From: Hunt Lee (Hunt.Lee@telecom.co.nz)
Date: Thu Aug 05 2004 - 18:49:01 GMT-3
Sorry Bob,
My bad :( Yep, I meant to say 8kbps for G.729.
So the 8kbps for G.729 that CCO always talks about is the speed at which
the 'G.729' codec is processed / sent, whereas the 'payload' that can be
changed by this command is for the 'size' of the voice payload per
packet?
-----Original Message-----
From: Bob Sinclair [mailto:bsinclair@netmasterclass.net]
Sent: Friday, 6 August 2004 9:45 a.m.
To: Hunt Lee
Subject: Re: Dumb question - what do the codec command do on dial peer
actually represent?
Hunt,
Here is some output. Yes, the codec command lets you configure the
payload.
I am not sure where your "8bytes" rate is coming from. The rate is
8kbps
(kilobits per second, or 8000 bps).
R1(config-dial-peer)#codec g729r8 ?
bytes Specify number of voice data bytes per frame
<cr>
R1(config-dial-peer)#codec g729r8 bytes ?
Each codec sample produces 10 bytes of voice payload.
Valid sizes are:
10, 20, 30, 40, 50, 60, 70, 80, 90, 100,
110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210,
220, 230, 240.
Any other value within the range will be rounded down
to nearest valid size.
<10-244> Choose a voice payload size from the list above
HTH,
Bob Sinclair
CCIE #10427, CISSP, MCSE
www.netmasterclass.net
----- Original Message -----
From: "Hunt Lee" <Hunt.Lee@telecom.co.nz>
To: "Edwards, Andrew M" <andrew.m.edwards@boeing.com>; "Bob Sinclair"
<bsinclair@netmasterclass.net>
Cc: <ccielab@groupstudy.com>
Sent: Thursday, August 05, 2004 5:37 PM
Subject: RE: Dumb question - what do the codec command do on dial peer
actually represent?
> So for the 'codec <codec type> byte <x>' command...
>
> It is changing the 'payload', not 'rate', right?
>
> I'm a little confused, what's the rate of 8bytes of G.729 refer to
then?
>
> -----Original Message-----
> From: Edwards, Andrew M [mailto:andrew.m.edwards@boeing.com]
> Sent: Friday, 6 August 2004 9:34 a.m.
> To: Bob Sinclair; Hunt Lee
> Cc: ccielab@groupstudy.com
> Subject: RE: Dumb question - what do the codec command do on dial peer
> actually represent?
>
> Thanks Bob. Yep. Reading the chart myself... Its 20bytes. 8)
>
> -----Original Message-----
> From: Bob Sinclair [mailto:bsinclair@netmasterclass.net]
> Sent: Thursday, August 05, 2004 2:23 PM
> To: Hunt Lee; Edwards, Andrew M
> Cc: ccielab@groupstudy.com
> Subject: Re: Dumb question - what do the codec command do on dial peer
> actually represent?
>
>
> Hunt,
>
> You can determine the default codec bandwidth and payload size by
doing
> a show dial-peer voice command (after configuring either a voip or
vofr
> dial-peer). By default, the g729r8 codec sends at 8000 bps. The
> default payload is 20 bytes for voip and 30 bytes for vofr. The best
> discussion of this I have seen in print is in the Cisco Press book
Cisco
> Voice over Frame Relay, ATM and IP
>
> by Steve McQuerry, et.al.
>
> HTH,
>
> Bob Sinclair
> CCIE #10427, CISSP, MCSE
> www.netmasterclass.net
>
>
> ----- Original Message -----
> From: "Hunt Lee" <Hunt.Lee@telecom.co.nz>
> To: "Edwards, Andrew M" <andrew.m.edwards@boeing.com>
> Cc: <ccielab@groupstudy.com>
> Sent: Thursday, August 05, 2004 5:13 PM
> Subject: RE: Dumb question - what do the codec command do on dial peer
> actually represent?
>
>
> > Oh...
> >
> > Isn't the default for G.729 is 8byte whereas G.711 is 64bytes?
> >
> > Can you please elaborate a bit more on where do you find the payload
> > of G.729 to be 30bytes?
> >
> > Or any URL would be great too!!!
> >
> > Thanks,
> > Hunt
> >
> > -----Original Message-----
> > From: Edwards, Andrew M [mailto:andrew.m.edwards@boeing.com]
> > Sent: Friday, 6 August 2004 3:52 a.m.
