CDN Federation: A Badly-Defined Solution in 搜索 of a Real Problem?

在去年的欧洲内容交付峰会 there was a general consensus that if a CDN federation model was to ever be more than a discussion topic then some action would help it along.

我们在一天的最后一小时讨论这个话题, and we committed to supporting it in the programming on an annual basis. There was a willingness to progress the discussion and participate in a 试验 among a number of operators, and even the offer of support from a potential sponsor.

My plan had been to talk with one particular CDN leader who in my mind undeniably had a good model for CDN federation, and then to start a working project from a base provided by the sponsor.

和他谈话, 以及本周的潜在赞助商, 大约四五个月后, 有一种感觉是，市场已经发生了变化, and that CDN federation is fraught with complexities that perhaps were not evident in the autumn

The interesting thing for me has been that while there is a broad will to engage with CDN federation, I now believe that this stems from a sales and marketing perspective, 而不是从工程的角度. In effect I’m sensing that the longer running and more established a CDN, the less interest there is in a federation and this leads to some observations.

The largest CDNs have little interest in federation—they are more interested in bringing their own infrastructure footprint "into" third-party networks than establishing a working process that lets the third party a) potentially derive revenue from the deepest points in the network, and b) gives the third party visibility of their clients and traffic volumes. For a globally expanding, bullish CDN this is tantamount to enabling their competition. 这是违反直觉的.

While there are parallels with mobile virtual network operation (MVNO) in the mobile telecoms market, there are also huge differences: The CDN typically has a few valuable sources (content providers) and many destinations. The MVNO has many sources of small value and many destinations. Visibility of the clients of one MVNO by its competition doesn’t really change the status quo: There are a LOT of mobile phone users on any MVNO, 所以漫游并不代表真正的竞争威胁. However in the CDN Federation model for a global CDN providing a regional telco the insight that you are delivering terabytes of content provider A’s video to hundreds of thousands of the regional telcos’ clients sets up the telco with 信息 that enables the regional telco to ring up content provider A, take a direct feed of that content and undercut the global CDN.

另一方面, it comes as no surprise that smaller regional upstart CDNs looking for new clientele (and these could be small death-star or regional overlay CDNs) are keen to federate since they have the most to gain in terms of new revenue and market intelligence. Given they are typically of the scale that they can maintain a close developed relationship with their own clients, 减少了失去客户的风险, 太.

也, one has to ask if it isn’t just simpler to increase the peering capacity and let the CDN commercial landscape continue to evolve along fairly established rules. 在一天结束的时候, capacity provisioning is much simpler than deploying a new federation and interoperation strategy.

It’s been a while since I hit a problem with streaming that was down to insufficient core network and long haul issues; interference with my Wi-Fi because popcorn is being made in the microwave in the kitchen is frankly far more likely. 目前，CDN是一个核心的效率和成本经济, 而且与终端用户体验关系不大, and so while on the outside of the box CDN federation is about making an ever-more congested internet less congested, 事实并非如此:是的, it is true that at the very edges into the domestic and enterprise environment proper proxy caching can greatly improvce the end users experience, the upstream issue of delivering Tbps into an ISP is relatively solved. CDN federation不用太担心这个.

在一天结束的时候, it was always going to be more focussed on interchange of commercial 信息—such as rights, 征税, and subscriber management—than it was truly to do with ensuring distribution. However while any CDN wants to see what traffic a competitor is shipping, 这似乎并不是cdn真正的信息, 在他们心中, 想要提供给他们的竞争对手.

My conclusion is that CDN federation is currently very much a "badly defined solution looking for a real problem."

That said we still have a sponsor interested in backing a federation 试验, and I'm still keen to be proven wrong: If there are players out there who see a CDN federation working and would like to add the group who are interested from last year's Content Delivery Summit and perhaps the support of a sponsor, 那么请务必与我联系 dom@zjkept.com.