Application layer. Security protocols, including Transport Layer Security, operate at this layer and play an integral component in making sure network security. This can be the abstraction layer that communicates straight with apps and defines how higher-level apps should really obtain the network to get started on an information transfer. https://themedecoration30627.goabroadblog.com/32851471/how-much-you-need-to-expect-you-ll-pay-for-a-good-cctv