If we are designing a cluster with one subscriber being in a remote Location. For remote location, Local subscriber can be a primary Call Manager, and backup Call Manager could be another subscriber in data center. Is there any need to have a SRST or CME-SRST in a remote location. I don't see any real benefit. The only time SRST/CME-SRST would have any significance if both Local Subscriber and the IP WAN go down at the same time.