SIGNIFICANT CUSTOMERS, CONCENTRATION OF CREDIT RISK AND GEOGRAPHIC INFORMATION Product Revenues by the Three Product Lines (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014 product_line	Sep. 30, 2013	Sep. 30, 2012
Revenue from External Customer [Line Items]
Number of product lines									3
Product revenues	$ 27,007	$ 26,012	$ 24,869	$ 24,863	$ 26,455	$ 26,285	$ 24,689	$ 23,905	$ 102,751	$ 101,334	$ 109,920
Ethernet switching
Revenue from External Customer [Line Items]
Product revenues									50,914	38,675	32,607
Connectivity
Revenue from External Customer [Line Items]
Product revenues									41,017	42,885	52,933
Transport processing
Revenue from External Customer [Line Items]
Product revenues									$ 10,820	$ 19,774	$ 24,380