Shares of Acme Packet (NASDAQ:APKT) jumped nearly 12% on heavy volume in one session in early January thanks to a Stifel Nicolaus upgrade to Buy with a price target of $27. The firm thinks carriers are finally starting to firm up the timing of their Voice-over-LTE (VoLTE) projects which is a big positive for Acme Packet. With new rollouts from Tier-1 carriers in the US expected to start in the second half of the year Acme Packet could see strong order momentum beginning in the first half. Stifel Nicolaus says its checks indicate that AT&T (NYSE:T) will begin testing ...