Service Definition

SASE is a secure communications service from the network edge to the cloud edge. It is integrated across all the layers of the service; the physical, data link, network, transport, session, presentation, and application layers, as defined by Open Systems Interconnection (OSI). Previous generations of solutions addressed network connectivity at the network layer with some regard to data link layer requirements. Security generally focuses on either the application layer or the network layer, though many attempts have been made over the past 20 years to integrate the data link with the security model. SASE intends to ensure security across all the layers by starting with a Zero-Trust Framework (ZTF). In Chapter 16, SASE Trust, ZTF will be explained further, but for now, we can explain it as follows: if security starts from a deny all, each and every layer must be validated before the next, security becomes pervasive in the service.

SASE does not create any of its...