http://www.legislation.gov.uk/eur/2012/1273/article/4Council Regulation (EU) No 1273/2012 of 20 December 2012 on migration from the Schengen Information System (SIS 1+) to the second generation Schengen Information System (SIS II) (recast)Council Regulation (EU) No 1273/2012Council Regulation (EU) No 1273/2012 of 20 December 2012 on migration from the Schengen Information System (SIS 1+) to the second generation Schengen Information System (SIS II) (recast)2020-12-10King's Printer of Acts of Parliamenthttps://webarchive.nationalarchives.gov.uk/eu-exit/https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R1273texttext/xmlen2012-12-20
Article 4Technical components of the interim migration architecture

In order to ensure the migration from SIS 1+ to SIS II, the following components shall be made available to the extent necessary:

(a)

the C.SIS and the connection to the converter;

(b)

the communication infrastructure for SIS 1+ allowing the C.SIS to communicate with the N.SIS;

(c)

the N.SIS;

(d)

Central SIS II, NI-SIS and the communication infrastructure for SIS II allowing the Central SIS II to communicate with N.SIS II and the converter;

(e)

the N.SIS II;

(f)

the converter.