alpb <alpbozkurt78@n_o_s_p_a_m.gmail.com> wrote:
 
> The voip gateway shall handle some other voice related tasks such as echo
> cancellation, voice-activity detection etc. And, not yet but the customer
> may add G.722 wide-band codec requirement before we finalize the agreement.
 
> The linux box to be developed for the gateway will not be used for other
> tasks. It shall not have a screen at all. 
 
> Do you think if a modern Intel CPU can handle G.722 as well for 8
> simultaneous channels? We will use real-time Linux OS. We can assign
> channels to different cores of the CPU if we use a quad-core CPU.

The Linksys PAP2 runs Linux.  This is well known.  As I understand,
(but haven't tried) if you open it up, put RS232 drivers on the
serial port lines, you can connect a terminal.  I don't believe
that it is an especially fast processor.

-- glen

Hey thank you all for your responses. They are very enlighting.

The voip gateway shall handle some other voice related tasks such as echo
cancellation, voice-activity detection etc. And, not yet but the customer
may add G.722 wide-band codec requirement before we finalize the agreement.


The linux box to be developed for the gateway will not be used for other
tasks. It shall not have a screen at all. 

Do you think if a modern Intel CPU can handle G.722 as well for 8
simultaneous channels? We will use real-time Linux OS. We can assign
channels to different cores of the CPU if we use a quad-core CPU.

The sound card I mentioned is M-Audio Delta 1010LT. Linux is not mentioned
in its specs but Linux guys are talking about extensive & flawless linux
support of this card on forums.

Do you know some guys who faced this problem before me? What was their
choice?

On Jun 8, 9:08&#4294967295;pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote:
> Tim Wescott wrote:
> > On 06/08/2011 03:36 AM, Rune Allnor wrote:
>
> >> We could probably quarrel over semantics till the cows come home.
> >> In a real-time setting I'd still go for the smallest possible
> >> device that could get the job done. Simply to discourage others
> >> from elbowing in on tempting computational resources.
>
> Dr. Rune must have built many systems, especially with TCP/IP.

No, I haven't.

I have, on the other hand, handled / administrated any number
of 'dedicated' systems. Once somebody wants just a *tiny*
job done, it's far easier to elbow in on a box already present,
than buy a new box for that *tiny* other task.

>
> > Semantics:
>
> > general purpose processor that can do TCP/IP: $
> > DSP that can do TCP/IP: $$$$$$$
>
> #1
> A TCP IP stack of a WAN class is a big chunk of software heavily relying
> on dynamic memory allocation and OS services. No matter what and how,
> the minimum system for that is something like 100MHz/1MB.
>
> #2
> Semantics:
>
> A PC that can do everything: $$$
> Development cost: &#4294967295; &#4294967295; &#4294967295; &#4294967295; &#4294967295; &#4294967295;$$$$
>
> Dedicated system that can do everything: $$
> Development cost: &#4294967295; &#4294967295; &#4294967295; &#4294967295; &#4294967295; &#4294967295;$$$$$

Cost if service is not provided as expected / intended / specified:
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

Rune

Vladimir Vassilevsky <nospam@nowhere.com> wrote:
 
(snip)
> A TCP IP stack of a WAN class is a big chunk of software heavily relying 
> on dynamic memory allocation and OS services. No matter what and how, 
> the minimum system for that is something like 100MHz/1MB.

UDP is much easier in many ways.

-- glen

Tim Wescott wrote:

> On 06/08/2011 03:36 AM, Rune Allnor wrote:
> 

>> We could probably quarrel over semantics till the cows come home.
>> In a real-time setting I'd still go for the smallest possible
>> device that could get the job done. Simply to discourage others
>> from elbowing in on tempting computational resources.

Dr. Rune must have built many systems, especially with TCP/IP.

