Daniele Orlandi wrote:
On Tuesday 10 January 2006 10:06, Boris Benko wrote:
1. I have used GRANDSTREAM BUDGETONE 101 phones. They are declaring,
they have implement G.168 cancellation measures, I at first I decided to
go with them.
You still don't understand the echo question. The echo canceller inside VoIP
phones cancels the echo introduced *BY* the phone, not the echo coming from
the line. Let alone that the phone should use an acoustic echo canceller so,
g.167, not g.168.
Daniele, relax, OK?
Here, it is clearly stated, that BT 101 (and 102, too) implements *LINE
ECHO CANCELATION*. Please, take a look:
http://www.thevoipconnection.com/store/catalog/product_16192_Grandstream_BudgeTone_BT102.html
NOT the acoustic echo canceler. FYI, it seems that GRANDSTREAM
implemented ONLY one IP phone engine and then it is used in the
budgetone and also in analog adapters, they sell. The web interface is
the same (for the phone and for the adapter - I have them both).
I have tested them and it seems they quite effectively
nullify echo from most (analog) systems I have tested.
So, your test is wrong, since you cannot cancel the remote echo with an echo
canceller that cancels local echo.
Daniele, I had two very annoying cases:
1. A PBX, connected to ISDN BRI lines (2 to 6 of them), the PANASONIC
PBX, using proprietary analog phones. This is one case.
2. The second case is the SIEMENS DECT base station, with 2 or more DECT
wireless phones attached to it. No PBX no nothing, the base station is
directly connected to the ISDN BRI.
In both cases, I have heard the annoying echo. When I used the SNOM 190
IP phone, I have clearly heard the echo in both cases. In a minute
later, I have used the BT 101 phone and the echo from the first case was
gone, but not in the second case. In both cases, SNOM 190 and BT 101
were connected to my (*), with the vISDN v0.14, asterisk is 1.0.9
version, kernel 2.6.13, the system is FC4.
Now what can I do now is to repeat the test, with bristuff this time (I
have the IBM box, with TWO FC4 systems installed, the second
installation is based on asterisk 1.2.1, bristuff 0.30.0, kernel
2.6.14). I will set the system not to cancel the echo, and use the BT101
again, to make a call to the first case.
To see, if BT 101 cancells echo, or not.
But as I said, since this echo cancellation is limited to just a bt101
phone AND somehow, the echo phenomena is NOT cancelled in one of two
very basic cases, BT 101 echo cancellation is not useful to me. And this
is what I stated in my previous mail. WHY SIEMENS DECT phone exhibits
echo it is yet to be determined. But bristuff cancells it for sure.
Regarding the acustic echo cancellation (g.167 or something close to
it).Please correct me, if I am wrong... This type of cancellation is
needed in cases, when the voice from the speaker comes to the
microphone, due to several reasons - for example when using a laptop
with speakers and the microphone.
THE BEST example for acustic echo cancellation is Skype. I'm using it
too and a friend of mine uses it too. He is using it on a laptop, with
integrated mic and speakers. When using it with Skype client 1.3, echo
HEARD ON MY SIDE rendered the conversation almost useless. Thus a friend
of mine HAD to use the headset with a microphone. Interestingly enough,
when using Skype client 1.4, he does not need to use the headset. He can
talk to me freely and I can use my laptop in the same manner, too. I'm
using the 1.4 version on my side.
Thus I assume, Skype client 1.4 introduced the acustic echo
cancellation. Am I right, or not, Daniele?
=b
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