If the default fall-back delay is not acceptable for your architecture you can use the following advisory documents from Polycom:




Below you can find an example of this recommendations applied on a live environment:


  1. Servers -03

  2. Ethernet Switch -01

  3. IP phone with DNSSRV functionality -02

  4. FXS Gateway with DNSSRV Functionality -01

Setup Diagram & Configuration-


Step 1- Enable the Unmanaged Service in DNS Option as shown below


As an alternative in later versions of Sipxcom you could use custom records to edit a new entry in DNS configuration

Or you can simply use an external BIND server.

Step 2 - Edit priority according to below diagram

Step 3 - Set TTL parameter -same value for both servers





Special thanks to Amit Kansal and Rakesh Panwar who tested and implemented this scenario