[OpenSIPS-Users] codec manipulation feature

[Jeff Pyle]

Hi Raúl,

It comes down to the service we're offering.  When a customer buys a PRI
from us, they don't care or even know in many cases it's driven by VoIP.
They're buying a PRI -- they expect PRI quality.  It is my opinion that
G.729 does not provide that quality.  But, I also do audio production, so
I'm probably a bit more sensitive to it than most folks.  Personally I can't
stand the way it sounds... like a cell phone.  (I can't stand satellite
radio for the same reason.)  There's nothing wrong with our particular
implemenation of G.729; that's just how it is.  So, our rule is G.711
wherever possible because it provides the service our customers expect.

Oh, and we're also the ISP selling the T1s in many cases.  :)  T1s are quite
common because the DSL service sucks in this area, and we can usually bring
the price of a T1 down to where it makes sense for the customer.  6mb/768kb
is a common high-end speed DSL here.  It's common for the downstream to drop
below 2mb when it rains.  Yes, it's that bad.  We simply cannot guarantee
the quality on DSL as we can on a T1, where we have QoS egress control on
both sides.  Again, back to service quality.  If anything I'd pick cable
over DSL.  It's available in most areas although the installation cost may
be more.

It would be very nice to provide a "mostly" uncompressed PRI, compressing
only when volume dictates.


- Jeff



On 6/16/09 8:43 AM, "Raúl Alexis Betancor Santana"
<rabs at dimension-virtual.com> wrote:


> Just as a comment ... if you have very bad quality with G.729, maybe your
> problem is on other place.
> 
> Having T1 line's for data, just for putting VoIP traffic ast SIP+G.711 is a
> waste of bandwidth, but that just my opinion.
> 
> Our customers uses ADSL lines ranging from 3Mb/320Kb to 10Mb/1Mb, and using
> the same line for Inet navitation + VoIP, over a 3M/320Kb line you could
> drive 5 G729 calls without any problem, and over a 10Mb/1Mb line, more than
> 12 ... so I don't undestand where you have problems with a 1.5Mb/1.5Mb line.