> 
> Semantics:
> 
> general purpose processor that can do TCP/IP: $
> DSP that can do TCP/IP: $$$$$$$

#1
A TCP IP stack of a WAN class is a big chunk of software heavily relying 
on dynamic memory allocation and OS services. No matter what and how, 
the minimum system for that is something like 100MHz/1MB.

#2
Semantics:

A PC that can do everything: $$$
Development cost:            $$$$

Dedicated system that can do everything: $$
Development cost:            $$$$$



Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

"Steve Underwood" <coppice@n_o_s_p_a_m.coppice.org> wrote in message 
news:AaednZB3B-
> They exist, but he isn't doing any DSP at all. Why make life hard? Use the
> right tool for the job, which is not a DSP.

It might be something like a Blackfin, though, which is kinda a hybrid? :-)

Where I used to work, we used a TI C54x DSP as a video camera controller: 
While we did *very little* "real" DSP -- just fixing up some dead pixels, as 
pretty much all CCDs have -- it worked quite well as a low-power, 
very-high-speed (100MHz) general purpose CPU as well; at the time (late '90s) 
the embedded CPU options were all much lower speed unless you went with a 
32-bit CPU, and most all of those required significant external support logic, 
memory, etc.

---Joel

On 06/08/2011 03:36 AM, Rune Allnor wrote:
> On Jun 8, 11:28 am, "Steve Underwood"
> <coppice@n_o_s_p_a_m.coppice.org>  wrote:
>>> On Jun 8, 8:10=A0am, "steveu"<steveu@n_o_s_p_a_m.coppice.org>  wrote:
>>>>> On Jun 7, 3:39=3DA0pm, "alpb"<alpbozkurt78@n_o_s_p_a_m.gmail.com>
>> wrote=
>>> :
>>>>>> Hi everybody,
>>
>>>>>> For our next project, we need to develop&  engineer a VOIP gateway
>>>> which
>>>>>> must support 8 radio channels. The codec is G.711 . The requirement
>> fo=
>>> r
>>>> t=3D
>>>>> he
>>>>>> latency of voice on the gateway is 1/4 seconds. My gut feeling says
>> th=
>>> at
>>>> =3D
>>>>> we
>>>>>> can accomplish this with by using a 8 channel professional sound
>> card
>>>>>> (~$200) and PJSIP library without using a DSP, with the help of a
>> Inte=
>>> l
>>>> i=3D
>>>>> 7
>>>>>> processor and Linux OS. But everyone says it's impossible without
>> usin=
>>> g
>>>> a
>>>>>> DSP because of the CPU overhead of RTP packets and G.711 codec
>>>> handling.
>>
>>>>>> Can I ask for your opinion? Do we really need a DSP (PCI) card?
>>
>>>>> Yes, you do need the DSP.
>>
>>>>> While it might be *technically* possible to pull this off with
>>>>> a linux box, provided you get it all to yourself and are granted
>>>>> total contorl of what it does and how, you will never succeed.
>>>>> Because you will never get that linux box all to yourself, nor
>>>>> will you be granted total control of what it does and how.
>>
>>>>> Once that box is placed inside whatever system you are working on,
>>>>> somebody - not you - will some time see it, and realize that it
>>>>> is a huge resource. And start adding bells and whistles to it.
>>>>> Once *that* happens, your application is screwed.
>>
>>>>> So get on with the DSP. That way you use only the resources
>>>>> necessary to get the job done, at the same time you protect
>>>>> those resources from future interference.
>>
>>>> That is not an argument for using a DSP. Its a pretty valid argument
>> for
>>>> using a dedicated processor.
>>
>>> Dedicated *processor*, not dedicated *PC*.
>>
>>>> For the poster's workload many MCUs will do a
>>>> much better job that a DSP. G.711 is trivial. His main work is RTP and
>>>> TCP/IP handling. Its much better *not* to do those on a DSP.
>>
>>> DSP with a network or comm interface integrated? The OP
>>> can't be the first person in history to face kind of task?
>>
>>> Rune
>>
>> They exist, but he isn't doing any DSP at all. Why make life hard? Use the
>> right tool for the job, which is not a DSP.
>
> We could probably quarrel over semantics till the cows come home.
> In a real-time setting I'd still go for the smallest possible
> device that could get the job done. Simply to discourage others
> from elbowing in on tempting computational resources.

