Audio Aggregator 25747

[WSDH510]

Audio Aggregator 25747

RX

ncat --recv-only 24.243.9.73 25747 | aplay -f S16_LE -c 2 -r 16000

TX

arecord -f S16_LE -c 2 -r 16000 | ncat --send-only 24.243.9.73 25747

[WRKC935]

Well, I don't know that anyone here understands what this is or what a Audio Aggregator 25747 is.

A bit of a description of what you have going on here and what you are trying to accomplish might help.

Or you can keep us guessing.

 

[SteveShannon]

It seems obvious that the “Audio Aggregator” combines audio from multiple sources so a person can hear them using a single set of headphones and enables them to route other audio elsewhere, but there’s no telling what the OP’s point is, whether they have a question or are just using the forum as a documentation archive.

[WSDH510]

9 hours ago, WRKC935 said:

Well, I don't know that anyone here understands what this is or what a Audio Aggregator 25747 is.

A bit of a description of what you have going on here and what you are trying to accomplish might help.

Or you can keep us guessing.

 

Audio Aggregator 25747 is a system that radio/repeater operators can connect to using Advanced Linux Sound Architecture and NETCAT on internet port 25747 to facilitate the transmission and reception of radio audio.

The purpose/goal of the project is to facilitate high quality audio in low power radios.

Important to note that internet scanners may catch the audio on internet port 25747 as the audio is open like a radio.

[WSDH510]

4 hours ago, SteveShannon said:

It seems obvious that the “Audio Aggregator” combines audio from multiple sources so a person can hear them using a single set of headphones and enables them to route other audio elsewhere, but there’s no telling what the OP’s point is, whether they have a question or are just using the forum as a documentation archive.

Yes; the goal of Audio Aggregator 25747 is to combine audio in a many-to-many audio structure where there may be multiple audio inputs and multiple audio outputs similar to a radio.

A question that I have is; is this audio structure similar to existing networks of radios?

[SteveShannon]

7 hours ago, WSDH510 said:

Yes; the goal of Audio Aggregator 25747 is to combine audio in a many-to-many audio structure where there may be multiple audio inputs and multiple audio outputs similar to a radio.

A question that I have is; is this audio structure similar to existing networks of radios?

No. Existing networks have either primitive routing (everyone goes for the ride) or no routing.

It’s more like a one to many relationship. 

[WSDH510]

1 hour ago, SteveShannon said:

No. Existing networks have either primitive routing (everyone goes for the ride) or no routing.

It’s more like a one to many relationship. 

Ok; the many-to-many audio structure is fundamental to the Audio Aggregator 25747 protocol in the spirit of two-way radios. The protocol uses port 25747 for open audio like a radio which is not encrypted. The Audio Aggregator 25747 protocol is defined as follows; 2 channel stereo at 16k Hz little-endian (S16_LE on ALSA) over port 25747 using netcat or specifically a derivative of netcat called ncat. The protocol is open and meant to be used peer-to-peer like a two-way radio.

The development of Audio Aggregator 25747 may be monitored on port 25747 of the internet or on GMRS radio in San Antonio, Texas.

[Hoppyjr]

I’m kinda confused…. all of this seems like an answer to questions no one here asked. ???

[WRKC935]

5 hours ago, Hoppyjr said:

I’m kinda confused…. all of this seems like an answer to questions no one here asked. ???

Yeah, I am in agreement.  I am guessing that they are using this to link repeaters and radios together.  But that is already handled with the MYGMRS system.

And, if you are knowledgeable enough, there are ways of connecting 'headphones' to that system as well.  And a Microphone.  For that matter, you COULD connect an IP phone to your node and use that as well due to every node being a full PBX.  But I really am not going down that rabbit hole. 

 

[WSAD526]

https://www.ebay.com/p/26026728589

[WSAD526]

Files for a GMRS LIVE radioless node-

https://www.gmrslive.com/index.php/downloads/

 

[WSAD526]

GMRS LIVE Image-

GMRSLive v2.1.3.zip

[WSDH510]

The aggregator is functioning with Sound eXchange (SoX) cross-platform on Linux/Mac/Windows!

