Support for Apache CloudStack, of all things, helped Nuage Networks win a deal with China Telecom.

After winning the deal, Nuage also got to play hero by getting CloudStack to play nice with VMware's ESXi hypervisor, a combination Nuage says hasn't been seen at scale.

It's an interesting twist to Nuage's deal with CTCC, the China Telecom cloud services branch that launched last fall. On Wednesday, the companies announced CTCC has opted to start using Nuage's Virtualized Services Platform (VSP) and its 7850 Virtualized Services Gateway.

CloudStack is an open source management framework akin to OpenStack, but it lacks OpenStack's publicity and buzz. In North America, some might call it the Frank Stallone of networking.

But the platform is thriving at some big deployments in Asia, Nuage officials say. We heard the same thing recently from Big Switch Networks, which is getting CloudStack integration requests out of Japan.

Among CloudStack's fans is China Telecom, which went all-in with the platform years ago and was determined to use it for CTCC's new data center. CloudStack is older than OpenStack and is reputed to be easier to assemble, but the networking isn't polished. "It uses VLANs, and it uses individual virtual routers per tenant. They've realized the hard way that there are scaling issues there," says Scott Sneddon, principal architect at Nuage.

Competing to build CTCC's cloud infrastructure, Nuage got into a bake-off with a large Chinese vendor — which tends to be code for Huawei or ZTE — and won partly for its distributed approach to networking, says Sunil Khandekar, Nuage's CEO.

With routing and security were pushed down into the hypervisor, virtual machines in different parts of the data center could all be networked consistently. The concept of network isolation was important to CTCC as well, because it provides a way to corral denial-of-service attacks, Khandekar says.

CTCC had been using Xen hypervisors, but after about six months of working with Nuage, the provider signed a customer that was insisting upon using a VMware environment, using vCenter and the ESX hypervisor.

The combination is outside the norm. CloudStack was briefly owned by Citrix before being submitted to the Apache incubator in 2012, so while CloudStack documentation mentions support for all the usual hypervisors, Xen got a lot of the emphasis.

Merging CloudStack and ESX wasn't impossible; it's just that the demand for the combination hasn't been there, and it hasn't shown up at scale, Nuage officials say.

"The challenges were actually around how CloudStack handles virtual machine identification, password reset — things like that. There's some plumbing within CloudStack that's unique to CloudStack," Sneddon says. "Our friends at VMware are working hard on ESX with OpenStack integration. They're not working so hard on ESX with CloudStack integration."

Nuage is giving its developments back to the CloudStack community. In fact, Nuage representatives talked about this deployment at November's CloudStack Collaboration Conference in Budapest.

All this might be heartening to anyone wanting to prove that CloudStack isn't dead. But eventually, CTCC wants to broaden to support OpenStack as well, Khandekar says.