RE: Voice Compression

2003-11-13 Thread Ray Burkholder

There is also something out there called IAX trunking.  It can use a low
bandwidth codec and put a bunch of simultaneous conversations into fewer
packets, which helps to cut down on the high packet tax you'd normally get
with packetizing individual voice channels.  And works over any IP link.

Ray Burkholder
[EMAIL PROTECTED]
http://www.oneunified.net
704 576 5101


> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On 
> Behalf Of Bill Woodcock
> Sent: November 13, 2003 21:10
> To: Anton L. Kapela
> Cc: Robert White; [EMAIL PROTECTED]
> Subject: Re: Voice Compression
> 
> 
> 
>   On Thu, 13 Nov 2003, Anton L. Kapela wrote:
> > 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
> 
> Yep, although I haven't used it yet myself, I've been hearing it very
> widely praised, particularly for traffic flowing across 
> high-congestion
> Internet links.  Apparently it can sustain 20% packet loss without
> significant reduction in voice quality.  However, this was 
> supposed to be
> over "T1s" which I assumed to mean point-to-point serial.
> 
> -Bill
> 
> 
> 
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Re: Voice Compression

2003-11-13 Thread Bill Woodcock

  On Thu, 13 Nov 2003, Anton L. Kapela wrote:
> 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

Yep, although I haven't used it yet myself, I've been hearing it very
widely praised, particularly for traffic flowing across high-congestion
Internet links.  Apparently it can sustain 20% packet loss without
significant reduction in voice quality.  However, this was supposed to be
over "T1s" which I assumed to mean point-to-point serial.

-Bill




Re: Voice Compression

2003-11-13 Thread Anton L. Kapela

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


Re: Voice Compression

2003-11-13 Thread Spencer Wood

g729 Has pretty "Decent" voice
Quality.  Each Call is 8k Compressed.  G728 is 16k Compressed.
 Now, these values do not take into account IP Header overhead.

VoIP Equipment for 51 DS1's is not going
to be cheap.  The best bet on the Cisco Side is the 6500 or even a
router like the 7200 the with the Voice Card's.  

Again, not cheap, but it does work pretty
well..

Spencer

Spencer Wood, Network Manager
Ohio Department Of Transportation
1320 Arthur E. Adams Drive
Columbus, Ohio 43221 
E-Mail: [EMAIL PROTECTED]
Phone: 614.644.5422/Fax: 614.887.4021/Pager: 866.591.9954

*






Robert White <[EMAIL PROTECTED]>

Sent by: [EMAIL PROTECTED]
11/13/2003 03:18 PM




To
[EMAIL PROTECTED]


cc



Subject
Voice Compression









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.



Re: Voice Compression

2003-11-13 Thread Bill Woodcock

> 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.

Um, do you mean that you need to move 1248 _simultaneous calls_ across 21
T1 circuits?  There's no problem there, just pick any reasonable codec.
All you need is one that uses less than 26kbps of bandwidth, and nearly
all of them meet that criterion.  Take a look at G.729a.  It's widely
used, gives reasonably good quality, and only takes half that much
bandwidth.

-Bill




Re: Voice Compression

2003-11-13 Thread Nathan Allen Stratton

On Thu, 13 Nov 2003, Robert White wrote:

> 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.

ECI Telecom Ltd.
www.ecitele.com


><>
Nathan Stratton
nathan at robotics.net
http://www.robotics.net


Voice Compression

2003-11-13 Thread Robert White

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.