Commission Decision of 16 March 2007 laying down the network requirements for the Schengen Information System II (3rd pillar) (2007/171/EC)

2. General overview

The SIS II is composed of:

• the central system (hereinafter referred to as ‘the Central SIS II’) consists of:

  • a technical support function (herein after referred to as ‘CS-SIS’) containing the SIS II database. The principal CS-SIS carries out technical supervision and administration and a backup CS-SIS is capable of ensuring all functionalities of the principal CS-SIS in case of failure of this system,

  • a uniform national interface (hereinafter referred to as ‘NI-SIS’);

• a national section (hereinafter referred to as ‘N.SIS II’) in each of the Member States, consisting of the national data systems which communicate with the Central SIS II. An N.SIS II may contain a data file (hereinafter referred to as ‘national copy’), containing a complete or partial copy of the SIS II database,

• a communication infrastructure between the CS-SIS and the NI-SIS (hereinafter referred to as ‘Communication Infrastructure’) that provides an encrypted virtual network dedicated to SIS II data and the exchange of data between Sirene Bureaux.

The NI-SIS which consists of:

• one Local National Interface (hereinafter referred to as ‘LNI’) in each Member State which is the interface that physically connect the Member State to the secure communication network and contain the encryption devices dedicated to SIS II and Sirene traffic. The LNI is located at the Member State premises,

• an optional Backup Local National Interface (hereinafter referred to as ‘BLNI’) which has exact the same content and function as the LNI.

The LNI and BLNI are to be used exclusively by the SIS II system and for Sirene exchange. The specific configuration of the LNI and BLNI will be specified and agreed with each individual Member State in order to take account of security requirements, the physical location and conditions of installation, including the provision of services by the network provider, meaning the physical s-TESTA connection may contain several VPN tunnels for other systems, for example VIS and Eurodac.

• a Central National Interface (hereinafter referred to as ‘CNI’) which is an application securing access to the CS-SIS. Each Member State has separate logical access points to the CNI via a central firewall.

The Communication Infrastructure between the CS-SIS and the NI-SIS consists of:

• the network for Secure Trans-European Services for Telematics between Administrations (hereinafter referred to as ‘s-TESTA’) that provides an encrypted, virtual, private network dedicated to SIS II data and Sirene traffic.