<DIV>I use dialup connection with my IPPhones which has a buildin modem without any issue on both codec G723 and G729. I sometime get better quality on the some phone if I use dialup then when I was braodband. this happens when I call most aftrican country where the termination is not good. This is because when I use broadband the media has to through some kinds of NAT transval while the dialup normally gets public IP so no NAT transval and the media gets the shorts path.</DIV>
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<DIV>thanks</DIV>
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<DIV>Mohamed</DIV>
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<DIV><BR><BR><B><I>Jorge Crichigno <jcrichigno@conexion.com.py></I></B> wrote:</DIV>
<BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">I think the data rates with overhead are as follow:<BR><BR>----------------------------------------------------------------<BR>iLBC - 30 ms (a packet each 30 ms)<BR><BR>RTP payload: 50 bytes --> Rate: 13.3 Kbps <BR>RTP: 62 bytes<BR>UDP: 70 bytes<BR>IP: 90 bytes --> total rate: 24 Kbps<BR><BR>-------------------------------------------------------------------<BR>iLBC - 20 ms (a packet each 20 ms)<BR><BR>RTP payload: 38 bytes --> Rate: 15.2 Kbps <BR>RTP: 50 bytes<BR>UDP: 58 bytes<BR>IP: 78 bytes --> total rate: 31.2 Kbps<BR><BR>-------------------------------------------------------------------<BR>G.729 - 2 voice frame per packet<BR><BR>RTP payload: 20 bytes --> Rate: 8 Kbps <BR>RTP: 32 bytes<BR>UDP: 40 bytes<BR>IP: 60 bytes --> Total rate: 24 Kbps<BR><BR>-------------------------------------------------------------------<BR>G.729 - 4 voice frame per packet<BR><BR>RTP
payload: 40 bytes --> Rate: 8 Kbps <BR>RTP: 52 bytes<BR>UDP: 60 bytes<BR>IP: 80 bytes --> Total rate: 16 Kbps<BR><BR>-------------------------------------------------------------------<BR>G.711 - 20 ms (a packet each 20 ms)<BR><BR>RTP payload: 160 bytes --> Rate: 64 Kbps <BR>RTP: 172 bytes<BR>UDP: 180 bytes<BR>IP: 200 bytes --> Total rate: 80 Kbps<BR><BR><BR><BR>El vie, 27-05-2005 a las 10:36, Iqbal escribió:<BR>> the 5.3, 6.3K are really theoretical, i dont think they include IP <BR>> overheads, I used media_sessions.phtml, and looked at the actual calls <BR>> per codec, and I dont think u can really get a good call without 50-70K, <BR>> also most bandwidth providers (at least here in the UK) are <BR>> asymmetrical, so even on a 128K, u could have problems.<BR>> <BR>> Having said that I have done a nice call on xlite using ilbc on dial up.<BR>> <BR>> Iqbal<BR>> <BR>> Kofi Obiri-Yeboah wrote:<BR>> <BR>> >Just to add a few more
details, Greger is right to point out the quality<BR>> >inferiority of G.723 compared to those of G711 and G729. In fact, in most VOIP<BR>> >deployments, in order to quarantee interoperability, a minimum bandwidth of<BR>> >128K is specified. However to reach the wider "lower bandwidth areas" most<BR>> >service providers are opting for G.723 which uses either 5.3 or 6.3K. At this<BR>> >low bandwidth transmission needs, one could literally reach "dial up modem"<BR>> >equipped areas. in fact most VOIP phone hardware and software are begining to<BR>> >specify G.723 as their default codec. Note that until the direct media<BR>> >connection phase of a VOIP vall setup, wide bandwidth is not required. Also<BR>> >note that analogue phones have a maximim bandwidth need of 3K, hence even the<BR>> >low quality of G.723/5.3K, compared to the average analogue phone call, is<BR>> >superior<BR>> > <BR>> ><BR>> <BR>>
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