Perform RadioDNS resolutions and service lookups in node.js
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README.md

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RadioDNS node.js Library

Summary

Perform RadioDNS resolutions and service lookups in node.js.

RadioDNS was standardised in ETSI TS 103 270, RadioDNS Hybrid Radio; Hybrid lookup for radio services.

Installation

npm install --save radiodns

Usage

Add this to the top of your script

var radiodns = require('radiodns')

Then if you already have the Fully Qualified Domain Name as specified in the RadioDNS spec (ETSI TS 103 270), you can resolve it into a CNAME like so

radiodns.resolve('09580.c479.ce1.fm.radiodns.org', function(err, fqdn) {
  console.log(fqdn) // => rdns.musicradio.com
})

Or lookup a bearerURI:

radiodns.resolve('fm:ce1.c479.09580', function(err, fqdn) {
  console.log(fqdn) // => rdns.musicradio.com
})

You can also pass in the parameters required to construct the FQDN to the resolve method:

var params = {
  system: 'fm',
  frequency: 95.8,
  pi: 'c479',
  ecc: 'e1'
}

radiodns.resolve(params, function(err, fqdn) {
  console.log(fqdn) // => rdns.musicradio.com
})

To perform the next step and resolve the servers for a specific application:

var params = {
  system: 'fm',
  frequency: 95.8,
  pi: 'c479',
  ecc: 'e1'
}

radiodns.resolveApplication(params, 'radiovis', function (err, result) {
  console.log(result)
})

The resolveApplication() function will return an array of servers that serve this application. This is the same as the result of a dns.resolveSrv query.

For example:

[ { name: 'vis.musicradio.com',
    port: 61613,
    priority: 0,
    weight: 100 } ]

The broadcast systems fm, dab, drm, amss and hd are supported. The required parameters for each of these systems are:

  • fm: FM with RDS/RBDS
    • gcc: The Global Country Code
    • pi: Received RDS/RBDS Programme Identification code
    • frequency: Frequency on which the service broadcast is received in Mhz
  • dab: Digital Audio Broadcasting
    • gcc: The Global Country Code
    • eid: The Ensemble Identifier
    • sid: The Service Identifer
    • scids: The Service Component Identifier (defaults to 0)
    • uatype: The User Application Type (only for data components)
  • drm: Digital Radio Mondiale
    • sid: The Service Identifer
    • appdomain: The application domain (only for data components)
    • uatype: The User Application Type (only for data components)
  • amss: AM Signalling System
    • sid: The Service Identifer
  • hd: IBOC
    • tx: Transmitter Identifier
    • cc: Country Code

Country Resolution

For FM and DAB The library supports calculating the Global Country Code (gcc) from Extended Country Code (ecc) - see the FM example at the top.

However it is common for FM broadcasts to lack RDS ECC, a field which would otherwise confirm the country of origin of the broadcast. Other information such as the physical location of the device could be used on its own, however that doesn't consider the scenario of being on or close to a country border. This library enables the accurate resolution of the country of origin by taking as inputs the RDS PI or DAB SID and the two-letter country code of the physical location of the radio device (obtained, for example, using GPS).

var params = {
  'system': 'fm',
  'isoCountryCode': 'GB',
  'pi': 'c204',
  'frequency': 96.00
}

radiodns.resolve(params, function(err, fqdn) {
  console.log(fqdn) // => radiodns.api.bbci.co.uk
})

Passing in invalid parameters with throw an error.

For more information about country resolution, see the RadioDNS specification - ETSI TS 103 270.

Running Tests

npm test

To generate a test coverage report:

npm run coverage

License

Copyright 2017 British Broadcasting Corporation

The RadioDNS library for node.js is free software; you can redistribute it and/or modify it under the terms of the Apache License, Version 2.0.

The RadioDNS library for node.js is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Apache License, Version 2.0 for more details.