Vendors in Rangoon have reportedly been told to block sales of unregistered SIM cards as the continued slowdown of Burma’s internet compounds communication problems.

The order was given on 2 November, a vendor on the Mahabandoola Road in central Rangoon told DVB, and targets those who have not registered their mobile phones with authorities.

A permanent SIM card costs around $US1000, while pre-paid cards normally retail for $US20. A few vendors who retained cards are selling them clandestinely for $US30.

The ban follows a major cyber attack against the country’s main internet server, controlled by the state-owned Ministry of Post and Telecommunications (PTT). Some analysts believe it was orchestrated by the ruling junta in an effort to block journalists sending information about tomorrow’s elections to overseas media outlets. State media has said however that it was an attempt by exiles to thwart the elections.

According to techeye.com, the DDoS (distributed denial-of-service) attack was between 10 and 15 Gbps (gigabits per second), which can easily overwhelm the country’s 45Mbps T3 terrestrial and satellite links.

Although it peaked on 2 November and has now weakened, connection to the internet remains patchy and slow: loading a YouTube clip, for example, takes hours. Access to free email accounts such as Gmail and Hotmail is also highly sporadic.

The DDoS method was used in September to paralyse three websites belonging to exiled media groups, including DVB. Because of the use of so-called ‘botnets’ around the world – computers that have been infected with a virus that activates a flood of traffic to a server – finding the source of a DDoS attack is difficult.

Suspicions however rest on the junta, and a possible dry run before the controversial Sunday vote. Foreign journalists and observers are banned from entering the country and domestic reporters prohibited from going within 50 metres of polling stations.