WASHINGTON, D.C., September 6, 2006 - Cogent Communications Group, Inc. (NASDAQ: CCOI), the largest Ethernet Internet service provider in the United States, today announced that Dave Schaeffer, chief executive officer, will present at Jefferies 4th Annual Communications Conference being held at the Mandarin Oriental in New York. Mr. Schaeffer's presentation is scheduled for Monday, September 11, 2006 at 2:15 p.m. EDT.

Investors and other interested parties may access a live audio webcast of the presentation by going to Cogent's Investor Relations section of our website (http://www.cogentco.com/htdocs/events.php) to access the link to the live audio webcast. A replay of the webcast will be available on Cogent's IR website for 30 days following the presentation.

About Cogent Communications

Cogent Communications (NASDAQ: CCOI) is a multinational, Tier 1 facilities-based ISP recently ranked by Ovum-RHK as the largest provider of Ethernet services in the United States. Cogent specializes in providing businesses with high speed Internet access and point-to-point transport services. Cogent's facilities-based, all-optical IP network backbone spans 14 countries and provides IP services in approximately 90 markets located in North America and Europe.

Since Cogent's inception, Cogent has unleashed the benefits of IP technology, building one of the largest and highest capacity IP networks in existence. This network enables Cogent to offer large bandwidth connections at highly competitive prices. Network ownership also enables Cogent to offer superior customer support through end-to-end control of service delivery and network monitoring.

Cogent Communications is headquartered at 1015 31st Street, NW, Washington, D.C. 20007. For more information, visit www.cogentco.com. Cogent Communications can be reached in the United States at (202) 295-4200 or via email at This email address is being protected from spambots. You need JavaScript enabled to view it..

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Information in this release may involve expectations, beliefs, plans, intentions or strategies regarding the future. These forward-looking statements involve risks and uncertainties. All forward-looking statements included in this release are based upon information available to Cogent Communications Group, Inc. as of the date of the release, and we assume no obligation to update any such forward-looking statement. The statements in this release are not guarantees of future performance and actual results could differ materially from our current expectations. Numerous factors could cause or contribute to such differences. Some of the factors and risks associated with our business are discussed in Cogent's registration statements filed with the Securities and Exchange Commission and in its other reports filed from time to time with the SEC.

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