Webinar Series

Commetrex is proud to announce a Spring Webinar series. In April we ill take a deep dive into Smart FoIP, and in May we will discuss “The Long Tail and Telephony”. You will receive exact dates and times soon. We also want to try something different. Please take one minute of your time to let us know what Commetrex technologies YOU want to learn more about. Please send an email to marketing@commetrex.com and describe the topic that is of greatest interest to you.

The MX8A is Making Its Mark

You may be aware that NetGen Communications, our sister company that produces and markets Smart ATA to ITSPs and their channel, is partnering with New Rock Technologies (Shanghai) to produce additional products needed by the telecom channel to bring greater value to the SME. And next to market is the MX product line of access and trunking gateways.

These gateways solve a wide range of enterprise application problems, such as PSTN access for Asterisk, and include models from four-to-120 ports. The expansion of Smart FoIP is underway, starting with the MX8A, which offers various combinations of station and office interfaces totaling 4 or 8 ports.

But here’s the thing: the expandable 4-port unit lists for only $180 and the 8-port for $270. That means that if you have a BladeWare system that needs PSTN connectivity today but FoIP tomorrow, you can do it without add-in boards. Just drive the MX8A with the FoIP BladeWare. Including Smart ATA in the mix, you have 2-, 4-, 8-port PSTN interfaces for around $50 per port. And you don’t have to give up V.34 because it’s supported by BladeWare, Smart ATA, and the MX8A.  (The MX8A-8S is great for multi-tenant applications.)

MX8A users have commented how the benefits of Smart FoIP allow them to achieve fax success rates at near-PSTN quality levels and eliminate POTS lines.  No other ATAs can claim that!  It allows them to increase revenue, decrease costs, and eliminate headaches! It is the aspirin for fax over IP and its a great voice gateway as well.

Visit our sister-company at http://www.netgencommunications.com/products/mx-gateway-series/mx-8-multipurpose-fxsfxo-atagateway/ to learn more.



Echo Cancellation on HMP Systems

Commetrex’ G.168 Line Echo Canceller (LEC) allows the developer of telephony-endpoint products and gateways to meet the specification and speech-performance requirements of demanding enterprise and carrier applications.  The LEC is available in C-reference source code and in highly optimized versions for the Texas Instruments TMS320C6000 line of DSPs.  The LEC only requires 5.0 MCPS (mega-cycles per second) peak to execute on the ‘C6400, yielding a density of 120 channels per DSP with a 128-millisecond echo tail cancellation.  Higher densities can be achieved with shorter tail lengths.

Echo in telephony systems is noticeable in networks with greater than 50-msec delay, making echo cancellation critical for speech quality in IP networks.  Since the processing delays in IP networks aggravate echo, VoIP is magnifying the importance of LECs.  Without effective echo cancellation, IP voice is just not practicable. 

But there is a price to pay for effective echo cancellation.  LECs are compute-intensive algorithms.  So efficient implementation is important, especially in HMP systems, where the PC’s MIPS can get quickly consumed.

As implied above, the longer echo, the more MIPS required.  You’ll see specs for so-called “128-msec echo-tail cancellation.”  Some LECs use the brute-force method of cancelling a long-tail echo by computing taps or coefficients for the adaptive filter (the echo replica) for every 125-micro-second sample, which is not really practicable for anything but short-tails, such as 8- or 16-msec coverage.

Commetrex’ LEC uses a rather elegant and effective way to quickly locate the possibly multiple echoes by spacing the taps at 2-msec intervals (sub-sampled taps).  Once the echoes, which are typically on the order of 4-8-msec in duration, are located, the adaptive filter only “grows” taps around the echo, skipping coverage areas without echo.  The result is an average MCPS requirement for a 16-msec tail of 1.9 MCPS on the TI DSPs and only 3.5 MCPS for 128-msec tail.

These are DSP-based MIPS (or MCPS).  What about HMP systems?  You’re still looking at under 15-MIPS per channel.  On today’s fast multi-core machines, our LEC yields some pretty amazing system capacities.

Want to learn more?  Drop us an email, and don’t be surprised if the guru who designed this thing answers.