Egypt’s largest ISPs shut off their networks Thursday, making it impossible for traffic to get to websites hosted in Egypt or for Egyptians to use e-mail, Twitter or Facebook. The regime of President Hosni Mubarak also ordered the shut down of mobile phone networks, including one run by the U.K.-based Vodafone, all in an attempt to undermine the growing protests over Mubarak’s autocratic rule of the country.
Internet is a decentralized network with some special nodes running the BGP to interconnect sub-networks, switching off these nodes in a country will lead to a national Internet blackout. This is an appealing action for some politicians accostumed “to handle” traditional mass media and unavailable to handle with the power of the new media and social networks.
The Border Gateway Protocol (BGP) is the protocol backing the core routing decisions on the Internet. It maintains a table of IP networks or ‘prefixes’ which designate network reachability among autonomous systems (AS). It is described as a path vector protocol. BGP does not use traditional Interior Gateway Protocol (IGP) metrics, but makes routing decisions based on path, network policies and/or rulesets. For this reason, it is more appropriately termed a reachability protocol rather than routing protocol.
Some iniciatives are trying to generate a parallel distributed network, i.e. Freenet in order to avoid situations like this one in the future.
Freenet is free software which lets you anonymously share files, browse and publish “freesites” (web sites accessible only through Freenet) and chat on forums, without fear of censorship. Freenet is decentralised to make it less vulnerable to attack, and if used in “darknet” mode, where users only connect to their friends, is very difficult to detect. Communications by Freenet nodes are encrypted and are routed through other nodes to make it extremely difficult to determine who is requesting the information and what its content is.
Google, Twitter and SayNow have been working during the last days in a project to allow people send tweets using a voicemail service.
UPDATE (via microsiervos) ¿Sabes lo que pasa cuando intentas bloquear Internet en todo un país?