Given: a very straight-forward small network with one SBS2003 server connected to a single subnet. The SBS server handles DHCP and DNS for this network. A Cisco 800 router is also connected to that subnet and handles VPN, NAT and Firewall. Now, we would like to embed a UC540 and ESW520 swich in this network. The ESW520 replaces an older switch and the UC540 will only be used for telephony/voice purpose. So we have configured the UC540 using the wizards and we have disabled several services like firewall, DHCP (for data), NAT, WAN interface (gateway). Also we have changed the IP subnet for the data VLAN from 192.168.10.x into 192.168.11.x because subnet 11 is the current running subnet in our network.
Now we encounter problems with all SPA504G phones. They continuously are downloading configs (in loops). It does not matter if a phone is connected directly to the UC540 or to the ESW520 switch. We also have two 7931 phones, they do not have that problem.
1) Is there a manual, blueprint or sample config which we can learn from on how to implement a UC540 in a SBS environment?
2) Any idea why the SPA phones encounter connection problems and the 7931 phones don't?
Hope to find some leads or answers here. Thanks in advance for taking the time to look at this!