Stephen O. Andersen protecting the stratospheric ozone layer. At EPA he rose to Deputy Director for Stratospheric Ozone Protection and then transferred to the Climate Protection Partnerships Division, where he was Director of Strategic Climate Projects until his retirement from government in 2009. The timing of Andersen’s arrival at EPA was fortuitous. 1987 proved to be a watershed moment in the effort to stop ozone depletion, which increased risks of skin cancer and threatened to wipe out crops and ecosystems, among many adverse impacts. The Montreal Protocol on Substances that Deplete the Ozone Layer was agreed on 16 September 1987 and created a
Subnetwork Access Protocol necessary to determine which protocol is to be invoked to process a service data unit delivered by the lower layer. The most common reference to SAP, including a Source Service Access Point (SSAP) and a Destination Service Access Point (DSAP) refers to the boundary between the Data Link Layer and the Network Layer. It is common to think of SAP only in terms of its use at Layer 2, specifically in its Logical Link Control (LLC) sub-layer as defined in the IEEE 802.2 standards. Link Service Access Point (LSAP) includes both Destination Service Access Point (DSAP) and Source Service Access