Segment Reporting and Geographic Information (Statement of Operations Information by Business Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Gross profit
Gross profit	$ 14,787	$ 14,372	$ 13,312	$ 12,681	$ 16,536	$ 14,648	$ 16,682	$ 13,808	$ 55,152		$ 61,674		$ 67,741
Depreciation expense
Depreciation expense									1,448		1,266		1,155
Operating income (loss)
Operating income (loss)	(2,838)	(2,120)	(1,244)	(3,645)	(1,294)	471	(781)	(2,113)	(9,847)		(3,717)		1,615
Provision (benefit) for income taxes	1,077	(869)	296	(1,517)	1,267	(1,132)	(151)	(1,175)	(1,013)		(1,191)		(468)
Operating Segments [Member]
Gross profit
Gross profit									55,157		62,082		67,940
Operating income (loss)
Operating income (loss)									5,610		10,575		13,392
Network Equipment segment [Member]
Gross profit
Gross profit									43,325		49,423		52,222
Depreciation expense
Depreciation expense									1,022		843		784
Operating income (loss)
Operating income (loss)									1,096		4,539		5,559
Provision (benefit) for income taxes									(2,468)		(3,289)		(3,364)
Network Integration segment [Member]
Gross profit
Gross profit									11,832		12,659		15,718
Depreciation expense
Depreciation expense									234		243		312
Operating income (loss)
Operating income (loss)									4,514		6,036		7,833
Provision (benefit) for income taxes									1,455		2,098		2,896
Corporate Unallocated and Intersegment Adjustments [Member]
Gross profit
Gross profit									(5)	[1]	(408)	[1]	(199)	[1]
Operating income (loss)
Operating income (loss)									(15,457)	[1]	(14,292)	[1]	(11,777)	[1]
Corporate [Member]
Depreciation expense
Depreciation expense									192		180		59
Operating income (loss)
Provision (benefit) for income taxes									$ 0		$ 0		$ 0

[1] Adjustments reflect the elimination of intersegment revenue and profit in inventory.