> > To: Hunt Lee
> > Subject: RE: Dumb question - what do the codec command do on dial
peer
>
> > actually represent?
> >
> > I don't know if it came across correctly, but the default is
> > 30bytes... You are lowering it to 10 bytes therefore lowering the
> > processing delay but increasing the affect excessive jitter can have
> > on the voice quality. Basically the packets are processed faster,
but
>
> > they playback at the same rate, so when the playback buffer is
smaller
>
> > (per packet SMALLER), then delay variation can affect the overall
> > buffer... Maybe even allowing the buffer to starve (silence)...
> >
> > HTH
> >
> > -----Original Message-----
> > From: Hunt Lee [mailto:Hunt.Lee@telecom.co.nz]
> > Sent: Wednesday, August 04, 2004 6:15 PM
> > To: Edwards, Andrew M; Joe Rinehart
> > Cc: ccielab@groupstudy.com
> > Subject: RE: Dumb question - what do the codec command do on dial
peer
>
> > actually represent?
> >
> >
> > Okay. Thanks for your explanation.
> >
> > But if the command increases both 'bandwidth' & 'delay', what's the
> > point of the IOS command?
> >
> > I'm sure if it is a lose-lose situation, nobody will ever want to
use
> > that command, right?
> >
> > Thanks,
> > L.
> >
> > -----Original Message-----
> > From: Edwards, Andrew M [mailto:andrew.m.edwards@boeing.com]
> > Sent: Thursday, 5 August 2004 12:20 p.m.
> > To: Hunt Lee; Joe Rinehart
> > Cc: ccielab@groupstudy.com
> > Subject: RE: Dumb question - what do the codec command do on dial
peer
>
> > actually represent?
> >
> > The default BW for G.729ar8 is 8 kbits per second.
> >
> > The default byte count per sample for 729ar8 I believe is 30 bytes
> >
> > The larger the number of bytes encoded per sample will translate
into
> > larger delays between packets (e.g. longer to process)
> >
> > I am sure there is more too it, but that's the general idea (at
least
> > that's how I understand it). The deeper understanding is how the
> > encoded sample size has an effect on setting up traffic shaping on a
> > WAN such that you do not starve out voice packets because of the
added
>
> > delay of encoding more bytes per sample.
> >
> > andy
> >
> > -----Original Message-----
> > From: Hunt Lee [mailto:Hunt.Lee@telecom.co.nz]
> > Sent: Wednesday, August 04, 2004 2:38 PM
> > To: Joe Rinehart
> > Cc: ccielab@groupstudy.com
> > Subject: RE: Dumb question - what do the codec command do on dial
peer
>
> > actually represent?
> >
> >
> > Hi Joe,
> >
> > Thanks for your reply.
> >
> > But my question is say since the default bandwidth for G.729 is
> > 8bytes, now I have increase the bandwidth per call to 10bytes.
> >
> > By increasing to 10bytes, does it increase the delay or decrease the
> > delay per call?
> >
> > Thanks,
> > L.
> >
> >
> > -----Original Message-----
> > From: Joe Rinehart [mailto:jjrinehart@hotmail.com]
> > Sent: Thursday, 5 August 2004 9:36 a.m.
> > To: Hunt Lee
> > Subject: Re: Dumb question - what do the codec command do on dial
peer
>
> > actually represent?
> >
> > chooses the dial peer codec and the packet size
> > ----- Original Message -----
> > From: "Hunt Lee" <Hunt.Lee@telecom.co.nz>
> > To: <ccielab@groupstudy.com>
> > Sent: Wednesday, August 04, 2004 2:26 PM
> > Subject: Dumb question - what do the codec command do on dial peer
> > actually represent?
> >
> >
> > > Hi guys,
> > >
> > >
> > >
> > > What does this command do?
> > >
> > >
> > >
> > > 'codec g729ar8 bytes 10'
> > >
> > >
> > >
> > > I look it up on CCO and any books I can find, yet I still don't
> > > quite understand what it achieve.
> > >
> > >
> > >
> > > Greatly appreciated if anyone can shed some light on this.
> > >
> > >
> > >
> > > Cheers,
> > >
> > > L.
> > >
> > >
> > >
> > >
> > >
> >
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If
> > > you are not the intended recipient, you should not read it -
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> > > contact me immediately, destroy it, and do not copy or use any
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> > > of
> >
> > > this communication or disclose anything about it. Thank you.
Please
> > > note that this communication does not designate an information
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