Zohar Zisapel: Father of Israeli Networking & RAD Group Founder

Zohar Zisapel (1949–2023) was the co-founder of the RAD Group — the Israeli networking and telecommunications conglomerate that produced 17 companies, multiple IPOs, and an entire generation of Israeli networking engineers. If Gil Shwed is the father of Israeli cybersecurity, Zohar Zisapel is the father of Israeli networking.

Zohar Zisapel and his brother Yehuda Zisapel founded RAD Data Communications in 1981 in Tel Aviv. The company built data communications equipment — modems, multiplexers, access devices — for telecom carriers. From RAD, the Zisapel brothers spun out a constellation of companies: RADCOM, RADVision (acquired by Avaya for $230M), Silicom, Ceragon Networks, RADWIN, and others. The model was unique: build a technology inside RAD, spin it out as an independent company, give it its own management team, and let it grow — or fail — independently.

Zohar Zisapel's RAD Model: Israel's First Systematic Company-Building Machine

Zohar Zisapel built Israel's first systematic company-building operation — predating the VC-backed incubator model by a decade. The Zisapels funded early development internally, recruited engineers from the IDF's technology units, gave each spin-out operational independence, and maintained minority ownership positions. At its peak, the RAD Group companies collectively employed over 5,000 people and generated over $1 billion in combined annual revenue.

Zohar Zisapel's model influenced an entire generation of Israeli entrepreneurs. Many engineers who built careers inside RAD Group companies went on to found their own startups. The RAD alumni network is one of the densest in Israeli tech — less visible than the Unit 8200 alumni network but arguably as influential in the networking and telecommunications infrastructure sector.

Zohar Zisapel's 17 Companies: RADVision, RADCOM, Silicom, Ceragon, and the Spin-Out Constellation

Zohar Zisapel and Yehuda Zisapel spun out 17 companies from RAD Data Communications. The most significant: RADVision (video conferencing infrastructure, acquired by Avaya for $230 million), RADCOM (network intelligence, NASDAQ: RDCM), Silicom (server adapters, NASDAQ: SILC), Ceragon Networks (wireless backhaul, NASDAQ: CRNT), and RADWIN (point-to-multipoint broadband). Each operated as an independent company with its own management and board. Zohar Zisapel held minority positions across the portfolio.

Zohar Zisapel and the Tefen Connection: Industrial Parks and the Company-Factory Model

Zohar Zisapel built the RAD Group's operations in the Tel Aviv area but drew inspiration from Stef Wertheimer's Tefen industrial park model in the Galilee. Where Wertheimer built manufacturing parks in the periphery, Zohar Zisapel built a technology conglomerate in the center — but the principle was similar: create infrastructure, recruit talent, spin out independent operations, and let the ecosystem compound.

Zohar Zisapel's Legacy: The Father of Israeli Networking (1949–2023)

Zohar Zisapel passed away in January 2023. His death marked the end of a founding era in Israeli technology — the generation that built networking infrastructure companies before venture capital, before Unit 8200 became a brand, and before "startup nation" was a phrase. The RAD Group companies Zohar Zisapel co-founded continue to operate. The engineers he trained continue to build. The model he pioneered — systematic internal spin-outs — is now the standard playbook for Israeli technology conglomerates.

Zohar Zisapel: Frequently Asked Questions

Who was Zohar Zisapel?

Zohar Zisapel (1949–2023) was an Israeli technology entrepreneur and co-founder of the RAD Group — a networking conglomerate that produced 17 companies, multiple NASDAQ IPOs, and over 5,000 employees. Known as the father of Israeli networking.

What was the RAD Group?

Zohar Zisapel and his brother Yehuda Zisapel founded RAD Data Communications in 1981 in Tel Aviv. It became a systematic company-building operation that spun out 17 companies including RADVision ($230M Avaya acquisition), RADCOM, Silicom, Ceragon Networks, and RADWIN.

How many companies did Zohar Zisapel build?

17 companies spun out of the RAD Group. Combined peak employment: 5,000+. Combined peak revenue: $1B+. Multiple NASDAQ listings.

When did Zohar Zisapel die?

Zohar Zisapel passed away in January 2023 at age 73.

What is Zohar Zisapel's relationship to Yehuda Zisapel?

Zohar and Yehuda Zisapel were brothers who co-founded the RAD Group in 1981. Together they built and spun out 17 companies from RAD Data Communications.