001 - Document - Document and Entity Information link:presentationLink link:definitionLink link:calculationLink 002 - Statement - CONSOLIDATED BALANCE SHEETS link:presentationLink link:definitionLink link:calculationLink 003 - Statement - CONSOLIDATED BALANCE SHEETS (Parentheticals) link:presentationLink link:definitionLink link:calculationLink 004 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) link:presentationLink link:definitionLink link:calculationLink 005 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) link:presentationLink link:definitionLink link:calculationLink 006 - Disclosure - Basis of Presentation link:presentationLink link:definitionLink link:calculationLink 007 - Disclosure - Fair Value Measurements link:presentationLink link:definitionLink link:calculationLink 008 - Disclosure - Computation of Earnings per Share link:presentationLink link:definitionLink link:calculationLink 009 - Disclosure - Stock-Based Compensation link:presentationLink link:definitionLink link:calculationLink 010 - Disclosure - Business Segments link:presentationLink link:definitionLink link:calculationLink 011 - Disclosure - Recent Accounting Pronouncements link:presentationLink link:definitionLink link:calculationLink 012 - Disclosure - Gain on Sale of Patent Assets link:presentationLink link:definitionLink link:calculationLink 013 - Disclosure - Income from patent arrangement link:presentationLink link:definitionLink link:calculationLink 014 - Disclosure - Income Taxes link:presentationLink link:definitionLink link:calculationLink 015 - Disclosure - Discontinued Operations link:presentationLink link:definitionLink link:calculationLink 016 - Disclosure - DSL Service Assurance Software Exit link:presentationLink link:definitionLink link:calculationLink 017 - Disclosure - Fair Value Measurements (Tables) link:presentationLink link:definitionLink link:calculationLink 018 - Disclosure - Computation of Earnings per Share (Tables) link:presentationLink link:definitionLink link:calculationLink 019 - Disclosure - Stock-Based Compensation (Tables) link:presentationLink link:definitionLink link:calculationLink 020 - Disclosure - Business Segments (Tables) link:presentationLink link:definitionLink link:calculationLink 021 - Disclosure - Discontinued Operations (Tables) link:presentationLink link:definitionLink link:calculationLink 022 - Disclosure - DSL Service Assurance Software Exit (Tables) link:presentationLink link:definitionLink link:calculationLink 023 - Disclosure - Fair Value Measurements - Assets measured at fair value on a recurring basis and whose carrying values approximate their respective fair values (Details) link:presentationLink link:definitionLink link:calculationLink 024 - Disclosure - Fair Value Measurements (Detail Textuals) link:presentationLink link:definitionLink link:calculationLink 025 - Disclosure - Computation of Earnings per Share - Summary of net income per share (Details) link:presentationLink link:definitionLink link:calculationLink 026 - Disclosure - Computation of Earnings per Share (Detail Textuals) link:presentationLink link:definitionLink link:calculationLink 027 - Disclosure - Stock-Based Compensation - Summary of stock-based employee compensation expenses (Details) link:presentationLink link:definitionLink link:calculationLink 028 - Disclosure - Stock-Based Compensation (Detail Textuals) link:presentationLink link:definitionLink link:calculationLink 029 - Disclosure - Business Segment - Results of operations for reportable segments (Details) link:presentationLink link:definitionLink link:calculationLink 030 - Disclosure - Business Segments - Revenues were generated from following geographic regions (Details 1) link:presentationLink link:definitionLink link:calculationLink 031 - Disclosure - Gain on Sale of Patent Assets (Detail Textuals) link:presentationLink link:definitionLink link:calculationLink 032 - Disclosure - Income from patent arrangement (Detail Textuals) link:presentationLink link:definitionLink link:calculationLink 033 - Disclosure - Income Taxes (Detail Textuals) link:presentationLink link:definitionLink link:calculationLink 034 - Disclosure - Discontinued Operations - Income from discontinued operations attributable to the DSL service assurance hardware product line (Details) link:presentationLink link:definitionLink link:calculationLink 035 - Disclosure - DSL Service Assurance Software Exit - A rollforward of our exit costs liability accounts (Details) link:presentationLink link:definitionLink link:calculationLink 036 - Disclosure - DSL Service Assurance Software Exit (Detail Textuals) link:presentationLink link:definitionLink link:calculationLink