Iran has reportedly renewed plans to set up a national intranet by August to control what the country's millions of internet users can see on the web.
The International Business Times, citing a statement from the country's ICT minister, reported that internet users would be assigned an Iran Mail ID for authentication purposes, and that all ISPs would have to present the intranet to users in four months.
Services from the likes of Google, Yahoo! and Hotmail would be blocked, as would proxies that potentially allowed users to skirt bans, according to the report.
Internet access issues have plagued Iran "since opposition supporters used social networking sites to organise widespread protests after the disputed 2009 re-election of President Mahmoud Ahmadinejad", Reuters reported.
Iran raised the prospect of a national email system in February 2010, when it blocked citizen access to Gmail.
The move to a wider 'National Internet' was flagged in January of this year by Iran's information minister in comments to the Islamic Republic News Agency.
The National Internet was expected to limit internet options for ordinary Iranians, while affording greater access privileges to government institutions and large firms, the Washington Post reported at the time.
The launch of the National Internet comes after an increase in service blockages in recent months.
In February, the Washington Post noted that software that previously allowed Iranians to bypass the state-run firewall had been hobbled.
A month later, Ars Technica reported the Iranian Government was blocking access to sites that used the HTTPS security protocol.
Shutting down the internet could have unintended consequences.
Australian National University professor Lawrence J. Saha noted last year that in the case of Egypt - where the internet was shut down during the overthrow of the Mubarak regime - internet closures "made revolution more diffuse and more difficult for the authorities to contain."
Spiegel Online also noted that, in the case of Egypt, internet closures on a large scale caused major negative economic impacts in the country.