The UK's research network could be dismantled if higher charges prompt institutions to turn to commercial internet providers instead, university IT directors have warned.
Funding for JANET, which provides internet access and other services to universities, colleges and schools, could increasingly come from direct subscriptions from universities rather than funding and research councils.
But a report by the Universities and Colleges Information Systems Association (UCISA), Future Funding of JANET Services, warns that almost all the IT directors surveyed would try to find better deals if the direct costs of JANET rose.
Peter Tinson, UCISA executive secretary, said that in some areas, commercial alternatives were cheap enough for a "tipping point" to be reached if the cost of subscribing to JANET rose substantially.
"In certain areas of the country, particularly metropolitan areas, the cost of commercial providers and the availability of commercial infrastructure means that, if the cost of JANET rises significantly, IT directors have said they will look at commercial alternatives," he said.
If city universities abandoned JANET, rural institutions in the network could end up "paying significantly more than their urban counterparts," Mr Tinson added.
In February, a report by Sir Alan Wilson recommended that Jisc, the UK's higher education IT consortium that funds JANET, should be paid for by a "combination of grants and subscriptions/user charges" instead of relying on the UK funding and research councils.
The report cited the "era of financial constraint" as one reason why the Jisc funding model should change. Capital funding for the body fell from £37.5 million in 2007-08 to £.6 million in 2010-11.
Mr Tinson said that JANET offered more than internet access to universities, including a computer security team dedicated to the network, domain name registration and a videoconferencing service.
Commercial network providers "wouldn't really be monitoring the higher education sector" and so might offer a poorer security service.
He also claimed that it would become harder to create a national cloud computing network without the JANET service.
"If you haven't got that central focus, a coordinating point, then things are less likely to happen. You are not going to get the same economies of scale."
Seb Schmoller, chief executive of the Association for Learning Technology, agreed, saying that "network infrastructure is a bit like the postal service - if everyone uses it on a shared basis, then it can be provided cost-effectively to a very high standard at a flat rate".
"It may be that some institutions in metropolitan areas could get what they need more cheaply from commercial suppliers. But that would put up the costs for everyone else. In particular, institutions in remoter areas and those with a lower density of infrastructure-using businesses would be put at a big disadvantage," he said.
Malcolm Read, Jisc executive secretary, said that JANET was "an essential national asset".