Green Linux and Green Telecom – Where do they intersect?

Green, green, everything is green. It is spring now, the hills around Silicon Valley are bright and green and everything in the yard is in full bloom. Even in our jobs everything is green in these times. You can’t watch TV or listen to the news or read a press release without hearing about Green. And of course this is all for very good reasons – even if we were in a good economy we would still have to start taking measures to reduce the energy we consume and conserve power and resources.

You may have heard a lot about Green Telecom, and like many of today’s catch phrases it can mean a lot of different things. One aspect of Green Telecom that you read a lot about is the use of alternative energy to drive base stations and wireless infrastructure, especially in emerging nations. There is a great video from Ericsson on YouTube that discusses this, and that is part of a larger sequence of videos on Green Telecom. They describe using solar energy and bio-fuels in "off-grid" countries and how people who only make a few dollars a week are willing to spend some of that money to have communication services available.

But another key topic of Green is the increased demand for power management. This is not just a Telecom issue, but is important for any IT department, Operator Data Center, Central Office or co-location server farm. Power Management is where we start to see a concerted effort and overlap between Green Linux and the Telecom industry. I recently have attended two unique and separate SIG events that discussed Power Management. The Linux Foundation Collaboration Summit in April and then just last week a SCOPE-Alliance general members meeting. Power management was a key issue that is being addressed by both groups and there is definitely an overlap. Of course you would expect that considering Linux is the most widely used operating system in new Telecom network devices being designed today.

The Linux Foundation has started a Green Linux Workgroup and is working with many different projects in support of Green Linux. Green Linux, like Telecom, can mean many things but some of the most significant work is being done around ACPI (Advanced Configuration and Power Interface). Unfortunately ACPI is targeted specifically at IA (Intel Architecture) and many Telecom devices use PowerPC or MIPs, as well as Intel. But it is a good start. Especially since many core and edge devices are larger more power-hungry devices and those often do use Intel Architecture. Check out what the Linux Foundation is doing in terms of Green Linux here.

The SCOPE-Alliance has recently started a Power Management workgroup as well. The challenge for this group is to define profiles and requirements that map the high availability functionality of the Hardware Platform Interface (HPI) specification together with ACPI and IPMI. The HPI specification from the Service Availability Forum was not really written with power management in mind, but rather the management of field replaceable units (FRUs) and has always had a fairly tight coupling with IPMI. Now, with such a strong focus on power management in the industry, the SCOPE Workgroup is looking at requirements for how ACPI can fit into a hardware management profile that manages all aspects of the hardware including power. That may seem fairly straightforward, until you start to inject virtualization and the use of a hypervisor into the formula. It is not prudent to create a management model today that does not include virtualization, but it greatly increases the complexity of hardware management. Since ACPI and HPI are not integrated, and neither is designed with the concept of a hypervisor in mind, the challenge of bringing these all together is not simple. If the purpose of the hypervisor is to abstract the hardware, and management applications are typically in user space, then getting the ACPI or HPI commands around, or through, the hypervisor is something that there is no real standard for or consensus on how to do this. Or you could just put the management directly in the hypervisor, though that increases the complexity of the hypervisor, which generally should be as ‘light’ as possible.

A lot of great minds from many different companies are working on the various ACPI, HPI and hypervisor projects. But to some extent these projects are stovepiped and not looking across at each other. It is great to see an organization like SCOPE-Alliance that is trying to bridge all of these into a single profile and set of requirements that will ultimately result in a greener Telecom industry.