Category: cloud

The question of high-availability cloud services (let’s agree reliable in this context really means highly available) pops up every time I discuss cloud networking requirements with enterprise-focused experts. While it’s obvious the software- and platform services must be highly available (as their users have few mechanisms to increase their availability), Infrastructure-as-a-Service (IaaS) remains a grey area.

However, once you look at the question from the business perspective, it seems Amazon probably made a pretty good choice: offer reasonably-available service at a low price. Here’s what I wrote on this topic for a web site that disappeared in the haze of URL restructuring in the meantime.

In one of my vCloud Director Networking Infrastructure rants I wrote “if they had decided to use IP encapsulation, I would have applauded.” It’s time to applaud: Cisco has just demonstrated Nexus 1000V supporting MAC-over-IP encapsulation for vCloud Director isolated networks at VMworld, solving at least some of the scalability problems MAC-in-MAC encapsulation has.

Nexus 1000V VEM will be able to (once the new release becomes available) encapsulate MAC frames generated by virtual machines residing in isolated segments into UDP packets exchanged between VEMs.

Building large-scale VLANs to support IaaS services is every data center designer’s nightmare and the low number of VLANs supported by some data center gear is not helping anyone. However, as Anonymous Coward pointed out in a comment to my Building a Greenfield Data Center post, service providers have been building very large (and somewhat stable) layer-2 transport networks for years. It does seem like someone is trying to reinvent the wheel (and/or sell us more gear).