UK Universities form part of the global Internet via a connection to JANET, the UK academic and research network. On 1 August 1998, charging was introduced for each institution's use ofJANET transatlantic links. Currently, traffic from the US is charged at a rate of 2 pence/Mb during the hours 06:00 to 01:00 (though many universities will obtain subsidies from HEFCE or DENI).
By identifying domains within links to resources in a web site, it is possible to get a rough idea of the potential of the site to generate transatlantic bandwidth (although, of course, the situation is complicated by the use of caches, users entering URLs directly etc.). WebWatch therefore analysed academic library websites to explore this idea further.
Figure 1 shows the five most popular domains hyperlinked to from academic library web pages. Assuming that the UK domain implies that packets are not routed via the US, the chart shows that most links point to resources that will not directly consume transatlantic bandwidth. If the small number of other domains represent very popular resources, then there is still the potential to attract charging. In this case, such hyperlinks were found relatively deep within the web sites which may suggest that these will not be frequently selected.
Figure 1 - Top five hyperlinked domains