Can one set up OBi100 for test run only and then switch back to the original VOIP set up without creating problems. I may also be switching ISP providers at the end of the month. on that note, does one have to reconfigure OBi again with an new ISP provider? Has anyone done this and if so, did it go relatively smoothly? :-\ Thanks in advance
You can back up your config, reset (or not) and set up the test config. When done testing, restore from the backup. I believe that passwords don't get backed up, so you will have to re-enter them manually.
If you are keeping the same router and it gets a public IP address on the WAN side in both cases, you shouldn't need to change anything when switching ISPs. However, some routers and modem/routers have quirks that require special settings for SIP, so you may need to adjust accordingly.