AltiGen Communications, Inc.

1. AltiGen Communications, Inc. Nasdaq: ATGN Jerry Fleming KBRO 10th Annual Investor ConferenceSeptember 6, 2007

2. Safe Harbor This presentation may contain forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, including, without limitation, statements regarding the continued market acceptance of our Voice over IP telephone systems, our continued success stemming from the introduction of the MAX 1000 VoIP phone system, our ability to enhance our customer experience with the goal of capturing multi-site deployments, our successful execution of our growth plan, including the continued addition of new resellers along with the implementation of our software assurance and hardware warranty programs. These statements reflect management's current expectation. However, actual results could differ materially as a result of unknown risks and uncertainties, including but not limited to, risks related to AltiGen's limited operating history. For a more detailed description of these and other risks and uncertainties affecting AltiGen's performance, please refer to AltiGen's Annual Report on Form 10-K for the fiscal year ended September 30, 2006 and all subsequent current reports on Form 8-K and quarterly reports on Form 10-Q. All forward-looking statements in this presentation are based on information available to AltiGen as of the date hereof and AltiGen assumes no obligation to update these forward-looking statements.

3. Delivering Unified Communications A leading provider of Microsoft-based Unified Communications for SMBs with a focus on multi-location organizations • Offering integrated VoIP communications solutions • Based on Session Initiation Protocol (SIP) standard, which enables text, voicemail, IM, etc. • Single server for complete IP applications suite • Delivering feature rich, easy-to-install, open-architecture, scalable systems at affordable prices • Creating the “big company” appearance for SMBs

4. Building on a Solid Foundation • Dozens of Product Awards • Field-tested Proven Product for 10+ Years • 10,000+ Systems Installed • 7,500+ Customers in 20+ Countries • Distribution model: Internal sales supporting200+ value added resellers

5. Investment Rationale • Market trends are increasing the opportunities • Growing adoption of VoIP • Introduction of unified communications • Large mobile work force • Scalable, integrated application platform well positioned to meet SMB market demand, particularly suited to multi-location SMBs • New management leading turnaround through Four-Point Growth Plan

6. High Growth Opportunities • Average 18% growth annually in US • Voice & data IP niche to reach $8 billion by 2010 • 23% CAGR for global IP telephone equipment $ in billions Percent of US SMBs Adopting IP PBX Worldwide IP Telephone Equipment Revenues Source: International Data Corporation (IDC), January 2003 Source: InfoTrack April, 2007

7. Flexible Workforce Creates Needs Types of Workers in Typical SMB Source: Gartner (June 2007)

8. Huge Planned Adoption of UC UC Applications in Use & Planned Use in Next 3 Years Source: Gartner (June 2007) In Use Plan to Use

9. Scalable, Flexible Multi-Site SMB Solution Supports up to 3400 extensions in 100 locations Supports 3400 extensions in 100 locations • Automated, multi-site synchronization • Integrated, distributed IP applications • Centralized or decentralized management • Local and remote administration • Full remote survivability in the event of WAN outage 9

10. Integrated Single-Server Solution

11. Competitive Advantage

12. AltiGen Delivers Efficiencies AltiGen software enables better workflow solutions for customers that increase return on investment • Reduces employee time per call • Increases customers served • Increases sales volume • Reduces customer wait time • Enables selective, modular licensing of features per location for cost effective operations

13. Solutions Provided Worldwide

14. Management Driving Growth Four-Point Growth Plan • Expand distribution channel • Introduce new revenue sources • Implement improved, targeted marketing and build company brand • Enhance product functionality and scalability

15. Expand Distribution Channel • Leverage and extend committed reseller base • Aim to grow to 300 US VAR’s by March 2008 • Build up channel sales organization • Field support for expanded channel • Establish new strategic accounts program • Direct sales to larger, multi-site organizations • Increase international presence • Initial focus: UK and northern Europe via master distributor • Improve training and sales tools • Ongoing web & field training

16. Introduce New Revenue Sources • Launch AltiGen's first-ever maintenance programs • Software assurance and hardware warranty include product support, new releases, depot repair • Mandatory year one, optional thereafter • September 2007 roll out • Provides customers with an “ever improving” system • Creates recurring revenue stream • Bring additional products to market • Complementary 3rd party products • AltiGen point solutions • OEM “add-on” software applications

17. Enhanced Marketing Direction • Goals • Revive brand, improve product image, and increase lead generation • New, Focused Messaging for Targeted Segments • Launch new web site and marketing collateral • Build presence at key industry events • Expand print and online advertising • Initiate Email and webinar prospecting campaigns • Increase and optimize Google search capabilities • Established new e-marketing initiative

18. Addressing Specific Markets and Needs

19. AltiGen Systems Sold Per Quarter

20. Strategic Product Enhancements • Presence management • Real time virtual organization view • Click to communicate capabilities • Client enhancements • Drag and drop functions (e.g., Conference, transfer) • Company, department and personal directories • Unified communications enhancements • New windows, outlook and win/mobile telephony clients • Microsoft exchange 2007 & OCS 2007 integration • Performance enhancements • Implement host media processing • Further increase multi-site scalability & redundancy

21. Microsoft’s UC Overview • Complete Communications Tools • VoIP Telephone Service • E-mail • Audio and video conferencing • Voice mail • Presence and contact information • Fax • Instant messaging • Calendars

22. AltiGen’s Integrated IP Applications Suite

23. Leveraging Microsoft’s New Exchange Server 2007 Initiative Available 2Q08

24. Integrates with Microsoft’s UC Available 2008

25. Long-term Strategic Opportunities • Technology Alliances • Extend market reach • Elevate company image • Access to large, new channels • Adds credibility to AltiGen • Acquisitions, opportunistic only • Broaden high growth market opportunities • Expand “upgradeable” customer base • Enhance product portfolio with proven point solutions

26. Financial Highlights • Q307 revenue reached $4.2M, up sequentially • Very encouraged by the 5.1 release reception • Q307 gross margin of 53% • At June 30, 2007, $10.1M in cash and short-term investments, up from March 31, 2007 of $9.8M • No debt • As of August 9, 2007, 15.6M shares outstanding

27. Experienced Management Team • Gilbert Hu, Chairman and CEO, Founder • Also founded Centrum Communications • Jerry Fleming, President and COO • Interactive Intelligence, Vonexus • Phil McDermott, CFO • 3Com, David Systems, Prentice, Northern Telecom • Mike Plumer, VP of Sales • Joined AltiGen in 1996, assumed increasing responsibilities • Simon Chouldjian, VP of Hardware Engineering • Luxcom, Hewlett-Packard, TRW • Shirley Sun, VP of Research and Development • 3Com, cofounder of Centrum Communications, Novell, Vitalink Communications

28. Summary • Large unified communications market opportunity • Introduced Four-Point Growth Plan • Expand the distribution channel • Introduce new revenue sources • Implement improved, targeted marketing • Further improve product functionality and scalability • Management delivering results • Released 5.1 • Hired key sales and marketing • Secured 30 new resellers in Q3 • Launching software assurance and hardware warranty programs