1 - Implementing high availability
- Monitoring and automatic selection of routes
- Automatic monitoring of the status of modems and equipment
- Using standard protocol
2 - Routing example for ModBus applications
- IP encapsulation of the serial protocol
- IP routing based on the serial address
3 - Example of a fully redundant network
Redundant master modem (“Ethernet redundancy”) to one or more redundant “station” modems
Master modems and redundant stations modems:
- VRRP (i.e. Virtual Router Redundancy Protocol) : if the active modem fails, the standby modem becomes active.
- By default, the traffic between DTE-A and DTE-B passes through the M1 and M3 modems.
- If M1 becomes inaccessible: the traffic between DTE-A and DTE-B goes through the M2 and M3 modems.
- If M3 becomes inaccessible: the traffic between DTE-A and DTE-B goes through M2 and M4 modems.
- If M1 becomes accessible again: the traffic between DTE-A and DTE-B passes through modems M1 and M4.