KARACHI, July 27: The Pakistan Telecommunication Company has started to block those proxy servers which were increasingly being employed by Internet users to access proscribed websites.

This was stated by well-placed sources in the telephone utility on Sunday.

Internet users in the country turn to proxy servers, thousands of which are available on the worldwide web, to access websites which have been banned and blocked by the government.

Internet access to proscribed websites are blocked by the Pakistan Internet Exchange (PIE). In October last year, the PIE placed a ban on Internet telephony or voice chat websites. PIE, which is a PTCL subsidiary, has been blocking sites offering pornographic and other objectionable content since Jan 2003.

The sources said that in technical parlance proxy servers employed a technique in which one host, usually a router, answered address resolution protocol requests intended for another machine. “By faking its identity, the router accepts responsibility for routing packets to the real destination. The Proxy ARP allows a site to use a single IP address with two physical networks,” they said.

They explained that a proxy server was a server that would act as a “middle-man” between a user and whatever else the user connected to. “It is most commonly used as a ‘safety net’ for your connection. Using a proxy usually hides the true identity of the person using it,” they said.

The secretary of the Internet Service Providers Association of Pakistan, V.A. Abidi, told Dawn that the blocking of websites by the PTCL had significantly slowed down the Internet speed in the country. He said: “The addresses of those websites which have been banned have to be listed on the PTCL router. Whenever a user makes a request, the system looks up the list to determine whether it contains the request or not. This tedious process naturally takes a lot of time.”

Analysts say that using a proxy server is a simple process. “All a user needs to do is to find a list of free proxy servers by using an Internet search engine, such as google. Free proxy servers allow users to access all sorts of websites, even those which have been banned by the government in Pakistan.”

They recall that some time back India had blocked Dawn’s website. “Hundreds of thousands of Internet users in India had employed proxy servers to access Dawn’s website. Likewise, the government in Pakistan recently blocked a Washington-based website, www.satribune.com, which can also be accessed using a proxy server.”