One of the building blocks in the Government Backbone Network is the Government Communication Network (GCN) which links up the bureaux of the Government Secretariat with all departmental headquarters for the purposes of information and mail exchange through electronic means.

The initial phase to link up the office automation Local Area Networks in the Government Secretariat via fibre-optic telephone lines was completed in early 1996. The second phase of extending the network to 22 government departments was completed in June 1998, and the remaining departments were linked up at the end of the year 2000. A schematic configuration is presented in the following diagram.

The GCN functions as the central hub of an electronic post office providing a central directory through which e-mail is stored and forwarded. It operates on a 24-hour basis providing functions such as e-mail and document exchange, short message service, instant messaging service, directory synchronisation, and other frequently used services such as bulletin boards.