Question for the experts. Having problems with my Grandstream (incoming straight to voicemail, outgoing doesn't work) but my softphone clients (CSipSimple on Android) continue to work fine at home.

Prior to these problems I had my Grandstream connected to the house pots and all our regular phones continued to work just as before the switch to voipo. Is there any type of hardware device I can drop in at home that will act as a softphone/sip adapter to my house pots?

TIA.