Annual report pursuant to Section 13 and 15(d)

Restructuring Charge (Details Textual)

Restructuring Charge (Details Textual) (USD $)	3 Months Ended							12 Months Ended
Restructuring Charge (Details Textual) (USD $)	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Restructuring Charge (Textual) [Abstract]
Restructuring	$ 3,188,000us-gaap_RestructuringCharges	$ (2,000)us-gaap_RestructuringCharges	$ 57,000us-gaap_RestructuringCharges	$ 62,000us-gaap_RestructuringCharges	$ 38,000us-gaap_RestructuringCharges	$ 169,000us-gaap_RestructuringCharges	$ 66,000us-gaap_RestructuringCharges	$ 3,243,000us-gaap_RestructuringCharges	$ 335,000us-gaap_RestructuringCharges	$ 149,000us-gaap_RestructuringCharges
Accrued restructuring	1,161,000us-gaap_RestructuringReserveCurrent			57,000us-gaap_RestructuringReserveCurrent				1,161,000us-gaap_RestructuringReserveCurrent	57,000us-gaap_RestructuringReserveCurrent
Accrued restructuring non-current	1,642,000us-gaap_RestructuringReserveNoncurrent							1,642,000us-gaap_RestructuringReserveNoncurrent
Payments for Restructuring								425,000us-gaap_PaymentsForRestructuring	284,000us-gaap_PaymentsForRestructuring	756,000us-gaap_PaymentsForRestructuring
Unpaid balance of restructuring charges	2,804,000us-gaap_RestructuringReserve			57,000us-gaap_RestructuringReserve				2,804,000us-gaap_RestructuringReserve	57,000us-gaap_RestructuringReserve	6,000us-gaap_RestructuringReserve	613,000us-gaap_RestructuringReserve
4Q15 Restructuring [Member]
Restructuring Charge (Textual) [Abstract]
Restructuring and Related Cost, Number of Positions Eliminated								17
Restructuring	3,200,000
Impairment of Leasehold	2,700,000
Kentrox [Member]
Restructuring Charge (Textual) [Abstract]
Restructuring and Related Cost, Number of Positions Eliminated									12
Restructuring								55,000	335,000
Payments for Restructuring									278,000
Cumulative Restructuring								390,000
Noran Tel Restructuring [Member]
Restructuring Charge (Textual) [Abstract]
Restructuring and Related Cost, Number of Positions Eliminated										35
Restructuring										149,000
Cumulative Restructuring										424,000
Employee Related Restructuring Cost [Member]
Restructuring Charge (Textual) [Abstract]
Restructuring								337,000	335,000	89,000
Accrued restructuring				57,000					57,000
Payments for Restructuring								379,000	284,000	644,000
Unpaid balance of restructuring charges	$ 15,000			$ 57,000				$ 15,000	$ 57,000	$ 6,000	$ 561,000