Division 3.1 Network layout

The VIS architecture makes use of centralised services, which are accessible from the different Member States. For resiliency purposes these centralised services are duplicated to two different locations namely Strasbourg, France, hosting the principal CS-VIS, central unit (CU) and St Johann im Pongau, Austria, hosting the backup CS-VIS, backup central unit (BCU) in accordance with Commission Decision 2006/752/EC of 3 November 2006 establishing the sites for the Visa Information System during the development phase^f1.

The principal and backup central units shall be accessible from the different Member States via network access points – an LNI and a BLNI – interconnecting their national system to the CS-VIS.

The connection between the principal CS-VIS and the backup CS-VIS shall be open for any new future architectures and technologies and shall allow for the continuous synchronisation between the CU and BCU.