The Supply Chain Explained

GÉANT is a pan-European backbone network. It provides connections between the networks of its European NREN partners. Although it is ultimately provided for the benefit of Europe's researchers and academics, GÉANT does not actually connect individual researchers directly - rather, it does so indirectly through a sometimes quite complex "network of networks". This is known in the research networking business as the Supply Chain, and an attempt is made here to explain how it works.

The end-to-end research network supply chain – in other words, the link from one individual researcher to another - can sometimes involve many different networks. For example, if a researcher is working at a university campus, he or she is probably connected to the campus network, or LAN. The LAN would probably connect to the university's network, which in turn may be connected to a metropolitan or regional network. This may then connect to the national network (NREN) of the country in which the researcher is located.

Data sent by this researcher to a colleague or computer facility in another European country would typically be sent across all of these networks before it reached GÉANT, which would provide the internatinal connection between the researcher's country and that of his or her colleague, or the destination computer. But this, of course, is only (just over) half the story: to reach its destination, the data has to exit GÉANT and flow across another series of networks, in the reverse order to that described above.

As a result of this hierarchical organisation of research networks in Europe, there can sometimes be as many as 13 different networks involved in providing end-to-end connectivity between two points. The ability for data to pass smoothly across all these different networks is vital to the data's efficient and rapid transmission;  incompatibilities between different networks' services or equipment configuration can easily cause delays and loss of quality. The efficient end to end working of the supply chain is one of the most significant challenges faced by the research networking community today.