Semantics:

general purpose processor that can do TCP/IP: $

DSP that can do TCP/IP: $$$$$$$

Why get a $25 DSP part, with all the questionable tools that goes with 
it, when you can get a $5 part that has decent tools, a Linux port, and 
all the rest?

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Jun 8, 11:28�am, "Steve Underwood"
<coppice@n_o_s_p_a_m.coppice.org> wrote:
> >On Jun 8, 8:10=A0am, "steveu" <steveu@n_o_s_p_a_m.coppice.org> wrote:
> >> >On Jun 7, 3:39=3DA0pm, "alpb" <alpbozkurt78@n_o_s_p_a_m.gmail.com>
> wrote=
> >:
> >> >> Hi everybody,
>
> >> >> For our next project, we need to develop & engineer a VOIP gateway
> >> which
> >> >> must support 8 radio channels. The codec is G.711 . The requirement
> fo=
> >r
> >> t=3D
> >> >he
> >> >> latency of voice on the gateway is 1/4 seconds. My gut feeling says
> th=
> >at
> >> =3D
> >> >we
> >> >> can accomplish this with by using a 8 channel professional sound
> card
> >> >> (~$200) and PJSIP library without using a DSP, with the help of a
> Inte=
> >l
> >> i=3D
> >> >7
> >> >> processor and Linux OS. But everyone says it's impossible without
> usin=
> >g
> >> a
> >> >> DSP because of the CPU overhead of RTP packets and G.711 codec
> >> handling.
>
> >> >> Can I ask for your opinion? Do we really need a DSP (PCI) card?
>
> >> >Yes, you do need the DSP.
>
> >> >While it might be *technically* possible to pull this off with
> >> >a linux box, provided you get it all to yourself and are granted
> >> >total contorl of what it does and how, you will never succeed.
> >> >Because you will never get that linux box all to yourself, nor
> >> >will you be granted total control of what it does and how.
>
> >> >Once that box is placed inside whatever system you are working on,
> >> >somebody - not you - will some time see it, and realize that it
> >> >is a huge resource. And start adding bells and whistles to it.
> >> >Once *that* happens, your application is screwed.
>
> >> >So get on with the DSP. That way you use only the resources
> >> >necessary to get the job done, at the same time you protect
> >> >those resources from future interference.
>
> >> That is not an argument for using a DSP. Its a pretty valid argument
> for
> >> using a dedicated processor.
>
> >Dedicated *processor*, not dedicated *PC*.
>
> >> For the poster's workload many MCUs will do a
> >> much better job that a DSP. G.711 is trivial. His main work is RTP and
> >> TCP/IP handling. Its much better *not* to do those on a DSP.
>
> >DSP with a network or comm interface integrated? The OP
> >can't be the first person in history to face kind of task?
>
> >Rune
>
> They exist, but he isn't doing any DSP at all. Why make life hard? Use the
> right tool for the job, which is not a DSP.

We could probably quarrel over semantics till the cows come home.
In a real-time setting I'd still go for the smallest possible
device that could get the job done. Simply to discourage others
from elbowing in on tempting computational resources.

