10-11-2010, 06:44 PM
| | Re: C475IP or A580IP - any recommendations/preferences
In article <email@example.com>, <firstname.lastname@example.org> wrote:
>Andy Burns <email@example.com> wrote:
>> firstname.lastname@example.org wrote:
>> > the C475IP at home simply has a list of
>> > possible Codecs:-
>> > G722
>> > G721
>> > G726
>> > G729
>> > These are all listed under the 'Selected Codecs' column, I could
>> > remove one or more of them to see what happens I guess.
>> the G.711 and G.721 ones are the greediest, however they're effectively
>> the backstop codecs that almost everything should support, so you might
>> get failed calls if you disable them.
>Oops, that should say G711 not G721 of course (as you guessed/assumed).
>> What internet connectivity does the boat have?
>A 3G dongle so the bandwidth varies considerably depending on what
>sort of connection it negotiates.
Using VoIP (SIP) there is a 16Kb/sec overhead to the codec payload. So
G711 is 64Kbps + 16Kbps = 80Kbbps *each way*
G729 is 8Kbps + 16Kbps = 24Kbps *each way*
I've made VoIP video calls over 3G before (220Kbps each way) - a lot
will depend on where you are and what network you're using.