July 2003

The Disruptive Building Block

BY JIM MACHI

In my November 2002 column, I highlighted key new building blocks for Internet telephony products -- including moving telephony media processing tasks traditionally done using DSP algorithms to the host CPU processor. I received some e-mails asking for more detail on this trend. I�ve also noticed some hype and controversy around �host media processing� (HMP) or �soft media processing� in trade magazines, so I�ve decided to devote an entire column to HMP.

Opinions on the impact of HMP range from promising a quick and complete transition from the �DSP nightmare� or �software nirvana� to comparing it with some well-known fiascos. As I see it, the transition from DSP-based media processing to HMP will be similar to the transition from transistors to integrated circuits (ICs).

While HMP technology still covers only a subset of the media server�s needs -- on the lower end of the density and features range -- it can already be cost-effectively used in some areas where the DSP-based technology cannot. This is especially true in the voice-over-packet environment, where standard Ethernet cards can be used for interfacing with the network. This is why HMP can be called a disruptive technology. In the long run, HMP will replace -- but not totally eclipse -- DSPs in a wider range of media processing solutions.

Let�s explore why and how the HMP phenomenon is happening now, and what we can expect in the future.

WHY HMP IS DISRUPTIVE
HMP as a technology has existed for at least six years in �soft modems.� However, this was just a sustaining improvement that made modems more cost effective. It did not really create new usage scenarios or business models, which happens when HMP is combined with voice over IP because it is:

� Form factor independent. It can be used without modification with PCI, Universal PCI, CompactPCI, Advanced TCA, and other form factors.
� Packet network interface independent. It can be used without modification with 10 Mb, 100 Mb, 1 Gb, or wireless Ethernet.
� Highly flexible. HMP scales down to be configurable for just one port, making it possible to use it in applications where using DSP boards is simply inconceivable.
� A software-only product. HMP does not involve any installation, configuration, and maintenance procedures for the hardware, which can change business models for some ecosystem players.

Plus, performance of HMP is gaining even faster than Moore�s law, since it is being optimized as it evolves.

COST EFFECTIVENESS IS KEY
With Moore�s Law expected to work for at least another decade (according to a recent C-NET article), HMP technology has a significant growth potential. The price/performance ratio of processors also continues to rapidly improve. While the cost per MHz of a server (including all required hardware) was around $10 to $12 in 1996, it dropped to approximately $1 by 2002. We can expect it to drop below $0.5 by 2005 if the current trend continues. This means the cost of a standard high-volume (SHV) processing platform for building media servers will, at some point, become much more attractive than specialized DSP-based hardware.

HMP is mainly attractive for solutions that must scale down, not up. For example, it can be used to build IP media servers for the small and medium enterprise with two, four, or eight ports per system. This is a market segment where no existing IP media processing boards can be cost effectively used. Over time, HMP will scale up (some vendors already claim 200 ports per system) and expand into higher solution densities.

Another factor making HMP-based VoIP solutions easier to scale is that HMP allows these solutions to be built in a distributed fashion using open, standards-based interfaces such as SIP, MGCP, VoiceXML, and SALT.

Building HMP is not without challenges -- primarily in the area of providing real-time performance while scaling up to hundreds of ports per server on a general-purpose operating system like Windows or Linux. Meeting these challenges requires special techniques such as running the software at real time priorities in the kernel mode using high-resolution timers and a high degree of code optimization.

So HMP will not completely replace DSP-based hardware, which will still be used for solutions requiring high usage of processing resources (such as transcoding between media encoding formats) and for large-scale solutions. It will be similar to the way vacuum tubes were used (and are still used today) even after transistors were introduced.

MATURING INTO THE FUTURE
Host media processing technology has matured to the point where it is ready to be deployed in the mainstream media server solutions. Today, its main value is on the lower end. Over the next few years it will continue expanding into higher densities. Ultimately, while HMP will not completely replace DSP, it will complement it for a wide range of media processing applications.

Jim Machi is director, Product Management for the Network Processing Division of the Intel Communications Group. Intel, the world�s largest chipmaker, is also a leading manufacturer of computer, networking, and communications products. For more information, visit www.intel.com.

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