The various reactions to Amazon’s VPC announcement have been interesting to read.

Earlier today, I summarized what VPC is and isn’t, but I realize, after reading the other reactions, that I should have been clearer on one thing: Amazon VPC is not a private cloud offering. It is a connectivity option for a public cloud. If you have concerns about sharing infrastructure, they’re not going to be solved here. If you have concerns about Amazon’s back-end security, this is one more item you’re going to have to trust them on — all their technology for preventing VM-to-VM and VM-to-public-Internet communication is proprietary.

Almost every other public cloud compute provider already offers connectivity options beyond public Internet. Many other providers offer multiple types of Internet VPN (IPsec, SSL, PPTP, etc.), along with options to connect virtual servers in their clouds to colocated or dedicated equipment within the same data center, and options to connect those cloud servers to private, dedicated connectivity, such as an MPLS VPN connection or other private WAN access method (leased line, etc.).

All Amazon has done here is join the club — offering a service option that nearly all their competitors already offer. It’s not exactly shocking that customers want this; in fact, customers have been getting this from competitors for a long time now, bugging Amazon to offer an option, and generally not making a secret of their desires. (Gartner clients: Connectivity options are discussed in my How to Select a Cloud Computing Infrastructure Provider note, and its accompanying toolkit worksheet.)

Indeed, there’s likely a burgeoning market for Internet VPN termination gear of various sorts, specifically to serve the needs of cloud providers — it’s already commonplace to offer a VPN for administration, allowing cloud servers to be open to the Internet to serve Web hits, but only allow administrative logins via the backend VPN-accessed network.

What Amazon has done that’s special (other than being truly superb at public relations) is to be the only cloud compute provider that I know of to fully automate the process of dealing with an IPsec VPN tunnel, and to forego individual customer VLANs for their own layer 2 isolation method. You can expect that other providers will probably automate VPN set-up so in the future, but it’s possibly less of a priority on their road maps. Amazon is deeply committed to full automation, which is necessary at their scale. The smaller cloud providers can get away with some degree of manual provisioning for this sort of thing, still — and it should be pretty clear to equipment vendors (and their virtual appliance competitors) that automating this is a public cloud requirement, ensuring that the feature will show up across the industry within a reasonable timeframe.

Think of it this way: Amazon VPC does not isolate any resources for an individual customer’s use. It provides Internet VPN connectivity to a shared resource pool, rather than public Internet connectivity. It’s still the Internet — the same physical cables in Amazon’s data center and across the world, and the same logical Internet infrastructure, just with a Layer 3 IPsec encrypted tunnel on top of it. VPC is “virtual private” in the same sense that “virtual private” is used in VPN, not in the sense of “private cloud”.