Failover and Route Redundancy Solution Guide

This Solution Guide serves as a technical reference for configuring failover and route redundancy in Poly Voice Software (PVOS) and Poly UC Software (UCS). It outlines the necessary configurations to ensure service continuity during network interruptions or maintenance. The guide details various aspects, including DNS query behaviors, the use of NAPTR, SRV, and A records, and methods for mitigating DNS failures. It provides specific instructions on dynamic DNS cache restoration and static DNS cache usage, which are crucial for maintaining operational integrity when DNS queries fail. Additionally, the document explains the failover process, including the definitions of key terms such as failover, failback, and fallback. It also discusses the limitations of SIP response codes in failover scenarios and the configuration of re-registration on failover. The guide is applicable to several Poly phone models, including the VVX, CCX, and Trio series, and supersedes previous advisories on related topics.