Montreal Protocol adopted, but not in force). As a result of the international agreement, the ozone hole in Antarctica is slowly recovering. Climate projections indicate that the ozone layer will return to 1980 levels between 2050 and 2070. Due to its widespread adoption and implementation it has been hailed as an example of exceptional international co-operation, with Kofi Annan quoted as saying that "perhaps the single most successful international agreement to date has been the Montreal Protocol". In comparison, effective burden sharing and solution proposals mitigating regional conflicts of interest have been among the success factors for the ozone depletion challenge, where
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