Polycom VVX 1500: Does Ringcentral support G729 codec?

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I have  a Polycom VVX 1500 phone.  Want to make sure I am getting the best voice quality at least bandwidth.
  • Does Ringcentral support G729 codec?  
  • Is the HD Voice feature the same as G729 codec? 
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tlam747 .

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Posted 3 years ago

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Danno, Champion

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This is what my understanding is of RC:

Technically, Ring Central IP phones only need a bare minimum of 90kbps (kilobit-per-second) downstream and upstream connection to make calls.  Ring Central uses G.711 for high and G.729 for low.


G.711 (90kbps)

The G.711 algorithm is not new. It was originally introduced by Bell Systems in the 1970s and was formally standardized by the International Telecommunication Union (ITU) in 1988. Today, G.711 is commonly used in Voice over Internet Protocol (VoIP), also known as Internet telephony.

In G.711, the mu-law codec is used in North America, while the A-law codec is more common in the rest of the world. Both algorithms create a 64-Kbps digital output using an input sample rate of 8 kilohertz (kHz). G.711 employs a technology called packet loss concealment (PLC) that can minimize the practical effect of dropped packets. The effective signal bandwidth is reduced during silent periods by means of a process known as voice activation detection (VAD).


G.729 (30kbps)

G.729 has several extensions or annexes. The two most common are G.729A and G.729AB. In G.729A, input frames are 10 milliseconds (10 ms) in duration and generated frames contain 80 bits. The input and output contain 16-bit pulse-code modulation (PCM) samples converted from or to 8-Kbps compressed data. The total algorithmic delay is 15 ms. In G.729AB, the parameters are the same as in G.729A with the addition of voice activation detection (VAD) in which the effective signal bandwidth is reduced when there is no audio input. A technology known as comfort noise generation (CNG) produces a small amount of background pink noise during pauses in speech to avoid user distraction that can be caused by intervals of absolute silence.



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Derrick Bozkurt, U.S. Tier 3 Support

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RingCentral does support both G.729 and G.711 codecs, with the latter being the higher quality of the two. 

HD Voice actually uses a different codec altogether; G.722. HD Voice will work as long as both endpoint devices support that codec and are riding on RingCentral's network. This codec has the highest bandwidth requirements of the three, and would go into effect automatically once the aforementioned conditions have been met. 

Your VVX1500 is compatible with all three codecs in question. 

To learn how to change the bandwidth usage of a specific device, click here. We typically recommend keeping this setting on "High" for most applications. If you are experiencing call quality problems, you may try adjusting to the lower quality codec by selecting "Low" under this setting. 


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tlam747 .

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Derrick > Perfect!  This is exactly what I needed to know.  You rock!