Newsroom Press Release

April 20, 2005

Equinix to Provide Outsourced Data Center Services for Tower Group, Inc.

Foster City, CA — April 20, 2005 — Equinix, Inc. (Nasdaq: EQIX), the leading provider of network-neutral data centers and Internet exchange services, today announced that Tower Group, Inc. (Nasdaq: TWGP) has selected one of Equinix's New York area Internet Business Exchange™ (IBX®) centers to provide an offsite data center facility. Tower Group will use this deployment to Equinix's high-performance data center in conjunction with its own IT capabilities in New Jersey to create a more flexible and reliable network infrastructure.

Tower Group, Inc., headquartered in New York City, offers property and casualty insurance products and services through its insurance company and insurance service subsidiaries. Its insurance company subsidiary, Tower Insurance Company of New York, is rated "A-" (Excellent) by A.M. Best and offers commercial insurance products to small to medium size businesses and personal insurance products to individuals. Its insurance services subsidiary, Tower Risk Management, acts as a managing general agency, adjusts claims and negotiates reinsurance terms on behalf of other insurance companies. In March 2005, Tower Group, Inc. acquired North American Lumber Insurance Company, which was subsequently renamed, Tower National Insurance Company.

The move to Equinix's New York area IBX center is expected to provide Tower Group with a flexible platform for disaster recovery, as well as an opportunity to leverage the performance and cost benefits of directly interconnecting to an aggregation of network service providers and Internet companies at a single, centralized location. Equinix's concentration of networks can enable Tower Group to reduce the costs of reaching these partners in multiple, disparate locations and through traditional local loop arrangements.

In addition to the interconnection benefits, Equinix's premium data centers provide a redundant and secure physical infrastructure for the deployment of IT operations. The power operations of each center include a high-performance backup system that ensures uninterrupted power even in the event of utility power disruption. Equinix's HVAC systems provide industry-leading environmental control, including the ability to accommodate the latest in high power density equipment such as blade servers.

Forward Looking Statements

This press release contains forward-looking statements that involve risks and uncertainties. Actual results may differ materially from expectations discussed in such forward-looking statements. Factors that might cause such differences include, but are not limited to, the challenges of acquiring, operating and constructing IBX centers and developing, deploying and delivering Equinix services; unanticipated costs or difficulties relating to the integration of IXEurope into Equinix; a failure to receive significant revenue from customers in recently built out data centers; failure to complete any financing arrangements contemplated from time to time; competition from existing and new competitors; the ability to generate sufficient cash flow or otherwise obtain funds to repay new or outstanding indebtedness; the loss or decline in business from our key customers; the results of any litigation relating to past stock option grants and practices; and other risks described from time to time in Equinix's filings with the Securities and Exchange Commission. In particular, see Equinix's recent quarterly and annual reports filed with the Securities and Exchange Commission, copies of which are available upon request from Equinix. Equinix does not assume any obligation to update the forward-looking information contained in this press release.

Equinix and IBX are registered trademarks of Equinix, Inc. Internet Business Exchange is a trademark of Equinix, Inc.