I installed Cisco UC500 router - the unified communication commander for our company since mid 2010. I use the switch for both voice and data. We have 4 sip trunks and the switch is connected to an APC ups. We wired our office with 2 separate physical networks, one for data and the other for voice. We have 10 extensions of using Cisco 7945 handsets + Cisco SF 300-24p PoE hub. Qos is enabled and everything is working fine except the Cisco UC500 has intermittent problem rebooting by itself of say once a week. You could imagine the situation that our phone conversation is becoming choppy and being cut off during office hours.

We have the Cisco service contract and we try many times to update to the latest firmware, but problem persists. Anyone could give us cures to our problem?? Please advise.