Could satellite systems turbocharge content delivery without eating ISPs bandwidth? Cidera says yes, the solution lies in avoiding point-to-point delivery methods in favor of broadcasting content over satellite links.

by Lisa Phifer VP Core Competence, Inc. [March 1, 2001]

Content Delivery Network operators like Akamai and Digital Island speed delivery by pushing rich content to the network edge. But these CDNs rely largely on ISP partner's bandwidth to distribute content. As demand for rich content and streaming media grows, the more saturated these links become. The bandwidth consumed by streaming is 20 to 30 time greater than a static Web page. Don't be fooled by low startup costs—premium content delivery exacts a hefty recurring toll on your Internet uplink.

Fortunately, a new trend in CDN technology that can reduce startup costs and free up expensive terrestrial bandwidth through selective use of satellite networks. Broadcasting high-demand, high-bandwidth content is more efficient than point-to-point delivery over terrestrial links. Also, by circumventing Internet congestion points, satellite networks can deliver latency-sensitive content with increased reliability.

Building a broadcast backbone
Providers like Cidera, iBeam, and Loral operate high-speed satellite networks that broadcast Internet traffic—news, Web pages, streaming media—from content suppliers to ISP PoPs and large enterprises located around the globe. Founded in 1997, Cidera (formerly SkyCache) was one of the first players in this satellite content delivery market.

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Cidera's Internet Broadcast Backbone has about 750 ISP POPs under contract; about 550 are installed and operational today. According to Sriram Iyer, Director of Marketing, this puts Cidera in approximately 400 ISP networks, worldwide. "In 1999, we were exclusively in North America," said Iyer. "We opened our European office in 2Q00, and were in 100 European POPs by year end."

This year, Cidera is entering the Asian market, focusing on Japan, Korea, Thailand, and Hong Kong. "Mainland China and the Indian subcontinent continue to be a challenging area," said Iyer. "We probably have about 50 POPs under contract in Asia now."

Cidera's POP expansion can be expected to slow, tracking deployment of broadband services in emerging markets. According to Iyer, "We've grown rather rapidly, but we think we've reached a critical mass now. Our future growth path will be to use our existing footprint more efficiently."

Offloading Usenet
What can Cidera deliver over this footprint? Start with Usenet, an ideal broadcast candidate. Cidera's news server broadcasts a Usenet feed to 52" roof-mounted dishes located at every subscriber POP. Cidera broadcasts over 120 gigabytes of news per day, at speeds exceeding 12 Mbps. "The traffic offloaded from each customer's terrestrial link is worth $2000 to $5000 per month—in some areas, as much as $10,000 per month," said Iyer. "Our cost to ISPs to do this is very low."

George Carey, Managing Director of ISP Operations at BroadView Networks, concurred. "Our bandwidth averages 16 Mbps for the Cidera news feed, about 8.3 articles per second," said Carey. Equivalent terrestrial bandwidth would run BroadView approximately $350 per megabit, or $5,600 per month. That's an order of magnitude greater than BroadView's $450/month tab for Cidera Usenet.

Cidera's NNTP feed is used to populate BroadView's local news server. "We've had some trouble with dropped articles, but I think that may be a local database problem," said Carey. "Our retention time is about three days for larger articles, maybe a week for short ones."

According the BroadView Managing Director for Internet Architecture David Graves, becoming a Cidera customer was painless. "I chose Cidera based on their reputation and anticipated cost savings for the newsfeed," said Graves. "I filled out a one-page form and faxed it back. All Cidera needed from us was a single public IP address with forward and reverse DNS."

Cidera supplies the satellite dish, receiver, and service adapter (a 2U server). This equipment is remotely monitored and managed by Cidera's NOC, using terrestrial links to carry modest management traffic. The ISP provides roof space, rack space, and a 10/100 port on a LAN with Internet access. "Cidera came in for a site visit, then shipped the boxes to us," said Carey. "When Cidera came back for on-site installation, they were in and out in under four hours."

Broadcasting popular Web content
Once the dish, receiver, and service adapter are installed, they can be leveraged to receive additional services at incremental cost. For example, BroadView plans to turn up Cidera's Cache Turbocharging service by simply redirecting its own cache flow.

Cache Turbocharging broadcasts popular web content to an onboard Squid cache in each service adapter. ISP caches try to satisfy local misses by hitting the Cidera adapter, configured as an ICP sibling. Adapters relay request information to Cidera, where misses are analyzed to identify popular content on a global scale. Hot content is then pushed across the satellite network to every ISP adapter, where a few gigabytes of disk provide short-term storage for continually refreshed popular objects.

Pennsylvania Online, an ISP based in Harrisburg, credits the combination of Cache Turbocharging and Usenet with 40 percent improvement in terrestrial bandwidth efficiency. "When we acquired their product in September 1998, our goal was to lower bandwidth," said George Peace, President. "As a result, we haven't needed to add bandwidth, even though our customer base has grown by over 50 percent. Slow Web sites are found on our cache instead of out on the network. It allows us to operate as if we have a much larger pipe to the backbone."

According to a June 2000 SEC filing, an ISP's tab for Cache Turbocharging runs $350-400 per month.

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