A Note on Host Media Processing

By: Richard “Zippy” Grigonis

The pendulum of technology swings back and forth over the years. In the 1980s and 1990s, computer telephony and signal processing functions too heavily burdened the workings of computer CPUs, so plug-in boards having embedded Digital Signal Processors (DSPs) were developed to offload processing and relieve the CPU. Later, when powerful CPUs appeared, many solutions dispensed with extra hardware and ran natively on the CPU purely as software. Such Host Media Processing (HMP) Software can handle media processing tasks on general-purpose servers for gateways, converged telephony applications and video portals.

Take Dialogic (News - Alert)’s HMP Software, for example, which, when installed on a system, looks for all the world like a Dialogic board with DM3 architecture to the customer application, but in fact all media processing takes place on the host processor. Dialogic’s HMP Release 3.1 for Linux supports 3G-324M Release 99 for TDM and NbUP. It also supports G.711, G.729ab, G.723.1, G.726 and AMR-NB Codecs, native streaming and native play and record.

Dialogic’s HMP Release 3.0 for Windows supports video (H.263), T.38 and V.17 Fax, speech integration, enhanced RTP (G.723, G.729), and dual-core CPU, with densities up to 750 ports per server for voice using G.711 and 580 channels of conferencing.

One company that has definitely mastered the fine art of HMP is Aculab (News - Alert), a company perhaps best known for hardware-based products, such as the Prosody and Prosody X media processing boards that provided market-leading capabilities and channel densities since their introduction in the mid-1990s. In 2004, Aculab took its extensive knowledge of media processing requirements to provide a software version of the product, Prosody S, for use in systems utilizing host-based processing.

When asked how important HMP is to Aculab, their Global Sales and Marketing Director, Chris Gravett, says, “Host Media Processing is now a key part of Aculab’s portfolio of media processing products, giving the developer a choice of an all software product for IP-based system designs. With the continual improvements in processor power from Intel (News - Alert) and AMD, the progression to a more IP-centric communications infrastructure, and the trend for software only solutions we believe that HMP will increase in its importance.”

“Our Prosody S provides a ‘software only’ version of our DSP-based Prosody X media processing boards, for use in either a pure IP environment or behind a gateway,” says Gravett. “Prosody S has recently been updated to version 3.0 which introduced Linux support and a common API architecture with our Prosody X hardware products. Linux support gives yet more choice to the developer, and with a common API set we have made it even easier to integrate with Aculab and develop applications for Prosody X or Prosody S as required.”

“With its ability to be licensed from a single channel upwards and a full feature range included in the basic price, Prosody S presents a very attractive price per port proposition,” adds Gravett. “Aculab’s full technical support facilities are included to help customers implement their HMP solution.” “Our Prosody S HMP product is licensed via our website,” says Gravett. “The web-based licensing tool enables both regular licenses and trial or evaluation licenses to be obtained via a simple process, allowing developers to get up and running with our software very quickly. Self-management of license keys is possible, which is useful in situations such as disaster recovery when licenses have to be ported from a failed server to a new server.”

When asked if Aculab was about to unveil any new HMP developments, Gravett replied, “We will carry on with our continual development of the platform to maintain it as one of the most feature-rich HMP platforms for IP-based voice and video communications on the market today. Features in the pipeline for the near future include wideband conferencing enhancements, expansion of the supported voice/audio codecs and support for video communications.” IT

Richard Grigonis (News - Alert) is Executive Editor of TMC’s IP Communications Group.

» Internet Telephony Magazine Table of Contents