1 | (1) Physical: passes bit stream between computer and network; defines voltage used, the data transmission timing, handshaking requirements; EIA-RS232, RS449, Ethernet, token ring, FDDI |
2 | (2) Data Link: provides reliable data transfer between computer and network; packages data into data frames; HDSL, SDSL, ATM, FR, NDIS, ODI |
3 | (3) Network: sets up and maintains connections; establishes virtual circuits between computers; IP, X.25, IPX |
4 | (4) Transport: provides control of quality of service; TCP, UDP, SPX, NetBEUI |