Acme Packet (NASDAQ:APKT) reduces guidance, with 2011 revenue of $308 million - $310 million against consensus of $318 million. EPS are brought down to $1.03-$1.05 against consensus of $1.14.

Acme Packet, Inc. President and Chief Executive Officer Andy Ory said, “Our results were impacted by uncertainty in the North American service provider market. Outside of the North American service provider market, Acme Packet continued to perform very well – particularly in our enterprise business as well as in our Europe and Latin America businesses. Looking ahead, we believe we are very well positioned to leverage the broad, multi-year, secular growth drivers associated with the global transition from TDM to IP for real time communications like voice and video.”

Acme Packet is causing widespread weakness in networking equipment names, as the firm’s soft guidance and remarks about poor demand from North American telcos incite concerns about a less-than-robust 2012 capex environment.

These stocks are getting crushed on the news:

Juniper Networks, Inc. (NYSE:JNPR): JNPR shares recently traded at $20.66, down $0.38, or 1.81%. They have traded in a 52-week range of $16.67 to $45.01. Volume today was 7,076,541 shares versus a 3-month average volume of 9,980,520 shares. The company’s trailing P/E is 21.77, while trailing earnings are $0.95 per share.

F5 Networks, Inc. (NASDAQ:FFIV): FFIV shares recently traded at $104.88, down $1.06, or 1%. They have traded in a 52-week range of $69.01 to $145.76. Volume today was 2,169,647 shares versus a 3-month average volume of 1,965,600 shares. The company’s trailing P/E is 35.43, while trailing earnings are $2.96 per share.

Riverbed Technology, Inc. (NASDAQ:RVBD): RVBD shares recently traded at $25.68, up $0.97, or 3.93%. They have traded in a 52-week range of $12.57 to $44.70. Volume today was 3,318,830 shares versus a 3-month average volume of 4,877,530 shares. The company’s trailing P/E is 75.75, while trailing earnings are $0.34 per share.

Alcatel-Lucent (NYSE:ALU): ALU shares recently traded at $1.58, down $0.12, or 7.06%. They have traded in a 52-week range of $1.39 to $6.63. Volume today was 8,459,180 shares versus a 3-month average volume of 22,542,100 shares. The company’s trailing P/E is 5.11, while trailing earnings are $0.31 per share.

LM Ericsson Telephone Co. (NASDAQ:ERIC): ERIC shares recently traded at $9.94, down $0.45, or 4.33%. They have traded in a 52-week range of $8.83 to $15.44. Volume today was 5,924,999 shares versus a 3-month average volume of 5,095,580 shares. The company’s trailing P/E is 14.43, while trailing earnings are $0.69 per share.

Cisco Systems, Inc. (NASDAQ:CSCO): CSCO shares recently traded at $18.99, up $0.36, or 1.93%. They have traded in a 52-week range of $13.30 to $22.34. Volume today was 35,585,671 shares versus a 3-month average volume of 51,167,700 shares. The company’s trailing P/E is 16.40, while trailing earnings are $1.16 per share.

Aruba Networks, Inc. (NASDAQ:ARUN): ARUN shares recently traded at $18.00, down $0.1, or 0.55%. They have traded in a 52-week range of $16.20 to $36.40. Volume today was 2,041,431 shares versus a 3-month average volume of 2,908,080 shares. The company’s trailing P/E is 30.72, while trailing earnings are $0.59 per share.

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