Polycom realpresence 1800 Administrator's Manual page 1038

All Front End (FE) servers in the pool register themselves in DNS server with the same FQDN but different
IP addresses (both IPv4 and IPv6 are supported).
The Collaboration Server supports both FE Load Balancing and FE Failover.
● FE Load Balancing, is implemented by the DNS server. Each DNS query is replied by the DNS server
with different priorities, and the Collaboration Server connects with the FE with the highest priority.
● FE Failover, in case the Collaboration Server fails to communicate with the first FE in the DNS list, it
will try and gain connection with the second FE in the list, and so on.
The Collaboration Server presents the FE IP connected in the Default IP Service Properties > SIP Servers
tab as shown below:
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Appendix H - Deployment Into Microsoft Environments
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