Rune

>On Jun 8, 8:10=A0am, "steveu" <steveu@n_o_s_p_a_m.coppice.org> wrote:
>> >On Jun 7, 3:39=3DA0pm, "alpb" <alpbozkurt78@n_o_s_p_a_m.gmail.com>
wrote=
>:
>> >> Hi everybody,
>>
>> >> For our next project, we need to develop & engineer a VOIP gateway
>> which
>> >> must support 8 radio channels. The codec is G.711 . The requirement
fo=
>r
>> t=3D
>> >he
>> >> latency of voice on the gateway is 1/4 seconds. My gut feeling says
th=
>at
>> =3D
>> >we
>> >> can accomplish this with by using a 8 channel professional sound
card
>> >> (~$200) and PJSIP library without using a DSP, with the help of a
Inte=
>l
>> i=3D
>> >7
>> >> processor and Linux OS. But everyone says it's impossible without
usin=
>g
>> a
>> >> DSP because of the CPU overhead of RTP packets and G.711 codec
>> handling.
>>
>> >> Can I ask for your opinion? Do we really need a DSP (PCI) card?
>>
>> >Yes, you do need the DSP.
>>
>> >While it might be *technically* possible to pull this off with
>> >a linux box, provided you get it all to yourself and are granted
>> >total contorl of what it does and how, you will never succeed.
>> >Because you will never get that linux box all to yourself, nor
>> >will you be granted total control of what it does and how.
>>
>> >Once that box is placed inside whatever system you are working on,
>> >somebody - not you - will some time see it, and realize that it
>> >is a huge resource. And start adding bells and whistles to it.
>> >Once *that* happens, your application is screwed.
>>
>> >So get on with the DSP. That way you use only the resources
>> >necessary to get the job done, at the same time you protect
>> >those resources from future interference.
>>
>> That is not an argument for using a DSP. Its a pretty valid argument
for
>> using a dedicated processor.
>
>Dedicated *processor*, not dedicated *PC*.
>
>> For the poster's workload many MCUs will do a
>> much better job that a DSP. G.711 is trivial. His main work is RTP and
>> TCP/IP handling. Its much better *not* to do those on a DSP.
>
>DSP with a network or comm interface integrated? The OP
>can't be the first person in history to face kind of task?
>
>Rune

They exist, but he isn't doing any DSP at all. Why make life hard? Use the
right tool for the job, which is not a DSP.

Steve

On Jun 8, 8:10&#4294967295;am, "steveu" <steveu@n_o_s_p_a_m.coppice.org> wrote:
> >On Jun 7, 3:39=A0pm, "alpb" <alpbozkurt78@n_o_s_p_a_m.gmail.com> wrote:
> >> Hi everybody,
>
> >> For our next project, we need to develop & engineer a VOIP gateway
> which
> >> must support 8 radio channels. The codec is G.711 . The requirement for
> t=
> >he
> >> latency of voice on the gateway is 1/4 seconds. My gut feeling says that
> =
> >we
> >> can accomplish this with by using a 8 channel professional sound card
> >> (~$200) and PJSIP library without using a DSP, with the help of a Intel
> i=
> >7
> >> processor and Linux OS. But everyone says it's impossible without using
> a
> >> DSP because of the CPU overhead of RTP packets and G.711 codec
> handling.
>
> >> Can I ask for your opinion? Do we really need a DSP (PCI) card?
>
> >Yes, you do need the DSP.
>
> >While it might be *technically* possible to pull this off with
> >a linux box, provided you get it all to yourself and are granted
> >total contorl of what it does and how, you will never succeed.
> >Because you will never get that linux box all to yourself, nor
> >will you be granted total control of what it does and how.
>
> >Once that box is placed inside whatever system you are working on,
> >somebody - not you - will some time see it, and realize that it
> >is a huge resource. And start adding bells and whistles to it.
> >Once *that* happens, your application is screwed.
>
> >So get on with the DSP. That way you use only the resources
> >necessary to get the job done, at the same time you protect
> >those resources from future interference.
>
> That is not an argument for using a DSP. Its a pretty valid argument for
> using a dedicated processor.

Dedicated *processor*, not dedicated *PC*.

> For the poster's workload many MCUs will do a
> much better job that a DSP. G.711 is trivial. His main work is RTP and
> TCP/IP handling. Its much better *not* to do those on a DSP.

DSP with a network or comm interface integrated? The OP
can't be the first person in history to face kind of task?

Rune