asterisk users - Aug 2008 - Randulo: An open suggestion for the VOIP users Conference

Randy:
Kudos to you for running the outstanding VOIP user's conference.   I
have an idea to toss into this public forum. I'm hoping that you and
others will consider it & give some feedback.  The idea would be to
begin each show with comments & corrections from the previous week's
show.  Sometimes when I listen to the previous week's archive, I find
that there is misinformation that could be corrected, or even a
'dangling' question that nobody on the conference could answer.  Someone
participating in the FOLLOWING week may be more inclined to comment,
correct, and even expand on such things if there were an official place
for it.  It may also make the first part of the show more dense with
specific useful information rather than being more free-form.  Doubtless
someone going through the archives would look forward to the beginning
of the NEXT archive which would start off with dense (& corrected) key
points of the previous call.

Example:   Last week there was talk about Polycom's "HDVoice"
technology, and the term was being used interchangeably with G.722.  In
fact there are important distinctions, but someone listening might
presume that the information was correct and leave short-changed.  There
are other examples even from last week, one involving someone's claim
that there's not a way to pick up a phone and directly interface with a
voice recognition directory application without needing to press some
digits first.  As it turns out, it's easy if you know the trick.  

Id' be happy to put my money where my mouth is and kick off this
Friday's show with these examples & any others I'm not remembering
at
this moment if you think it would be well received.  Perhaps others will
do the same.
What do you think?  

Thanks!
-Karl Fife

If you want to discuss this off-list, you can email me at
voipucsug at kfife.mailworks.org.

p.s.
As it turns out, HDVoice CAN use G.722, but it can also be overlain onto
other codec's such as use G.722.1 and even G.711? [sic].  That's right,
you can have an "HDVvoice" call over the PSTN using G.711, using a
special companding overlay on top G.711.  As I understand it, the two
HDVoice compliant endpoints (Polycom, Cisco & others that license the
technology) have an in-band (but inaudible) handshake, and then begin
applying the proprietary companding overlay which extends the dynamic
range of the audio.  It sounds great even though the underlying codec is
not a wideband codec.  Certainly the sound is not as good as HDVoice
over a modern adaptive-transform codec like G.722 (1987) or even better
over G.722.1 (1999), but it's definitely a big improvement over the
"Toll-Quality" (Read: AM-Radio-Through-A-Pillow) that we're all
used to,
and it is not dependent upon having a pure-IP connection involving ENUM,
DUNDI, or other non e.164 namespaces such as SIP URI's, ITAD Subscriber
Numbers etc.  In my opinion HDVoice is it's a brilliant transition
technology.

On Thu, 07 Aug 2008 00:28:29 -0500, Karl Fife wrote:
>Example:   Last week there was talk about Polycom's "HDVoice"
>technology, and the term was being used interchangeably with G.722.  In
>fact there are important distinctions, but someone listening might
>presume that the information was correct and leave short-changed.  There
>are other examples even from last week, one involving someone's claim
>that there's not a way to pick up a phone and directly interface with a
>voice recognition directory application without needing to press some
>digits first.  As it turns out, it's easy if you know the trick.  
>
>Id' be happy to put my money where my mouth is and kick off this
>Friday's show with these examples & any others I'm not
remembering at
>this moment if you think it would be well received.  Perhaps others will
>do the same.
>What do you think?  
>
>Thanks!
>-Karl Fife
>
>If you want to discuss this off-list, you can email me at
>voipucsug at kfife.mailworks.org.
>
>p.s.
>As it turns out, HDVoice CAN use G.722, but it can also be overlain onto
>other codec's such as use G.722.1 and even G.711? [sic].  That's
right,
>you can have an "HDVvoice" call over the PSTN using G.711, using a
>special companding overlay on top G.711.  As I understand it, the two
>HDVoice compliant endpoints (Polycom, Cisco & others that license the
>technology) have an in-band (but inaudible) handshake, and then begin
>applying the proprietary companding overlay which extends the dynamic
>range of the audio.  It sounds great even though the underlying codec is
>not a wideband codec.  Certainly the sound is not as good as HDVoice
>over a modern adaptive-transform codec like G.722 (1987) or even better
>over G.722.1 (1999), but it's definitely a big improvement over the
>"Toll-Quality" (Read: AM-Radio-Through-A-Pillow) that we're
all used to,
>and it is not dependent upon having a pure-IP connection involving ENUM,
>DUNDI, or other non e.164 namespaces such as SIP URI's, ITAD Subscriber
>Numbers etc.  In my opinion HDVoice is it's a brilliant transition
>technology.  
>
Karl,

This is very interesting. Did you see that Polycom made G.722.1
available through a royalty free license earlier th
week?

http://www.polycom.com/usa/en/company/news_room/press_releases/2008/2008
0805.html

In tinkering with the three phones that I have (ip650/550 & Siemens
S685IP) they all support only G.722. At least according to the
datasheets even the Polycom models don't handle G.722.1 as yet. 

Mind you I haven' gone so far as to use Wireshark to analyse the
traffic. Just measure the bandwith used across my router and note when
the phone indicates "HD" engaged on the line button.

Do you know if the companded processing you mention is implemented in
the Soundpoint models? Just from the sound of it it could improve S/N
ratio, be perhaps not frequency response. Still, it's good that they
can improve a call over the PSTN.

So, perhaps there's more to HDVoice than just G.722. Even so, G.722 is
all that I have experienced of HDVoice in their current Soundpoint IP
phones. I suspect that some of their technology is only deployed in
their larger conferencing systems, and not in the Soundpoint lineup.

Michael
--
Michael Graves
mgraves<at>mstvp.com
http://blog.mgraves.org
o713-861-4005
c713-201-1262
sip:mjgraves at pixelpower.onsip.com
skype mjgraves