

Virtual Consumer column from Ethical Consumer magazine Nov-Dec 2013

Forty years ago on 10 September 1973, Vint Cerf presented a paper at Sussex University entitled “A Protocol for Packet Network Interconnection”. This was a crucial moment in the development of computer networking with profound consequences for the world today.

The ‘protocol’ that Vint described was ‘TCP/IP’: the standard that says how information travels across the Internet. It may seem a bit geeky, but the way TCP/IP works is important. It explains why the Internet has evolved into the world’s universal network and how it has had such an impact on business and governments. In order to understand why, it’s worth being familiar with two important characteristics of TCP/IP.

As Vint’s paper title suggested, TCP/IP is for packet networks. The ordinary telephone network uses ‘circuit switching’ - when you make a telephone call, a ‘circuit’ is made between your telephone and the person you are calling. There is a channel reserved for your call, and your call only, passing through the network between the two telephones. The Internet on the other hand uses ‘packet switching’. When two computers talk to each other there is no reserved channel, instead the computers send information in ‘packets’. Each packet has the destination ‘address’ marked on it: like a letter or parcel in the postal network, it can take a number of different routes between the sender and the receiver. The Internet is so big and complex there are actually thousands of different ways for packets to get from A to B. This is important because it makes it very difficult to stop a packet. That’s good for reliability and bad for governments. The Internet, as John Gilmore famously said, “interprets censorship as damage and routes around it.”

Secondly, Vint’s proposal was for network interconnection. Packet switching wasn’t new - there were many packet switching networks already. The new protocol offered a way to stick them together, to create a bigger network. Other packet switching networks were run by the big telephone operators. They could exchange traffic but they needed complex arrangements for charging each other. The TCP/IP protocol on the other hand simply assumed that participating networks would freely exchange packets. This has allowed thousands of independent networks to join together to form today’s Internet.

The simplicity of TCP/IP has helped ensure that the Internet has remained mostly free and open. This has its down sides - spam for example is widespread because packets are not charged. Early alternative networks like Minitel in France offered small information providers an easy way to charge for their information. On the Internet they must rely on advertising or complex ‘paywalls’, which favour bigger providers. Arguably however these down sides are a small price to pay for the transforming impact of the net. The next forty years could be even more exciting.