Under normal circumstances, I would agree with you QBZappy, my the OP stated that he connected the OBi device
directly to his modem, which would rule out the problem being his router. That being said, I do not have any idea why he might be having this intermittent problem, unless his from time to time there is an intermittent glitch with his ISP broadband signal or a change in his Public WAN IP.
Is their a Static IP assigned to the OBi? Are you using GV as the provider (incoming/outgoing)? Are there any pattern to this intermittent problem or is it purely random?
chief3202,
For some reason routers seem to be a source of many problems concerning issues with the OBi. On this forum many people have installed Tomato firmware on their routers and then everything seems to work. I think your router model is supported by Tomato firmware. It might save you a lot of grief if you simply install what is arguably a superior firmware on the router and be done with these annoyances once and for all.