olemus
eriotstarbeline piirangutega sidevõrk
= a communications network that is used for a specific purpose

ülevaateid
https://www.igi-global.com/dictionary/open-vs-closed-network/21242
https://www.ninjaone.com/it-hub/endpoint-security/closed-network/
https://resources.sei.cmu.edu/asset_files/presentation/2011_017_101_57167.pdf

näiteid
- SWIFTNet
- JWICS
- NIPRNet