North American Network Operators Group
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Re: Voice Compression

  • From: Anton L. Kapela
  • Date: Thu Nov 13 17:49:02 2003 
Bill Woodcock said:
>
>     > I am looking for an economical solution to compress
>     > 1248 voice DS-0s to 240 DS0s.  My application is to
>     > extend the voice and data for a call center that needs
>     > roughly 63 T-1 equivalents of bandwidth down 21
>     > physical T-1 ciscuits.

[snip]

>  Take a look at G.729a.  It's widely
> used, gives reasonably good quality, and only takes half that much
> bandwidth.

I would like to also suggest seeking devices that use "iLBC" as a
codec. I've been using this codec for interconnecting voip systems and
have been very pleased with the results.

Check it out: http://www.ilbcfreeware.org

>From the overview:

"Bitrate 13.33 kbps (399 bits, packetized in 50 bytes) for the frame
size of 30 ms and 15.2 kbps (303 bits, packetized in 38 bytes) for the
frame size of 20 ms

Basic quality higher then G.729A, high robustness to packet loss

Computational complexity in a range of G.729A

Royalty Free Codec"

--Tk