# Commission Decision of 16 March 2007 laying down the network requirements for the Schengen Information System II (1st pillar) (notified under document number C(2007) 845) (Only the Bulgarian, Czech, Dutch, German, Estonian, Finnish, French, Greek, Hungarian, Italian, Latvian, Lithuanian, Maltese, Polish, Portuguese, Romanian, Slovak, Slovenian, Spanish, and Swedish text is authentic) (2007/170/EC), Division 6: Generic services

Extent: E+W+S+N.I.

Apart from the dedicated network and security services, the Communication Infrastructure must also offer generic services.
Dedicated services must be implemented within both central units, for redundancy purposes.
The following optional generic services must be present in the Communication Infrastructure:
Service
Additional information
DNS
Currently the failover procedure for switching from the CU to the BCU in case of network failure is based on changing the IP address within the generic DNS server.
E-mail relay
Using a generic e-mail relay might be useful for standardising the e-mail set-up for the different Member States and, contrary to a dedicated server, does not use up any network resources from the CU/BCU.
E-mails using the generic e-mail relay must still comply with their security template.
NTP
This service may be used to synchronize the clocks of network equipment.

---
Source: https://www.legislation.gov.uk/eudn/2007/170/annex/division/6 (the official version)
Page: https://openlegislation.uk/eu-decision-2007-170/annex/division-6
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.