power outage phone reboot

[convervoip]

The data side of the house doesn't put UPS's on the switches. When the power goes out the mid spans come up before the data switches. All of the phone say "bad router". I have to tell 300 people to unplug there phones and reboot them. Is there a way to make the phone keep trying to come up to give the data switches time to sync.

I know an answer is UPS's but it's not an option.

Thanks