Information Security Systems Installations Ltd. (ISSI) Delivering project services for ICT infrastructure in the defence and secure government environments. ISSI Ltd delivers project services from ICT infrastructure design and installation services, surveys for installations, standards compliance and asset management We have delivered some of the most innovative secure ICT office and NER/Data Centre spaces in the UK. Let us help you secure your systems integrity. Our designers can walk you through your project requirements, helping you to design and install secure structured cabling systems, electrical and security systems.