One option of an Lotus Sametime Unified Telephony redundant system is when two computing nodes are geographically co-located.
Geographically Co-Located Redundant System
Each node has six Ethernet links that are paired and bonded to support three redundant connections from each node. These connections are designated in the figure as follows:
OAM&P: Path A represents the primary communication path; path a represents its backup path.
Signaling: Path B represents the primary communication path; path b represents its backup path.
Billing/CDR: Path C represents the primary communication path; path c represents its backup path.
For example, Port A on node 1 serves as a primary communication path for OAM&P; port a on node 1 acts as a backup when the primary port fails.
The following are also present:
A link, known as the remote access connection, provides the ability to remotely power down and reset a node; it also permits communication with the partner node to verify its status, as described for x3650 T and FSC PRIMERGY RX 330 S1Parent topic: Cluster Redundancy
Two additional links, which are used for communication between the two nodes (also referred to as cluster interconnect signaling).
An optional survival authority.