1. IDT Powering What’s Next in Communications 01 May 2000

2. Forward-looking statements in this presentation involve a number of risks and uncertainties which are detailed in IDT’s SEC filings. Actual results may differ materially from the Company’s projections.

3. IDT is… An $800 million semiconductor solutions provider to leading-edge communications companies Growing at 40% per year Generating greater than 70% of revenues from high- growth communications customers Delivering more than 50% gross margin Demonstrating strong overall profitability — over 20% pre-tax and growing

4. Solutions for the Communications Market High-Speed SRAMs High- Performance Logic & Clock Management Communications ICs Comm Memories Comm ASSPs

5. Strong Communications Market Growth for IDT Communications Personal Computing SANs/Other Peripherals Miscellaneous 36% 34% 17% 13% Fiscal 1996 71% 8% 13% Fiscal 2000

6. IDT Communications ICs More than 40% of revenue from Communications ICs World leader in FIFOs and dualports with 70% market share growing at 40% per year Communications ASSPs growing at 100% per year Multiple families of high-margin, proprietary products

7. Key Communications Customers Alcatel Cabletron Cisco EMC Ericsson Fujitsu Emerging Companies Copper Mountain Tollbridge Extreme Networks Foundry Networks Lucent Motorola NEC Nokia Nortel Networks 3Com Orckit Hauwei Air Fiber

8. Where Are We Winning? H igh-end routers and line cards L AN switches W AN access switches X DSL network termination W ireless base stations V oice-over-IP gateways Hot Communications S et-top boxes D igital video S torage area networks Hi-Perf Apps

9. Communications and Networking Design Update SuperSync II FIFOs Cisco Ericsson Intel Lucent MTK Alcatel Switch Base station Gigabit switch Terabit router 3rd gen base station Switch

10. Communications and Networking Design Update x36 Sync Dual-Ports Ericsson Nokia Nortel NEC Fujitsu Foundry 3rd gen base station IP router Switch WAN switch Gigabit switch

11. Communications and Networking Design Update Communications ASSPs Nortel Air Fiber Nortel Siemens Orckit 3Com Ramp Networks SwitchStar PHY SwitchStar PHY SAR 3G base station Wireless ATM Switch DSLAM ADSL modem

12. Newly Introduced Products ProductApplications TSI Switch FamilyVoIP gateways 3rd gen base stations Gigabit SERDESSerial backplanes Gigabit Ethernet links x72 SuperSync II FIFOsGigabit and terabit switches Gigabit and terabit routers 9-Mbit ZBTGigabit and terabit switches Gigabit and terabit routers

13. Growth Rate (CAGR 2000-2003) 25% 31% 35% 86% 250% High-Growth Markets Shipments (2000E) 2.1 Million Units 34 Million Ports 250 million Phones 900,000 Units 400,000 Ports Sources: Dataquest, In-Stat, Semico, IDT Markets Routers 100 Mbit Switches Base Stations ADSL VoIP Gateways

14. Product Leadership #1 Share in FIFOs #1 Share in ZBT SRAM #2 Share in high-performance logic #1 Share in 25/51 Mbps PHYs #1 Share in multi-ports

15. High-End Router LAN Interface Line Card 8 x 10 / 100 Ethernet MACs CPU RC3041 Packet Dual-Port 70V3389 FIFO 72V263 ALVC Logic 1 Gbps SERDES Header FIFO 72V36110 Routing Table 4-Mbit ZBT 71V3558 L3 Lookup ASIC System Control ASIC DRAM

16. 3rd Generation Base Station SRAM DSP FIFO AIR I / F Trans SerDes or PHY Dualport Memory Voice Codec Dualport Memory Rec FIFO SRAM Mux Demux Integrated Processor Serial Backplane

17. ADSL Access Switch Header Translate 77V012 155 PHY SRAM 64K x 32 71V633 Integrated CPU SwitchStar Controller 77V500 DPI to U2 77V011 DPI to U2 77V011 SwitchStar Data Path Memory 77V400 PHY 77V1254 ADSL

18. Our strategy is paying off

19. Revenue from Operations $ Millions * Estimated Analysts’ consensus

20. Earnings Per Share (Excluding Non-operating Items) * Estimated Analysts’ consensus — tax rate changes from 5% to 20%

21. Increased Manufacturing Capacity 0.18-micron capability provides additional die output without additional wafer capacity * Forecasted

22. IDT is Positioned for Success W orld leader in the integration of high performance memory and logic for high-bandwidth applications E ngaged with the existing and emerging communications leaders A ccelerating growth in revenue — $1B runrate by fiscal Q401 O pportunity for increasing earnings and valuation S trong financial performance — revenue and earnings E xcellent new product acceptance and solid roadmaps