--- patrick@ianai.net wrote: From: "Patrick W. Gilmore" <patrick@ianai.net> : While Level 3 (who owns Digital Island, which they : bought from Savvis, who got that when they : acquired Exodus, who bought way DI back when) A clarification, just for a historical note and fun. Hello former DI peeps out there! :-) Digital Island got the Footprint CDN when we acquired Sandpiper Networks for ~$600m back in 1999. Also, Exodus (back then known as the Evil Empire to many DI folks) never acquired DI. The Cable and Wireless US Division acquired both DI and Exodus, renamed everything to "Cable and Wireless America", performed the largest mass destruction of value many of us have ever seen (I believe over a billion dollars) and then went into bankruptcy. Then Savvis bought the Footprint part. Finally, Level 3 bought Footprint from Savvis. I believe this is everything... Ahhh, the bad 'ol days... >;-) scott --- patrick@ianai.net wrote: From: "Patrick W. Gilmore" <patrick@ianai.net> To: nanog@merit.edu Cc: "Patrick W. Gilmore" <patrick@ianai.net> Subject: Re: Content Delivery Networks Date: Mon, 6 Aug 2007 20:08:06 -0400 On Aug 6, 2007, at 5:10 PM, Rod Beck wrote:

Can anyone give a breakdown of the different kinds of content deliver networks? For example, we have Akamai, which appears to be a pure Layer 3 network that is tailored to pushing relatively small files like web pages and we have Lime Light Networks, which is a mix of Layer 1 and Layer 3, that focuses on bigger files like video streams.

I am not sure why you would say Akamai is "tailored to pushing relatively small files", since I do not believe they say that anywhere. LLNW does say they are focused on larger files. (I believe LLNW claims Akamai is focused on smaller files, but do you believe what Akamai says about LLNW?) I can confirm that Akamai does not have a backbone. Neither does Panther Express, CacheFly, or Mirror Image. While Level 3 (who owns Digital Island, which they bought from Savvis, who got that when they acquired Exodus, who bought way DI back when), LLNW, and at&t all have their own backbones.

Any insights out there? And what are the major challenges in making scalable content delivery networks?

Myriad. Some are hard to overcome, some are very hard. Keyword here being "scalable" - which you failed to define. What is "scalable" to you? 100 Gbps? 500 Gbps? The latter is medium-hard in the US, the former is nearly impossible in South Africa. Which brings us to geography. Are you US-centric? European? Asian? Six continents? Just a few specific countries? Plus, as you mention above, there's file size. How about streaming vs. HTTP? Optimize for latency or throughput? Did I mention cost? Etc., etc. If someone asked "what are the major challenges in making scalable backbones?", how would you answer? -- TTFN, patrick