Segments - Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2013	Apr. 30, 2012	Jul. 31, 2012
Segment Reporting Information [Line Items]
Revenue	$ 5,102	$ 4,961	$ 16,077	$ 16,864
Income (loss) from operations	91	(88)	46	444
Total assets	12,278	12,572	12,278	12,572	13,606
Capital expenditures	59	90	219	163
Allowance for doubtful accounts	284	375	284	375	555
Depreciation and amortization	28	25	71	77
Communications Systems and Services [Member]
Segment Reporting Information [Line Items]
Revenue	323	360	983	1,266
Income (loss) from operations	(83)	(126)	(387)	(463)
Total assets	1,661	2,008	1,661	2,008
Capital expenditures	0	0	0	0
Allowance for doubtful accounts	106	307	106	307
Depreciation and amortization	1	1	4	4
Telephony Products [Member]
Segment Reporting Information [Line Items]
Revenue	2,871	2,980	8,353	9,813
Income (loss) from operations	111	156	251	855
Total assets	7,262	7,372	7,262	7,372
Capital expenditures	3	63	122	81
Allowance for doubtful accounts	17	16	17	16
Depreciation and amortization	13	6	34	24
Puerto Rico [Member]
Segment Reporting Information [Line Items]
Revenue	1,908	1,621	6,741	5,785
Income (loss) from operations	63	(118)	182	52
Total assets	3,355	3,192	3,355	3,192
Capital expenditures	56	27	97	82
Allowance for doubtful accounts	161	52	161	52
Depreciation and amortization	14	18	33	49
Total [Member]
Segment Reporting Information [Line Items]
Revenue	5,102	4,961	16,077	16,864
Income (loss) from operations	91	(88)	46	444
Total assets	12,278	12,572	12,278	12,572
Capital expenditures	59	90	219	163
Allowance for doubtful accounts	284	375	284	375
Depreciation and amortization	$ 28	$ 25	$ 71	$ 77