Acoustic Echo Cancellation and Sound Cards

  • On November 20, 2016
Clock Synchronization Acoustic Echo Cancellation (AEC) is a method of removing the echo from the audio signal captured by the microphone. This is done by using the audio that is played to the speakers as a reference audio signal. Most AEC algorithms require that both audio signals, i.e. the signal captured from the microphone and […]
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Noise Reduction and Echo Cancellation for existing VoIP Networks

  • On November 20, 2016
Background Many times we are asked for ways to cancel noise and improve audio quality in existing telephony networks.  The majority of the requests come from call centers and SMBs that are looking for simple plug-and-play solutions to resolve audio quality issues that they are facing.  Since most of these request arise for companies that […]
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Improving Audio Quality with Analog Telephone Adapter (ATA)

  • On November 20, 2016
Background One of the first steps SMBs take towards VoIP is to add ATA to their existing analog telephone network. There are many well known brands of ATAs in the market today like Linksys PAP2, Cisco PAP2T, Grandstream HandyTone and others. Regularly we are requested to improve audio quality in such telephony systems – especially […]
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Echo Cancellation with Flash Clients

  • On November 20, 2016
Background In the beginning of this year, Adobe has released an acoustic echo cancellation as an integral part of its platform. Based on the feedback we are getting, the problem of echo was successfully reduced but not in all environments and especially not in environments that include mobile platforms.  SoliCall’s network echo cancellation technology could […]
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Why we got used to ambient noise in telephony?

  • On November 20, 2016
Background If we just got a penny every time we heard the sentence:  “Our telephone equipment provides a superb audio quality… it could not be better…”.  Unfortunately, although this sentence is commonly used, it is one of the biggest self-deception in the industry.   When your friend calls you from the Mall or from the […]
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Installing PBXMate with Elastix – Phone Setup

  • On November 19, 2016
  Background In a previous post we reviewed the basics of installing of PBXMate with Elastix. In this post we will review how to configure your phones to work with PBXMate. This post will discuss the configuration for VoIP phones.  In a future post we will review the configuration required for analogue phones.
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Tips for Installing PBXMate in a Distributed VoIP Network

  • On November 19, 2016
Background Many VoIP network administrator face a common problem that their users complain about the quality of their phone calls. The most common complains are about noise, echo and other artifacts. If the network is distributed, it becomes very difficult to analyze and control the multiple components in the network starting from the end devices […]
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Echo Cancellation, Art or Science? Part I

  • On November 18, 2016
Background First, let us apologize that this post is going to be a bit technical. Don’t worry we will try to keep it as simple as possible.  Echo cancellation, and more specifically Acoustic Echo Cancellation (AEC) is theoretically a very simple algorithm. The AEC algorithm receives a reference signal (i.e. the audio played to the […]
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Echo in VoIP and Altruism

  • On November 18, 2016
What is echo in telephony? In a nutshell, echo is the phenomena in which your voice is being played back to your speakers. Echo has been with us since the early days of telephony. In the past, when most people where using PSTN lines, echo was less disturbing due to the fact that the delay […]
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Isolating the audio in VoIP networks

  • On March 2, 2016
Background In this post we would like to share with you a rare phenomenon we have seen in few sites that once it appears, it can cause a head ache to the network administrator. As opposed to the old telephony networks that was based on dedicated physical cables per call, usually twisted pair, the cables […]
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