You’re welcome. I forgot to answer the second part of your question:
Yes you can use such a call survival device in combination with HAAst. But we do not recommend it. Such a product does nothing for real life failure scenarios, but adds new single points of failure. (Nothing to gain, lots to lose). You are better off using one of the techniques described above to keep calls up.
If you want to build your own open source version of the commercial product above have a look at https://telium.io/topic/keeping-calls-up-when-cluster-switches-to-backup-node/.
If you qualify for the OEM edition of HAAst then let HAAst perform the full call continuity function for you.
