What's So Great About Open-Source IMS?

Many people, when they hear "open source," think "oh boy, free software." But making software available under open-source terms sometimes opens up a more powerful possibility: the chance to blow up existing models and rebuild them, piece by piece.

That's what makes Metaswitch Networks' Project Clearwater -- an open-source effort for Internet Multimedia Subsystem (IMS) software, which launches Wednesday -- so promising, says Tom Nolle, principal analyst with CIMI Corp.

As Light Reading reported last week, Clearwater is an attempt to make core IMS software available under open-source licensing, the wrinkle being that this version of IMS will be tailored toward cloud-hosted services. (See IMS Gets Some Open-Source Love.)

Metaswitch is providing the initial code, which is available at projectclearwater.org, and naturally, the vendor is inviting the rest of the industry to get involved. Metaswitch's release does not mention what kind of open-source licensing Project Clearwater will use.

Part of Metaswitch's bet is that the cloud is different enough to warrant building a better IMS from scratch.

In his press-release statements Wednesday, Metaswitch CTO Martin Taylor refers to the chance to "accelerate the promise of the new software telco," breaking free from the "expensive and exceedingly vendor-centric" IMS approaches on the market.

This approach also happens to give Metaswitch an angle against bigger IMS competitors such as Alcatel-Lucent and Ericsson AB.

To Nolle, the bigger possibility coming out of Clearwater, and really out of virtualization (the dissolving of hardware-based functions into software components) in general is to redefine certain network functions, "to rework those workflows," he says.

That seems reasonable when adapting networking functions to the cloud, where the basic concept of location -- where is my application running? -- stops being fixed or even predictable.

Nolle sees other avenues where open-source IMS code could be useful, too. The nature of "4G" wireless networking seems likely to change over time, and IMS will have to change accordingly. "It's easier to do that if we've got a componentized IMS that we can diddle with," Nolle says.

His point is that it's good to see a fresh approach germinating. "I think the operators believe a lot of the componentization being done today is just taking devices and mapping them one-to-one to virtual devices," Nolle says.

The idea has been kicked around before; Nolle says he's heard Alcatel-Lucent discuss plans for virtualizing IMS, for instance.

But Nolle likes Project Clearwater because it's not based on existing products. It's starting from the ground up, as if IMS never happened in hardware and can now be crafted for the "best of all possible scenarios."

— Craig Matsumoto, Managing Editor, Light Reading