Lane Patterson, Chief Technologist of Equinix (EQIX), shared his thoughts on data centers and the challenges facing his industry at the 2007 Gilder Telecosm conference. He coined the term ‘bitmile’ and shed some light on how application providers such as CDN’s are adjusting their optical transport architectures to optimize cost.
Equinix provides data centers for colocation and interconnect. They build their own or lease a property from companies like Digital Realty Trust (DLR) and equip it with connectivity and additional infrastructure. Then they sublet the space to companies looking for data center space – everyone from Carriers to CDN’s to Web 2.0 service providers. Google, Yahoo and a few others build their own mega data centers – for everyone else there is Equinix. Lane used an airline analogy; they are not a carrier but more like an airport where various carriers meet to exchange passengers.
Profile of a large Equinix data center:
Lane indicated that demand for optical capacity was surging and the backbone being ‘refreshed’ with higher speed technology, except with a higher focus on cost. The metric Equinix uses is Bitmiles, defined as the cost of sending a bit a one mile. This is identical to the speed*distance/cost concept I like to use but Bitmiles is a much better word.
Equinix data centers face the same problem as carriers – when you exceed the capacity of a router chassis (or the square footage of a datacenter) the only option is to mesh chassis together. Equinix is doing this in a metro area using dark fiber from providers like AboveNet (ABVT.pk) and multiple 10G wavelengths to virtualize datacenter capacity across a metro area. They call this IBXLink, and it allows customers to place servers in separate data centers but have it appear they are locally connected. This is only possible if optical transport costs can be minimized.
Lane mentioned two approaches he felt were successfully addressing the bitmile problem.
1. Build your own WDM transport network by putting long haul optical transponders right on the router and installing standalone passive WDM filters. The resulting dirt-cheap optical network is completely passive except for EDFAs. Equinix customers will purchase optical modules such as these from Finisar (FNSR) and insert them into switching equipment. This can yield savings of 60% when compared with buying separate transport equipment, but is not manageable and requires all failure protection to be done in the router. My opinion – it’s a cheap hack but sometimes that is all one needs.
2. Stop spending money on QOS when 90% of your traffic is best effort. Move this traffic to a secondary network using best effort Ethernet L2 switching at 1/10 the per port cost when compared with high end routers. My opinion – this is the future.
Option one isn’t a new approach but the combination of pluggable optics with embedded OAM&P functionality (flexible SONET/OTN/GE provisioning) and new ultra-cheap datacenter switches like those made from Force10 is a truly disruptive solution that combines elements of both options. I believe this solution will be very attractive once this low cost hardware can implement emerging Metro Ethernet Forum standards.
While option one is good from a cost perspective at some point network manageability and protection requirements require a standalone transport solution. To the degree Equinix is focused on driving down transport costs, the fact that they are a major customer of Infinera (INFN) lends credibility to Infinera’s claims of having a lower cost transport solution.
Author owns positions in Abovenet and Finisar.