End-to-end versus end-to-end

If you’ve spent any amount of time reading about what the internet is, you will have heard it described as an end-to-end network.  End-to-end architecture is said to be a founding principle of the internet. It has often been invoked in discussions of net neutrality, or network management. It is typically understood to mean that the internet is decentralized: to the extent possible, control is best exercised by the computers at the ‘ends’ of the network, and everything in between (the internet ‘pipes’ and the networking hardware owned by the telecom companies) should be kept as simple (or ‘dumb’) as possible — limited to passing along data packets.

Now, it is possible to argue that the internet has never been decentralized. There are points of control in its architecture, through state institutions, and the ISPs that manage our experience of the internet. But this is only surprising if we lose sight of what the end-to-end argument was meant to be — not a statement of what the internet is, but what it ought to be.  This normative argument was premised on the notion of an authentic, original internet, but it was a fragile notion in danger of being lost, or intermediated out of existence. While the end-to-end principle was not intended as a description of reality, it did come to shape reality through its influence, as many people responsible for designing technologies, running networks, and governing connectivity took it seriously. However, countervailing pressures to move control from the edges to the center of the network will ensure that this will remain a constant point of tension.

The above is an argument largely based on Tarleton Gillespie’s article, Engineering a Principle: ‘End-to-End’ in the Design of the Internet. This article provides some STS-informed discourse analysis of the end-to-end principle, tracing where the term came from and how it has shifted over time. But there was another kind of end-to-end principle that preceded the internet as we know it today, and was became an obstacle to creative uses of telecom networks – a path that led us to the internet.

Gillespie doesn’t dive into this earlier notion of end-to-end, although he does reference some (Bell) sources from the early 1980s that use it to discuss virtual circuits and the need to provide end-to-end digital networking over an infrastructure composed of both analog and digital parts (or over the old telephone system). What is missing from the account is the history of the term before the 1980s, which is the background that these Bell authors have in mind when they discuss end-to-end. This alternate meaning of end-to-end persists today in numerous contexts, to denote roughly: ‘from one end to the other, and everything in between’. In the history of telecom, this meaning has been intimately tied to the notion of system integrity in the monopoly era.

The old end-to-end principle argued that the network operator must have full control of the network, from one end to the other, or that the carrier had end-to-end responsibility for communications. This meant control throughout the network, but also of the endpoints, so that only approved devices could be connected to it. The principle was also sometimes cited to prevent interconnection with other networks. In the US, regulations prohibiting “foreign” attachments to the telephone system were challenged by the 1968 Carterphone decision, but in Canada it took until later in the 1970s to displace the notion of end-to-end control and systemic integrity in telecom regulation.

It is interesting how the internet’s end-to-end principle is not just different from this earlier notion, but in many ways its mirror image. In the mid-20th century the telephone was seen as a “natural monopoly”, because it was best managed by a single provider with centralized, end-to-end control, protecting the system’s “integrity” from any unauthorized elements. The internet in contrast is cobbled together from various network and bits of hardware, its protocols allowing diverse autonomous systems to exchange traffic, and users can plug whatever devices they want into the endpoints.

What happened in between the fall of natural monopoly arguments, and the rise of the packet-switched commercial internet was the liberalization of telecom, effectively opening up the monopoly telcos to competition. The loss of end-to-end control made it possible for the internet to emerge. The old monopolies became incumbents, and had to give up some control over what happened over their wires.

In recent years, with a flatter internet, online intermediaries maintaining more control by deploying their own transport infrastructure, and “middleware” in the network making more decisions, the internet’s end-to-end principle is arguably under threat. But these concerns have been around for most of the history of the commercial internet. Fundamentally, these are issues about who and what exercises control over communication, rather than what the nature of our communication infrastructure dictates. Because of this, tensions about the relative power of the edges versus the middle will continue, but this also means that the history of these arguments continues to be relevant.

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