Protocols
Token Passing (IBM)
- All blocks of data carried around the network with a source and destination address
- Traffic is guided physically from unit to unit around the ring
- IEEE 802.5; ISO IS 8802-5
Token Bus
- Traffic is guided on a common data bus, which directly connects all units in the network
- All units are part of an organized logical sequence
- All units at any point in time know the address of the unit before and after in logical sequence.
CSMA/CD (ethernet)
- All units connected to the common bus can come in at any point in time after the unit has tested and found out no one else is using the network.
- When collisions happen, both units resend the data after a short break.