C475IP or A580IP - any recommendations/preferences

I'm thinking of getting a proper VOIP phone for use on our boat, we
currently have a quad C475IP at home which we like pretty well. Does
the newer A580IP offer anything more or is the C475IP better, or what?

There's not much to choose as regards price, the C475IP is a little
more expensive but not by a lot.

What sort of minimum bandwidth do these require to work decently?

--
Chris Green

tinnews@isbd.co.uk wrote:

> What sort of minimum bandwidth do these require to work decently?

Depends what codec they negotiate with the other end (or the gateway
inbetween), generally between 8 and 64kbps per call.

Andy Burns <usenet.aug2009@adslpipe.co.uk> wrote:
> tinnews@isbd.co.uk wrote:
>
> > What sort of minimum bandwidth do these require to work decently?
>
> Depends what codec they negotiate with the other end (or the gateway
> inbetween), generally between 8 and 64kbps per call.

I was looking at that, 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.

--
Chris Green

tinnews@isbd.co.uk 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.

What internet connectivity does the boat have?

Andy Burns <usenet.aug2009@adslpipe.co.uk> wrote:
> tinnews@isbd.co.uk 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.

--
Chris Green

In article <bogbo7-gi7.ln1@chris.zbmc.eu>, <tinnews@isbd.co.uk> wrote:
>Andy Burns <usenet.aug2009@adslpipe.co.uk> wrote:
>> tinnews@isbd.co.uk 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.

Gordon