|
|
|
Token Ring and Token Bus Networking Technology |
|
|
|
|
|
IEEE 802.5 |
|
Token: 3 bytes
“Permission to send” |
|
Early Systems |
|
IBM |
|
Apollo Workstations |
|
Bay Networks (now Netgear/Nortel) |
|
|
|
|
|
Physical “Star”,
Logical “Ring” |
|
MAU: Multi-station
Access Unit |
|
Localizes
connections
(ease of Maintenance) |
|
Automatic bypass of unused ports |
|
|
|
|
|
|
|
|
j & k bits: Differential Manchester code
violations |
|
ED: j k 1 j k 1 0 e (error = 1) |
|
|
|
|
P: priority |
|
T: token (0- frame, 1- token) |
|
R: reserve |
|
M: monitor (1- active monitor removes frame) |
|
|
|
|
|
|
|
|
|
|
Defined for factory automation LANs |
|
Not widely used (Ethernet performance adequate) |
|
Notes