I have had 3102 for two years now, and has been using SIP connection all the time with no problems.
Today I tried to add PSTN that is provided by Comcast ARRIS modem. SPA won't detect line as active. I implemented dialing rules and am getting busy tone if it is routed yo PSTN. If I disconnect the internet cable from SPA it does not have any choice and only then will connect to the analog line'. In this case it works fine. What do I have to do so I get borh connections recognized and working obeying dialing rules. I called techsupport but they would not help me because I have had the device longer than a year. I assume that voltage provided to PSTN connector is low (not even close to standard 48v) and that is cause of the trouble.