Aastra 9133i SIP phone with Voipfone on Sky broadband with SR101 router (SOLVED)

Having moved from O2 to Sky Fibre Broadband everything looked great and fast except for my Aastra 9133i SIP phone which would connect but then drop-out a minute or two later.

I found near nothing on the web and hadn’t found my Aastra phone completely reliable before although that may have been down to my previous O2 router and slower broadband connection.

After a few hours of playing with the settings, I found a solution that is still connected after 24 hours so that works for me…

  • Use the Sky router settings out of the box, so no port forwarding needed etc. The only Router setting I used (so that I can find the Aastra on my network more easily) was to reserve a static local IP address for the Aastra 9133i from the Router’s DHCP pool.  You do this by seeing what IP address the Router has allocated the router and ‘reserving’ this for future use.Router > Advanced > LAN IP Setup
  • The Aastra 9133i Global SIP settings eventually settled down to these below…

    Pay particular attention to the SIP registration period and associated timers.
    DTMF Method of BOTH also seemed helpful
    For info: Codec preference list attributes translate to:-8 = G.711 a-Law; ptime = packetsize (millisecs); silsupp = silence suppression
  • On the Line specific settings…