Segments - Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012	Jul. 31, 2012
Segment Reporting Information [Line Items]
Revenue	$ 5,241	$ 5,673	$ 10,975	$ 11,903
Net (loss) income from operations	(145)	178	(45)	532
Total assets	13,091		13,091		13,606
Allowance for doubtful accounts	309		309		555
Depreciation and amortization			43	48
Communications Systems and Services [Member]
Segment Reporting Information [Line Items]
Revenue	312	531	660	906
Net (loss) income from operations	(157)	(170)	(304)	(337)
Total assets	1,812	2,322	1,812	2,322
Capital expenditures
Allowance for doubtful accounts	105	307	105	307
Depreciation and amortization	1	2	3	3
Telephony Products [Member]
Segment Reporting Information [Line Items]
Revenue	2,501	2,982	5,482	6,833
Net (loss) income from operations	(10)	204	140	699
Total assets	7,469	7,981	7,469	7,981
Capital expenditures	12	18	119	18
Allowance for doubtful accounts	23	16	23	16
Depreciation and amortization	11	7	21	14
Puerto Rico [Member]
Segment Reporting Information [Line Items]
Revenue	2,428	2,160	4,833	4,164
Net (loss) income from operations	22	144	119	170
Total assets	3,810	3,114	3,810	3,114
Capital expenditures		45	41	55
Allowance for doubtful accounts	181	60	181	60
Depreciation and amortization	5	17	19	31
Total [Member]
Segment Reporting Information [Line Items]
Revenue	5,241	5,673	10,975	11,903
Net (loss) income from operations	(145)	178	(45)	532
Total assets	13,091	13,417	13,091	13,417
Capital expenditures	12	63	160	73
Allowance for doubtful accounts	309	383	309	383
Depreciation and amortization	$ 17	$ 26	$ 43	$ 48