looked at those, neither of those solutions will fit budget: the SRP-based setup would. By "not supported" do you mean "not supported" or "won't work"? The SRP500 product overview has "system-level testing and validation" saying "SIP trunking for UC 500 and SPA9000".
The price difference between the SRP and the SR520/ATA combination is just too great: I think the only way I could get it working anywhere close to budget using either of the two configs that are supported is if a PC attached to the SPA525G2 can use the phone's VPN for connecting to the office network, with the same SNMP capabilities as the SRP. Not looking likely ....
