UKNOF 3 How to integrate 13 networks into one and live to tell the tale Cogent Communications st Street NW Washington DC USA Mark Schleifer VP IP Engineering

One of the World’s Largest All-Optical IP Network Diverse Inter- Continental Cogent Communications’ All Optical IP Network Key Statistics InfrastructureTransport and IP On-Net Buildings>1,000 Cogent Data Centers 28 Transport Capacity North America 80 Gbps Transport Capacity Europe 40 Gbps On-Net Data Centers >220 Colocation Space (m 2 ) 30,000 Transport Capacity Transatlantic 40 Gbps Metro Capacity On- Net Buildings 2–5 Gbps Long Distance Network (km) 35,000 Metro Networks Rings175Peering Capacity>320 GbpsPeering Traffic>125 Gbps Markets> 85km14,000 Number of BGP Sessions > 3,000 Private Peering Ratio > 90% Our Network

Cogent’s Success Story combines Organic Growth and Acquisition-based External Growth Since 2001, Cogent acquired the entire business or select assets of 13 companies. Our Milestones Acquisitions Milestones August 1999 Cogent founded November th U.S. market complete February 2002 COI listed on AMEX April 2002 Offers Off-Net Internet service & colocation November 2002 Toronto market launch January 2004 France & Spain markets launch November 2004 Launches managed security service July 2005 Cogent named largest Ethernet service provider in U.S. by Ovum-RHK September 2001 Acquires assets of NetRail February 2002 Acquires Allied Riser September 2002 Acquires major assets of FiberCity Networks April 2002 Acquires building access agreements from OnSite Access April 2002 Acquires major U.S. assets of PSINet May 2003 Acquires assets of Applied Theory February 2003 Acquires Fiber Network Solutions January 2004 Acquires LambdaNet France & Spain March 2004 Acquire fiber network & equipment in Germany out of former Carrier 1 assets August 2004 Acquires UFO September 2004 Acquires Global Access October 2004 Acquires Aleron Broadband June 2005 Cogent raises $69 million in secondary offering December 2004 Acquires NTT/Verio dedicated access business in U.S. November 2000 Backbone lit in initial 4 markets August 2004 Launches U.S. Layer 2 services September 2004 Germany market launch October 2004 Offer wholesale dial IP services

Engineering Goals Get Traffic on-net ASAP –Turn down acquired backbone –Turn down acquired Transit Consolidate multiple POPs in a city Consolidate Leased Circuits

Toolbox Tunnels –MPLS-TE –UTI/L2TPv3 BGP –Local-as War Room

2001 9/2001 – Netrail AS4006 –34 devices/15 sites –New for Cogent – Off net TDM services –Tools Used MPLS-TE Tunnels

2002 4/2002 – PSInet AS174 –~5000 off-net customers on ~250 devices –Frame Relay Backbone –New to Cogent – Frame Relay –Tools Used MPLS-TE UTI Tunnels Local-as Routers pretending to be Frame Switches

2003 2/ Fiber Network Solutions (FNSI) – AS6259 –400 Business customers on ~10 devices –Tools Used L2TPv3 Tunnels Local-as

2004 1/ LambdaNet France/Spain –EU Backbone –New for Cogent - SDH Services –Splitting off from German Network Linked IGP AS Conversion –Tools Used Local-as

2004 (Cont) 8/2004 – Unlimited Fiber Optics (UFO) – AS22099 –New for Cogent – Layer 2 Business Required buildout of Native Ethernet Backbone 9/2004 – Global Access (GATel) AS13129 –Tools Used Local-as

2004 (Cont) 10/2004 – Aleron AS4200 –Tools Used MPLS-TE Tunnels Local-as 11/2004 – Verio –~2400 Customers –Tools Used Local-as War Room

The Rest 2/2002 – OnSite Access –Primarily Building Access Agreements 2/2002 – Allied Riser (ARC) –Primarily Building Access Agreements –Assets Very helpful with PSInet Migration –Each city an Island with own AS & IPs ARIN work to consolidate records 9/2002 – FiberCity Networks –Primarily Building Access Agreements

The Rest (Cont) 5/2003 Applied Theory –Customers circuits 4/2004 Carrier 1 –German Fiber Backbone

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