ISPs using BT’s broadband network including Plusnet suffered a major broadband outage affecting large numbers of users in northern England, Scotland and Northern Ireland, it has been reported.

During the morning, complaints about Plusnet started appearing on Twitter, the barometer of modern service problems for almost any company these days.

“No Internet connection for at least 6 hours isn't helpful when you run small home business Scotland & Northern Ireland affected!,” was typical of the comments.

Customer service seemed poorly informed about the problem, with one engineer denying knowledge of any problems despite the automated service message mentioning the issue.

“We've been made aware that a number of lines in the North of England and Scotland have been disconnected from the Internet this morning,” read a service message on Plusnet’s website.

“This is due to an issue which is currently being investigated by our suppliers and we hope to provide further updates as soon as possible.”

Service resumed after 11am and is believed to have been caused, no surprise, by BT’s 20CN and 21CN system.

Disruptions to fixed broadband connections affect all networks from time to time, including Plusnet, a BT subsidiary that uses the telecom giant’s infrastructure.

Earlier this year, Plusnet customers suffered significant problems after a maintenance upgrade went awry, and there have been intermittent problems on a smaller scale in Scotland in recent weeks.

Miffed customers could always move to a company famed for its excellent service, retailer John Lewis but then again the underlying infrastructure for this is also provided by Plusnet.

An interesting issue is why fixed broadband problems often get less attention than similar issues on mobile networks.

O2 suffered a major problem in July 2012, which received widespread and embarrassing attention, followed by a smaller issue in October.