Shorting premium priced but high-quality businesses is dangerous. Just ask anyone on the wrong side of Acme Packet (Nasdaq: APKT) today.

Last night, the market's leading provider of session border controllers reported financial results that beat the Street's expectations and raised its 2011 outlook. Management now expects $1.05 in non-GAAP per-share earnings on $300 million in revenue. Earlier estimates called for $0.99 to $1 on $286 million to $287 million in revenue.

For the quarter, Acme Packet said revenue soared 70% to $70.2 million. Non-GAAP profits more than doubled to $0.26 a share. Analysts were looking for $60.8 million and $0.23 a share, respectively.

Big-money investors apparently see an opportunity that analysts don't. Shares of Acme Packet are up more than 18% on heavy volume as I write this. The move more than makes up for last month's cloud computing sell-off, instigated by a less-than-perfect earnings report from F5 Networks (Nasdaq: FFIV).

Acme's competitive position is also getting stronger. Co-founder and CEO Andy Ory told investors during yesterday's earnings conference call that emerging networks built entirely on the Web will "drive further infrastructure investments requiring our solutions."

He referenced videoconferencing and unified communications and collaboration, specifically. Ory's point? Advanced telecom features are only now becoming available on VoIP networks, and those networks need SBCs.

As the guy who picked Acme Packet for Motley Fool Rule Breakers, I think he's right. Networking and telecom infrastructures aren't like chip architectures. Cisco Systems (Nasdaq: CSCO) and Juniper Networks (Nasdaq: JNPR), though strong growers, have yet to convince IT managers that one box can handle everything a network needs.

Demand persists for F5's load balancers, Acme Packet's SBCs, and Riverbed Technology's (Nasdaq: RVBD) wide-area-network optimizers because each plays a role in making enterprise networks and the public Internet faster and more efficient. Cisco and Juniper can't do the job alone.

But that's just my take. Now it's your turn to weigh in. Will competitive threats end the Acme Packet growth story prematurely? Please vote in the poll below and then leave a comment to explain your thinking.