Juniper's first router had shipped only months before the company went public, and carriers were already lining up to test it. In 1999 internet traffic was doubling at a pace that strained the routers at its core. Nearly all of those machines came from Cisco, and many were general-purpose computers doing a specialized job. Juniper built a router for the backbone from scratch, with custom chips that forwarded packets at full line speed.

A Router Split in Two

Pradeep Sindhu, a computer scientist from Xerox PARC, founded Juniper in 1996. His bet was that the internet core needed purpose-built hardware, in place of software running on general processors. Juniper split the router into two parts. A control plane made the routing decisions. A forwarding engine in silicon moved the packets. Its M40 router, released in 1998, handled far more traffic per box than competitors and won early customers among large carriers.

A Quarter Century Against Cisco

Juniper priced its offering at $34 a share in June 1999, and it became one of the most successful offerings of the era. The stock soared through 2000 as carriers raced to build capacity. Then it fell sharply when the telecom bubble burst. Juniper survived as Cisco's main rival in carrier and data center networking for a quarter century. In 2025 Hewlett Packard Enterprise completed its purchase of Juniper for about $14 billion.

Cover: Cypresses, Vincent van Gogh. Art Institute of Chicago, public domain. Chosen for a cypress, kin of the juniper.