What Type of VoIP Codec Do I Need?

By Neil Zawacki
Updated: September 20, 2011

What Type of VoIP Codec Do I Need?

A VoIP codec is a complex algorithm that translates an analog voice signal into a digital version. They tend to have different bandwidth and computational requirements, and some of them require royalty payments. It’s therefore a good idea to take the time to look at different VoIP codecs and determine which one you need.

Some of the most popular VoIP codecs include:

Broadvoice Codec – This VoIP codec is 16Kbps narrowband and 32Kbps wideband. It has extremely low latency (the algorithmic buffering delay is just 5ms). It is also royalty free and available through an open source license.

ITU G.711 – G.711 is an old VoIP codec – it was standardized back in 1988. It uses a high bit rate (64 Kbps), but offers superior voice quality since it doesn’t compress the signal at all. It does requires a great deal of CPU power in order to properly function, however.

ITU G.726 – G.726 is mainly used by international trunks to reduce the amount of bandwidth required. The standard bitrate is 32 Kbps, but can be set to 16, 24, or 40 Kbps. It also uses the Adaptive Differential Pulse Code Modulation scheme.

ITU G.729 – This is an ITU standard codec that offer VoIP at the low rate of 8Kbps. It requires quite a bit of CPU power, however, so some VoIP phone (particularly those from Linksys and Cisco) will be only able to handle a single channel at a time. It also requires licensing in to use the codec.

GSM – The GSM codec has a great deal of popularity outside of the United States. It divides the voice signal into blocks of 20ms, and then passes them through a speech codec that can handle 13kbps. It should be noted that the newer GSM codecs are heavily patented.

iLBC – This VoIP codec was designed by Global IP sound is available under a free (but restricted) license. It has a payload bit rate of 13.33 Kbps and an encoding frame length of 30 ms. iLBC is also highly resistance to packet loss, which in turn helps to maintain the quality of phone calls.

Speex – The Speex codec supports 2.15 to 44.2 Kbps. It is highly flexible, but consumes a great deal of CPU power – quite a bit more than the ITU G.729 or GSM. Speex is completely free, however, and works well with most internet applications.

AMR Codec – This VoIP codec supports toll quality speech at 7.4 Kbps (or higher) and can encode narrowband signals at variable rates (4.75 to 12.2 Kbps). It is also a required codec for several 2.5G/3G wireless networks, including WDMA, EDGE, and GPRS.
 

Featured Research
  • 8 Ways to Get More From Your VoIP System

    Many businesses adopt VoIP to take advantage of the cost savings without spending enough time reviewing the features and benefits made available by different solutions. If this is true for your business, there’s a good chance you could be getting more from your VoIP system in the form of even lower costs or improved employee productivity. You may even find that your current software offers features that you aren’t taking advantage of! more

  • 7 Ways the Wrong Phone System Can Haunt Your Business

    The wrong phone system could be haunting your business - and we’re talking about problems more serious than ghosts and ghouls. From increased costs to issues with scaling, we’ve identified seven important ways that a less than ideal phone system could be holding you back. You’ll be surprised at how much of a difference this can make to your bottom line too. more

  • Ditch Your Fax Servers

    An in-house fax server gives an IT department centralized management and monitoring over the entire enterprise's faxing. This can help your company track usage and better maintain records for auditing and record keeping. However, there are serious drawbacks that come with utilizing an in-house fax server solution and these range from security to cost-prohibitive pricing. more

  • The IT Manager's Survival Guide

    As an IT manager, maintaining physical fax servers and infrastructure is not a high priority. However, fax capability remains a business need simply because chances are your industry is dependent on its security. What if there was a way to reduce the amount of time spent handling fax complaints and maintaining physical servers? And this way took into account security, cost savings, and freed up your IT resources. Would you be interested? more

  • VoIP: Your New Secret Weapon for a Strong Year End

    As the end of 2017 nears, you may be feeling pressure to make sure you close the year out strong.If you’ve been sitting on the fence regarding VoIP, this may be the perfect time to switch. VoIP options had never been better or more full-featured than they are now, and it may be just the thing your business needs to see a productivity and profitability boost. more