From nova-network to quantum

Before starting anything I’d like highlight the fact that this article was co-written with Emilien Macchi, who has a better expertise on Quantum that I do. In this article, we focused on both aspects of nova-network and quantum. We did not want to compare the two or similarly make them take each other head-on. This article is just a step back about the state of the networking in OpenStack. Basically what did we lose and what did we gain?

We are always in a bad timeline… To be honest I am. It’s time for building our Cloud and Folsom is about to be released this thursday (27th). But the point is, my knowledge of ESSEX is way better than Folsom. I needed to clarify and learned how quantum works. Is it a good solution according to our setup? A lot of questions popped into my mind. Some thoughts that I’d like to share with you, community :).


Dashboard support
Dashboard Floating IP
Multi host
Basic networking (Flat and Flat DHCP)
Use case
Sec groups
will be backported to stable/folsom
Essex : Quantum V1 / Folsom : Quantum V2
Advanced L2 Isolation, Automated routing, Highest security, SDN ready
Yes but for 1 NIC, and without namespaces
Nova Network
In Essex : Quantum V1 / In Folsom : use nova-network OR quantum V2
Basic VLAN Isolation, Basic IPAM with Melange

This article did not set out to compare the two or similaly make them take each other head-on. However, if this had been the case, some of you would have put your money on nova-network because it’s difficult to justify the benefit of Quantum if they don’t need advanced networking. Furthermore for the people who use Folsom, it’s not a mandatory requirement, which is a good decision made by the project developers. Also note that the gap between nova-network and quantum is pretty huge, people who want VLAN can simply use nova-network. At this point it’s more a scabality limitation. We both sincerely hope that you’ll find this article useful, more articles about Quantum are coming before Folsom official release, so stay tuned ;-)

One more thing, we truly advice you to have a look at this discussion on the OpenStack Dev ML launched by Dan Wendlandt, PTL Quantum.