Voice over Internet Protocol (VOIP)

[ActionJaxn]

Hi LAVAG,

Looking for any help regarding using LabVIEW to set up a VOIP communications interface setup. Current searches are leading me to use a ready built .dll application. I'm wondering if there is any other reasonable way to go about this. Any information regarding previous work with voip systems built using LabVIEW would be helpful. If any more information is needed, please let me know.

Thanks.

[crelf]

Looking for any help regarding using LabVIEW to set up a VOIP communications interface setup.

I once wrote some code that acquired the signal from the mic of my soundcard and used datasocket to stream it over the network - that should work. Or try network shared variables - they're even easier (and kind-of the replacement for) datasocket.

[ActionJaxn]

Thanks for your reply, but I think that setup would probably be a problem for me as I am trying to interface the computer with LabVIEW on it with VOIP equipment that is sending data over VOIP protocol. The hardware is currently a VOIP capable card and could possibly include a VOIP server for many different communication lines. This is why I think a .dll interface may be needed, but I'm looking at all different avenues. If you have any questions, please let me know. Any help is appreciated. Thanks.

[Mellroth]

...Looking for any help regarding using LabVIEW to set up a VOIP communications interface setup...

Hi,

I'm not sure if you just want to create a proprietary VOIP application in LabVIEW, or if you want to create a h323 VOIP application?

Building a proprietary VOIP protocol could be done just as crelf suggested.

Back in 2001 we developed an IP phone test equipment, and at that time we didn't have access to LabVIEW-RT, so we went with a Linux implementation to handle the RTP communication (we also needed very low level access to the network interfaces). The codecs (g711, g723, g729ab) were downloaded from ITU-T, and just compiled for our target.

Today you can probably handle the RTP streams directly in LabVIEW-RT, but I would still use codecs downloaded from ITU-T, and not spend time developing my own set of codecs in LabVIEW.

/J

[ActionJaxn]

Hi,

I'm not sure if you just want to create a proprietary VOIP application in LabVIEW, or if you want to create a h323 VOIP application?

Building a proprietary VOIP protocol could be done just as crelf suggested.

Back in 2001 we developed an IP phone test equipment, and at that time we didn't have access to LabVIEW-RT, so we went with a Linux implementation to handle the RTP communication (we also needed very low level access to the network interfaces). The codecs (g711, g723, g729ab) were downloaded from ITU-T, and just compiled for our target.

Today you can probably handle the RTP streams directly in LabVIEW-RT, but I would still use codecs downloaded from ITU-T, and not spend time developing my own set of codecs in LabVIEW.

/J

Please bear with me as I am still new to VOIP so I am learning as I go.

At this time, I am interested in both type of applications (proprietary VOIP application and h323). The reason for that is the proprietary voip app will be used for voice as well as some control functions.

The voip application that I am interested in is either a h323 or SIP based voip application. I've tried to lookup the codecs at ITU-T with no luck. Are these codecs usable in regular LabVIEW running in a Linux OS? What programming language did you use for these codecs in Linux?

I am open to ideas as I am still in the early research stage.

Thanks for any info.

[Rolf Kalbermatter]

Please bear with me as I am still new to VOIP so I am learning as I go.

At this time, I am interested in both type of applications (proprietary VOIP application and h323). The reason for that is the proprietary voip app will be used for voice as well as some control functions.

The voip application that I am interested in is either a h323 or SIP based voip application. I've tried to lookup the codecs at ITU-T with no luck. Are these codecs usable in regular LabVIEW running in a Linux OS? What programming language did you use for these codecs in Linux?

I am open to ideas as I am still in the early research stage.

Thanks for any info.

I would quess that the codecs and the entire h323 setup on the Linux machine was probably all in C, with no LabVIEW involved in that part. Maybe it was compiled as shared library and accessed over the Call Library Node, or it could have been its own process and communicate over some TCP/IP protocol with the LabVIEW test application.

I have been looking into the possibilities of supporting SIP based VOIP through LabVIEW and came across the sipXtapi libraries, but that went never into a stage where real programming work was done (and it would require some serious DLL wrapper written in C to interface it to LabVIEW).

Rolf Kalbermatter

[ActionJaxn]

Rolf, thanks for the info. I will investigate that software package.

I'm currently looking at Conaito.com for a solution. Their package is the Conaito VoIP SIP SDK and is available at download.cnet.com. Has anybody heard of or used the voip apps at Conaito.com?

I am still very open to any ideas that anybody has regarding my voip questions. Any info would be very appreciated. Thanks.

[ActionJaxn]

Any chance that anybody else has any information regarding this subject? Thanks for any info.

[Mellroth]

The voip application that I am interested in is either a h323 or SIP based voip application. I've tried to lookup the codecs at ITU-T with no luck. Are these codecs usable in regular LabVIEW running in a Linux OS? What programming language did you use for these codecs in Linux?

I would quess that the codecs and the entire h323 setup on the Linux machine was probably all in C, with no LabVIEW involved in that part. Maybe it was compiled as shared library and accessed over the Call Library Node, or it could have been its own process and communicate over some TCP/IP protocol with the LabVIEW test application.

I'm sorry I haven't answered earlier, but this thread have not showed up in my unread content.

Rolf is pretty close in his assumptions; we had DLL's written in C to encode/decode on a windows target, and we implemented a proprietary protocol between the Windows host and the Linux server (running on a PC104) to send/receive the RTP traffic.

This way the audio communication was pretty straight forward, much like file I/O, and we could still add any new codecs to our system without having to add new codecs to the Linux server.

I did a quick search on ITU-T and come up with the following links for the codecs

http://www.itu.int/r...3.1-200605-I/en

http://www.itu.int/r...729-200701-I/en

http://www.itu.int/r...191-200509-I/en (contains G711 codec as well)

/J