Token ring issues
Clock synchronization
- For physical rings input timing jitter requires each node to generate its own clock for transmitting
- Clock must be closely synchronized to the clock of the preceding node on the ring to keep from having to add sync marks or buffer a lot of data
Maintaining the single token
- Loss of token or multiple tokens break rings
- Rings needs to be monitored for token failures
- Recovery requries a unique node to generate a new token -- election
Preserving the ring connectivity
- Failure of a single node breaks the ring
- Bypass repeaters/relays
- Dual attachment rings