asterisk-users-bounces@lists.digium.com wrote:> Hi All, > > Is it correct to say that by design, asterisk wont make use > of any cards hardware dsp capabilities ?I think it would be more accurate to say that Asterisk will be able to connect to ANY type of media device, as long as an Asterisk-compatible channel has been written for it.> I don't think that any of the hardware cards currently > supported have any dsp capabilities, but I wanted to know if > for example, in the future a driver was written for a card that did > have dsp capabilities, > would asterisk be able to make any use of it ?Cards like that already exist. Audiotronix cards have on board DSPs, and they work with Asterisk (I am not endorsing those cards -- I've never used one -- just using them as an example of existing, hardware-based-DSP cards that work with Asterisk).> I am only just starting out with asterisk, and have not fully > understood the architecture yet, but it seems that in order > to handle VoIP and PSTN seamlessly, all dsp related > functionality has to be handled by software ????A lot of DSP work happens in software, but it is not a requirement or design limitation.
Hi All, Is it correct to say that by design, asterisk wont make use of any cards hardware dsp capabilities ? I don't think that any of the hardware cards currently supported have any dsp capabilities, but I wanted to know if for example, in the future a driver was written for a card that did have dsp capabilities, would asterisk be able to make any use of it ? I am only just starting out with asterisk, and have not fully understood the architecture yet, but it seems that in order to handle VoIP and PSTN seamlessly, all dsp related functionality has to be handled by software ???? Thanks Shahed
Hi Shahed, yes you are right if you use Digium hardware "all dsp related functionality has to be handled by software". Asterisk supports also other hardware and one of them have DSP on it - Quicknet Phone/LineJACK cards ... but I'm NOT recommending you to use this hardware! Quicknet's driver is too old, it haven't been updated recently (I'm talking about the original ixj driver) and Quicknet don't offer good Linux support. If you prefer to use hardware based DSP I think that it will be better to use not a PC cards, but to find some SIP based VoIP Gateways (they have g729 and g723 codecs included) and are working very well with Asterisk. I'm recommending you this web site http://www.voip-info.org it's a very good VoIP information resource. Lubo -- --------- Appradius Project: RADIUS authentication and accounting support for Asterisk PBX http://appradius.minitelecom.org/ --------- Shahed wrote:> Hi All, > > Is it correct to say that by design, asterisk wont make use of any cards > hardware dsp capabilities ? > > I don't think that any of the hardware cards currently supported > have any dsp capabilities, but I wanted to know if for example, > in the future a driver was written for a card that did have dsp > capabilities, > would asterisk be able to make any use of it ? > > I am only just starting out with asterisk, and have not fully understood > the architecture yet, but it seems that in order to handle VoIP and PSTN > seamlessly, all dsp related functionality has to be handled by software > ???? > > Thanks > Shahed > > _______________________________________________ > Asterisk-Users mailing list > Asterisk-Users@lists.digium.com > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > >
Dear Shahed, We are in process to done hardware DSP device for coding of G.729, G.723, GSM and other speech codecs. We will support the drivers for Asterisk, SER and OpenH323. The device will be available at middle of next year. There are 6 variants of the device: - USB with 16, 32 and 64 simultaneous channels; - PCI with 64, 128 and 256 simultaneous channels. In the future the device will support Audio and Video Codecs and Windows OS. Best Regards, Miroslav Nachev S> Hi All, S> Is it correct to say that by design, asterisk wont make use of any cards S> hardware dsp capabilities ? S> I don't think that any of the hardware cards currently supported S> have any dsp capabilities, but I wanted to know if for example, S> in the future a driver was written for a card that did have dsp S> capabilities, S> would asterisk be able to make any use of it ? S> I am only just starting out with asterisk, and have not fully understood S> the architecture yet, but it seems that in order to handle VoIP and PSTN S> seamlessly, all dsp related functionality has to be handled by software ???? S> Thanks S> Shahed S> _______________________________________________ S> Asterisk-Users mailing list S> Asterisk-Users@lists.digium.com S> http://lists.digium.com/mailman/listinfo/asterisk-users S> To UNSUBSCRIBE or update options visit: S> http://lists.digium.com/mailman/listinfo/asterisk-users
Dear Shahed, If you use hardware DSP for encoding and decoding you will need of less power Host CPU. There are no difference for what you will use these codecs - I mean conference or single conversation, because for conference all codecs are converted to G.711, then mixed and then back to the original codec for each party of conference group. So, if you would like to to conference with software coding you will need of very power computer. Best Regards, Miroslav Nachev S> Thank you all for your explanations related to my question. S> I have one follow-up question though. S> When I said that all dsp related stuff has to be handled S> by software within asterisk, I was thinking of S> conferencing at the time. S> I mean in order to be able to conference a sip session with S> a PSTN call, it would have to be handled by software, even S> if both the channels had hardware dsp capabilities. Right ?? S> If you are dealing with just a single channel, then the driver S> may handle codec/echo cancelation stuff with hardware help (??) S> As an aside, what is the best way to go about learnig about S> the aritecture of asterisk, other than "using the source" ?? S> The Wiki pages are great, but I have not (yet) found any info S> about asterisks architecture itself (in depth that is). S> Some linked websites / blogs provide good info on some topics, S> but is there a good high level design doc available anywhere ? S> It would stop people like me asking so many basic questions in S> the -dev list. S> Thanks S> Shahed S> _______________________________________________ S> Asterisk-Users mailing list S> Asterisk-Users@lists.digium.com S> http://lists.digium.com/mailman/listinfo/asterisk-users S> To UNSUBSCRIBE or update options visit: S> http://lists.digium.com/mailman/listinfo/asterisk-users
Thank you all for your explanations related to my question. I have one follow-up question though. When I said that all dsp related stuff has to be handled by software within asterisk, I was thinking of conferencing at the time. I mean in order to be able to conference a sip session with a PSTN call, it would have to be handled by software, even if both the channels had hardware dsp capabilities. Right ?? If you are dealing with just a single channel, then the driver may handle codec/echo cancelation stuff with hardware help (??) As an aside, what is the best way to go about learnig about the aritecture of asterisk, other than "using the source" ?? The Wiki pages are great, but I have not (yet) found any info about asterisks architecture itself (in depth that is). Some linked websites / blogs provide good info on some topics, but is there a good high level design doc available anywhere ? It would stop people like me asking so many basic questions in the -dev list. Thanks Shahed