 

[Hoppyjr]

Still going to need a bit more explanation as to what the hell’s going on here.

[WSDH510]

15 minutes ago, Hoppyjr said:

Still going to need a bit more explanation as to what the hell’s going on here.

The aggregator uses NCAT which is a derivative of NETCAT to receive open S16_LE audio from ALSA/SoX on port 25747 and then extends the open S16_LE audio back out to the internet on port 25747.

The aggregator may be monitored on Linux/Mac/Windows with Sound eXchange (SoX) using the following command:

nc 24.243.9.73 25747 | ./play -t s16 --endian little -c 2 -r 16000 -

[SteveShannon]

1 minute ago, WSDH510 said:

The aggregator uses NCAT which is a derivative of NETCAT to receive open S16_LE audio from ALSA/SoX on port 25747 and then extends the open S16_LE audio back out to the internet on port 25747.

The aggregator may be monitored on Linux/Mac/Windows with Sound eXchange (SoX) using the following command:

nc 24.243.9.73 25747 | ./play -t s16 --endian little -c 2 -r 16000 -

Okay, but how does it apply to GMRS?  Our conversations still cannot be individually routed or muxed. There’s still just one conversation per channel, audible to everyone else within range. How does this benefit us?

[WSDH510]

6 minutes ago, SteveShannon said:

Okay, but how does it apply to GMRS?  Our conversations still cannot be individually routed or muxed. There’s still just one conversation per channel, audible to everyone else within range. How does this benefit us?

The aggregator applies to GMRS because it is one potential method to link systems of computer<-->radio nodes with no encryption involved.

[Hoppyjr]

The aggregator uses NCAT which is a derivative of NETCAT to receive open S16_LE audio from ALSA/SoX on port 25747 and then extends the open S16_LE audio back out to the internet on port 25747.
The aggregator may be monitored on Linux/Mac/Windows with Sound eXchange (SoX) using the following command:
nc 24.243.9.73 25747 | ./play -t s16 --endian little -c 2 -r 16000 -

Well that clears it right up!

[SteveShannon]

14 minutes ago, WSDH510 said:

The aggregator applies to GMRS because it is one potential method to link systems of computer<-->radio nodes with no encryption involved.

Thank you.  How does a person selectively connect to another node? DTMF?  

[WSDH510]

11 minutes ago, SteveShannon said:

Thank you.  How does a person selectively connect to another node? DTMF?  

I'm trying to figure that out but I don't know yet; the different systems of nodes have different numbering schemas so some sort of resolver is probably the way to go; kinda like GMRS<-->HAM resolvers that link callsigns together.

[SteveShannon]

1 hour ago, WSDH510 said:

I'm trying to figure that out but I don't know yet; the different systems of nodes have different numbering schemas so some sort of resolver is probably the way to go; kinda like GMRS<-->HAM resolvers that link callsigns together.

I don’t use repeater networking on gmrs, but I know that for DMR each node has its own ID number. There are different networks with Brandmeister being the largest by far. But in order to prevent conflicts all of the ID numbers are doled out by a single clearinghouse. So my brandmeister ID isn’t a duplicate of one on MARC or Western States DMR network. That also allows gateways between the different networks. 
 

[WSDH510]

1 hour ago, SteveShannon said:

I don’t use repeater networking on gmrs, but I know that for DMR each node has its own ID number. There are different networks with Brandmeister being the largest by far. But in order to prevent conflicts all of the ID numbers are doled out by a single clearinghouse. So my brandmeister ID isn’t a duplicate of one on MARC or Western States DMR network. That also allows gateways between the different networks. 
 

Ok thank you; the goal of the aggregator is to somehow avoid the central clearinghouse issue but it is difficult to make a true peer<-->peer aggregator because of numerous issues including protocol information distribution, conflicts of numbering schemas (as mentioned), and peer prioritization; networks of any kind including radio networks tend to merge towards centralization which is unfortunate but it is reality; though ideally in a world of two-way radios there isn't a central clearinghouse issuing the schema.