[Serusers] G723.1 vs G729

Iqbal iqbal at gigo.co.uk
Fri May 27 17:28:41 CEST 2005


which goes back to the point ur looking at a 50-70K as a rule of 
thumb...I just tell me users they need 128K to make it go nicely, on 
that they should be able to surf and talk at the same time

iqbal

Jorge Crichigno wrote:

>I think the data rates with overhead are as follow:
>
>----------------------------------------------------------------
>iLBC - 30 ms (a packet each  30 ms)
>
>  RTP payload: 50 bytes  -->  Rate: 13.3 Kbps 
>  RTP: 62 bytes
>  UDP: 70 bytes
>  IP:  90 bytes --> total rate: 24 Kbps
>  
>-------------------------------------------------------------------
>iLBC - 20 ms (a packet each 20 ms)
>
>  RTP payload: 38 bytes --> Rate: 15.2 Kbps 
>  RTP: 50 bytes
>  UDP: 58 bytes
>  IP:  78 bytes --> total rate: 31.2 Kbps
>
>-------------------------------------------------------------------
>G.729 - 2 voice frame per packet
>
>  RTP payload: 20 bytes --> Rate: 8 Kbps 
>  RTP: 32 bytes
>  UDP: 40 bytes
>  IP:  60 bytes --> Total rate: 24 Kbps
>
>-------------------------------------------------------------------
>G.729 - 4 voice frame per packet
>
>  RTP payload: 40 bytes --> Rate: 8 Kbps 
>  RTP: 52 bytes
>  UDP: 60 bytes
>  IP:  80 bytes --> Total rate: 16 Kbps
>
>-------------------------------------------------------------------
>G.711 - 20 ms (a packet each 20 ms)
>
>  RTP payload: 160 bytes --> Rate: 64 Kbps 
>  RTP: 172 bytes
>  UDP: 180 bytes
>  IP:  200 bytes --> Total rate: 80 Kbps
>
>
>
>El vie, 27-05-2005 a las 10:36, Iqbal escribió:
>  
>
>>the 5.3, 6.3K are really theoretical, i dont think they include IP 
>>overheads, I  used media_sessions.phtml, and looked at the actual calls 
>>per codec, and I dont think u can really get a good call without 50-70K, 
>>also most bandwidth providers (at least here in the UK) are 
>>asymmetrical, so even on a 128K, u could have problems.
>>
>>Having said that I have done a nice call on xlite using ilbc on dial up.
>>
>>Iqbal
>>
>>Kofi Obiri-Yeboah wrote:
>>
>>    
>>
>>>Just to add a few more details, Greger is right to point out the quality
>>>inferiority of G.723 compared to those of G711 and G729. In fact, in most VOIP
>>>deployments, in order to quarantee interoperability, a minimum bandwidth of
>>>128K is specified. However to reach the wider "lower bandwidth areas" most
>>>service providers are opting for G.723 which uses either 5.3 or 6.3K. At this
>>>low bandwidth transmission needs, one could literally reach "dial up modem"
>>>equipped areas. in fact most VOIP phone hardware and software are begining to
>>>specify G.723 as their default codec. Note that until the direct media
>>>connection phase of a VOIP vall setup, wide bandwidth is not required. Also
>>>note that analogue phones have a maximim bandwidth need of 3K, hence even the
>>>low quality of G.723/5.3K, compared to the average analogue phone call, is
>>>superior
>>> 
>>>
>>>      
>>>
>>_______________________________________________
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>>serusers at lists.iptel.org
>>http://lists.iptel.org/mailman/listinfo/serusers
>>    
>>
>
>
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>
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>




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