Streams networks, management

Point Sources Under Water Scarcity Managing the Stream Network... 

As depicted in Fig. 3, the B-ISDN ATM reference model has different layers and a different structure as compared to the OSI model. While the OSI model is two dimensional, the ATM model is three dimensional. ATM s physical layer corresponds to both the physical and data link layer of the OSI model. The physical layer deals with the physical transmission of the bit stream and therefore depends on the physical medium used. Copper cable or fiber optics can be used for ATM. Above the physical layer is the ATM layer that deals with flow control, virtual circuit management, and cell header generation. The ATM layer is functionally equivalent to the OSI data link and network layers. On top of the ATM layer sits the ATM adaptation layer (AAL) that supports the different ATM services. AAL lays somewhere between the transport and session layers in the OSI model and provides assembly and reassembly of packets that are larger than a cell. Four different services are currently defined for ATM, resulting in four different AAL classes. AALl supports circuit... 

---