Internet telephony software specialist SIPquest said Monday it and wireless network equipment maker Nortel Networks are <A HREF="http://news.zdnet.com/2110-1035_22-5602657.html?tag=zdnn.alert">adding Internet-telephony capabilities</A> to Research In Motion's BlackBerry, Sony Ericsson's P900 and other smart phones. The Net-phone user interface will come from Ottawa-based SIPquest, and Nortel's MCS 5200, which is network operator equipment for video conferencing, online collaboration and other advanced telephone services.