For a cluster redundancy with layer-3 cluster interconnect, only a layer-3 IP connection is required between the two nodes.
This option does not require spanning VLANs between the two nodes.
Lotus Sametime Unified Telephony also supports the use of low-bandwidth cluster interconnect links, which make geographically separated redundant nodes an economical option for smaller installations. However, degradation in system performance should be expected when these links are used. The performance degradation affects both call processing capabilities as well as mass provisioning times. Packet delays on the interconnect link (any values above 100-ms roundtrip time) can also cause performance degradation in mass provisioning times.
If the primary network interface (represented by CI in the figure) fails, the Linux bonding driver uses the backup interface (represented by ci in the figure).
Geographically Separated Redundant System with Layer-3 Cluster Interconnect
Parent topic: Cluster Redundancy
Cluster Redundancy with Geographic Node Separation